VC4 500 IDEX - 125hz Peak

[dire laurel]

Man I am so close to finally having Y serviceable, anyone have any idea what the 125hz hump is?

[grave plover]

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[dire laurel]

I've had a couple people ask me how I got such a clean Y spike on IDEX, so adding the info here:

NOTE: At these tensions, despite producing a really nice graph, I did have a belt keeper give way. Keeping these notes here for discussion or perhaps find a better way to tension these cleanly.

~~I think the issue is the toolhead belts and hybrid belts need to be exactly right from one another tensionwise, else it's like a couple people playing tug of war and pulling the rope at the wrong time (which in this case, would translate to X vibrations in the Y movement). Here's what I did:

1. Get your hybrid belts to low-mid tension level and equal to one another,
2. Home your printer, so that the T0 toolhead is sitting middle of the bed like it would be in a shaper test,
3. That 40hz peak is the peak you want to drive way up while getting rid of the others (at least it was in mine in the screenshot at the start of the thread, adjust based on your machine's response). In realtime analyzer, set it to toolhead 0 and oscillate Y axis at that frequency. You'll likely see a lot of Y and also X activity in it,
4. Start slowly tightening your toolhead belts, a couple degrees at a time, evenly. Basically just turn one slightly tighter, then the other. You'll hopefully start seeing the X activity decreasing in the realtime graph, and Y activity growing. You may have to do this a couple dozen times before you eventually hit a point where the X activity falls completely off,
5. Turn off your motors. This is critical, because the motors will hold belt tension unevenly until they are powered off.
6. Re-home the printer,
7. Run the same realtime oscillation of T0 on Y axis at 40hz (or wherever your peak is), you'll notice some of your X activity has returned. This is because you turned off the motors and the toolhead belts were able to balance.
8. Begin tightening the toolhead belts slowly again, until the X activity goes away. It should take a lot less turns this time.
9. Keep repeating this process until you are able to turn motors off, home, and start an oscillation with no X activity left.

After you reach that point, do an input shaper test again and see how you fare. Hopefully you'll have one big Y spike and a little 125hz bump like I do above.

Also doing this got my toolhead belts pretty damn tight. Dunno if I am too tight or not, but the graphs look great so I am rolling with it lol.~~

Hopefully someone finds the above useful, and maybe someone will help me figure out this 125hz peak.

[grim niche]

Thanks for the guide on how you tuned your belts i will try that now. My graphs are not that clean but im in the same boat as you with the 125hz peak. I basically rebuilt the printer 3 times by now and still didnt find the issue. 🫠

[dire laurel]

Hope it helps, no idea if it's the "right" way or if it's too tight on the toolhead belts, but the graph looked so good I decided to risk it 🙂

[grim niche]

Idk if there is a right way but your way got you a better result for sure 🤣 i will try that

But im actually going insane with that 125hz peak 🫠🫠

[wheat trail]

Can you make a video of how belts look after that? Like is it super tight or loose?

[carmine wagon]

Ratrig should release some tension tool data on initial setpoints or good start tensions to allow us to have a decent shot

[dire laurel]

Yes I wish RatRig would. I show my tensions and such, but I worry other people will blindly follow the video. I don't know what I am doing, so everything you see here should be taken with a grain of salt. I don't want people snapping or bending things lol

[grim niche]

Yeah unless you really fucked up during your build all the printers should within a certain range i think

[dire laurel]

But I am pretty happy to post this. 5,000 Accel perims at 250mm/s. 🙂

Need a bit more PA tuning but man I ain't complaining at that speed

[plush vault]

that sounds really usefull. i'll try that - also struggeling with belt tensions and IS graphs in general.

[plush vault]

@dire laurel one question (maybe dumb one): if you solely tune based on Y T0 - how does this affect Y T1 and X in general? or are they basically all aligned to each other after you did the x-belt-tuning with Y T0?

[dire laurel]

That's a good question, you guys may have to experiment and let me know your findings there. Basically I hit a point where I was like "I must get Y better, the others will just have to fall where they will". There's so many variables that I just decided to solve the worst issue.

That said, I did a full shaper test after. My X0 and X1 both looked great and I had a ZV (not MZV) recommendation on those. At work at the moment and can't post them, but it seems correcting Y in this way got X looking pretty good as well in my case lol

It's so difficult to get everything balanced I can't imagine going much further. Anything else you touch causes the X/Y balance to get really wacky fast

One area I would like to play around with is the hybrid tension. You notice I say start at low-mid tension, this was just where I felt they were tight but not too tight. There may be a better place for those to be, but i'm not sure how to determine it without a lot of trial/error.

[plush vault]

yeah i feel that, i'm trying to figure this stuff out since 2 or almost 3 months now - got some current IS graphs from my last try here: #v-core-idex message - upping the x-belt tensions helped (after much hardware-fixing. motor plate alignment and stuff) and also @cosmic heart and others determined that a low to mid y/hybrid-belt-tension seems to help. while others only had success with high belt tensions in general. my guess is - it depends on the machine and especially machine-size. so far for my 300 idex lower y-belt-tension in comparison to the x-belts seems to work better than equal tension on all 4 belts.

[dire laurel]

I would say machine size is going to make a really, really big difference.

Those long belt spans on a 500 get floppy in some frequencies

This was another reason I was hesitant to post a vid plucking my belts, someone will run with that without fully checking

[plush vault]

yeah could be the reason why higher tensions in general work better for the bigger machines - more tension = stiffer belts.

[dire laurel]

Hands down the biggest breakthrough from those steps is turning the motors off and repeating the tuning process. If a good friend of mine hadn't brought that up, I would still be tuning rather than printing

[plush vault]

plucking is absolutely not recommended for idex. maybe just to get the belts in a rough ballpark, but you almost always need measurement equipment. belter, west3d-tension-tool etc.

and yeah turning the motors off and then retry makes sense - lets everything settle in position.

but honestly i'm so frustrated with my machine right now - i have a feeling i'm so close to getting usable graphs but just can't figure out those last few gremlins 🤣 while other just do the ol' "send it" and get great results

[dire laurel]

Yeah especially on X. If you think about it, starting at the tensioner, the side going straight to the motor is much shorter than the side of the loop going to the toolhead. So when you tighten the tensioner, the short side of the loop gets much tighter than the toolhead side. You'd think it would adjust out through the toolhead path of the belt, but it doesn't lol

I toyed with it probably 20 hours in shaper tests/realtime analyzer, I was feeling pretty horrible with my purchase, glad to find at least some path to good results (even if I may be running too tight, we'll see)

[plush vault]

makes sense because the motor is actively forcing the belt to hold in position when idle or pushing/pulling when moving. at least when you tension while under motion it should probably equalize over time? but switching the motors off and re-homing is always a good call when doing belt tension. you could also spot when your tension changes erraticaly or in big steps - that could hint to a motion system issue (binding and stuff).

[dire laurel]

I had to repeat the process five or six times before I could start it and still have X activity gone from the result

Feels like putting new strings on a guitar

[plush vault]

and then when you do Y T1 you get the same result? or for X?

[dire laurel]

I didn't, after I did this on Y0 with T0, my X1/Y1 were really looking good as well so I sent it

Well, it's kinda tricky. You can't really have a significantly different tuning because the belts also keep the gantry square.

So I fixed my main toolhead, and in doing so got the others in line because they had almost the same tensions to keep gantry square.

[plush vault]

hm.. well i'll see what happens. but looking from this angle it makes sense. you tune both x-belts against y T0. and if your y-belts are the same (or close together) then that automatically also applies to T1.

it's a closed system - changing one thing influences all the other things too.

[dire laurel]

my Y1 still had an additional spike, but it seems to be common on most of the graphs I see here

[plush vault]

yeah that 125 Hz spike is an idex mistery. many people have it and no one could figure out what this is yet

but it shouldn't really matter for printing because it's way outside the usual movement range.

[dire laurel]

Nah I mean another inbetween there, I think it might be due to the different position of the X belt on T1

but it was also highly refined after this process, had only Y vibrations

I just ran an 8hr rat pack print so I am sure they've settled and I will need to do a touch up tune, I will post some full graphs here when I get a chance 👍

Would have originally but I was hunting down the 125hz when I made this thread lol

[plush vault]

yeah those random spikes here and there could be all sorts of things. looking at my graphs - those spikes around 50 Hz on my X? yeah i BET that's my electronic enclosure. the top plate with the fan starts rumbling like crazy between 50 and 90 Hz 🤣

[dire laurel]

sec, I got a quick hack for that

I just grabbed some longer M3s and M3 nuts, lifted the lid away

just screwed the bolts in til they stopped turning, then tightened the M3 nuts to the plate

[plush vault]

that's just so beautyful and insane at the same time, macgyver would love it 🤣 guess i'll try that and see how it improves things.

but in the long run i guess i'll just straight up replace that enclosure with something sturdier. like a proper junction box housing or something.

[wheat trail]

straight wall is a bad example for IS, try something with a lot of angles like embossed text

[dire laurel]

So I ran into a snag with the setup last night. Made it about 10hr into printing and had a layer shift in X I believe (was shifted equally in both X and Y). Might be my method of tuning this runs X too tight, haven't had a chance to check. My worry is if it's even possible to get clean shaper results without getting the belt this tight.

[dire laurel]

Ran fine through a 9hr PLA print, this shift was during my first fully enclosed and heat soaked ASA print, so could also be some binding appeared somewhere. Will report back

[cosmic heart]

Could be overheating motors, what was chamber temp?

[dire laurel]

56C~

at least according to T1 which was parked to the side

I hadn't considered that

[cosmic heart]

60c is getting close to pushing it for the factory ratrig setup from what I've been reading.

But i think your motors should be fine... Maybe lol... Is your cooling fan directly over the drivers in your electronics enclosure?

[dire laurel]

Yep

I assumed it was lower than 56C, hotend would be decently close to the bed (though, I guess the motors are too)

Tonight I will loosen the belts off and check for binding while heat soaked. If there's any I will realign rails, and this will give me a chance to try my belt tuning ideas again from scratch

Then I will try a bit cooler

[cosmic heart]

Re-racking wouldn't be a bad idea

Also possible it collided with the print? Especially if using interference style infill

[dire laurel]

It could be. It's the Rat Pack parts and they print them with a 45 degree overhang, so had some slight curling

I'm still new to ASA, so figuring that one out. Haven't had an enclosed machine until now lol

[wheat trail]

shouldn't be, LDO HT which are used for the X and Y are rated for 180C

[cosmic heart]

Was not aware, thank you for the info :)

[dire laurel]

So I found the issue. T1 belt keeper gave way under the tension, so this is definitely too tight. Not sure how to get clean graphs out of Y at this point.

[wooden vessel]

@dire laurel Maybe you should dry your filament more

j/k...lol just trolling and im entirely not useful here

[finite garnet]

Because of these issues and the lack of instructions or any clue on how to fix the prints, I feel like throwing the IDEX out and going back to a hybrid.

[dire laurel]

I feel you man

[finite garnet]

like for my buisness its not worth anymore to try next 2 or more months just to try print something

[main barn]

Im starting to think the same thing. What is the best Y graph you've seen? I wish they atleast gave us a decent goal to shoot for. Not just a good "Luck"

[cosmic heart]

Not saying I have the best Y graph or know everything on tuning an IDEX, but it's possible.
#1324491900052439134 message

Input Shaper graphs are a good troubleshooting tool, but is not the end all be all. These graphs will never be perfect (and if you get them that way, they wont stay that way). Every machine is built differently because each person and their own personal tolerances for assembly is different. Input Shaper just says that you can print at that acceleration and below without having ringing. That's it. You can print above that accel no problem and majority of the time never know you dont have perfect graphs. I've seen some phenomenal prints come out of my machine when it says 3k accel and the graph looks like a mismanaged landfill

TL:DR, benefits from high X tension and slightly lower Y tension. If you target greater than 6k accel in MZV, then you can print the basic profile with NO ringing.

[cosmic heart]

what belt keeper gave out? The toothed one or the weird trapezoid shaped one?

[main barn]

thats the highest Y I've seen I thought someone having 5k was amazing. I really hope RR add IDEX belt tuning to there guide. It says they are trying to craft one.4

[finite garnet]

im done XD i will go back to hybrid on my 500 bc of its size its not worth it to try do it anymore. i have v-core 3 500 i might use some of its component and just build idex v4 300 it will be easer to work with

shorter belts etc.

[wheat trail]

On my way to the mental house with theese belts I found out that despite IS told me to use ~50Hz for mzv the print result was still not good(big dip after corners but no ringing afterwards). Spent some time to adjust the belts while printing ringing tower but doesn't seem to affect. But what is actually helped is to set Y shaper to 30Hz which almost eliminated the dip(tried from 30 to 50 but 30 turned out the best). My goal was to print at 6k acc so I ran all the tests with that. Now I print at 250ms and 6k acc and so far looks good. Belts are now almost equal to each other at around 6.5mm by the BTT tensioner.

[finite garnet]

Go back to hybrid and wait for official instruction is my option i choose

[plush vault]

well.. guess another good tipp is: if your graphs look like crap - check that your electronics box is not adding noise. @dire laurel nice hack with setting off the backplate... i did it with 30 mm stand-offs i had left over. for y i'd say i take it - now just figuring out if i can tune x a bit more.

[main barn]

Any tips / guide to how you got these graphs? They are decent I'd be thrilled.

[plush vault]

mostly fixing stuff step by step - my machine apparently had (and maybe still has) a few "mechanical gremlins". my mounting plates in the back were miss-aligned (had a 0.1 mm gap on the lower plate of the upper hybrid assembly on the right side), that in term caused my gantry to always be a bit racked when i tried to de-rack with the gantry fully pushed to the back. that gap was small - but over the distance (it's a 300 machine) that added up and caused a few degrees of racking back to front. also screws.. how often i tightened every screw i could reach. make sure your XY-joiners are as tight as can be (only exception: the bolts holding the idlers. those are snug - but not over-tight). i greased and de-greased my rails three times. have even replaced my y-rails with older, known-good 400 mm rails from an old printer that worked until the end (de-comissioned hypercube evolution with rail conversion). i worked on this on and off for almost 3 months now.

and also tried a whole bunch of different tipps and tricks from wetson, xulkal and all the others that hunt these perfect shaper graphs. but i guess in the end the best advice is: make sure that your mechanical sub-system is in good shape and maybe try a few test prints before going in too deep. idex apparently can't have perfect shaper graphs just because it's an idex system. if it's not obvious that something is mechanically wrong with your machine or that you have a defect somewhere... well then i must admit it's not worth it overdoing 😄

i will try one or two things now (tightening/loosening idler bolts in the back - mainly on the right side where T1 sits, because i suspect they are a bit looser than on the left where T0 is, then maybe play with the tension of the x-belts a bit more) but then i'll guess i call it quits if it doesn't change much.

[main barn]

Okay, so you have a 300 IDEX that explains why your recommended is so much higher than mine at 500. Man It's so much harder than single Hybrid. I think Im just gonna shoot for the same tension/ good racking and let my IS graphs be what they be. I feel like equal belt tension is the most important.

I just wish RR had a guide like they did with the single head

[plush vault]

yes, for the bigger machines i can't say much apart from that their Hz-values are lower. also their belt tensions. the 300 machines can cope with higher tensions, and i think they also need it because of the shorter belt runs. what was also noted for the smaller machines is that they seem to like it when the Y-belts are on lower tension than the X-belts. with all 4 belts at the same tension i always got worse graphs. lowered the y-belt tensions a bit -> better graphs. for the bigger machines that's totally different.

[dire laurel]

I'd be happy to just drive the X activity out of the Y graph

[plush vault]

and yeah a fully-fledged guide would be nice, but i guess we provided them with so much information in our endeavours that they either compile everything into a big "how to tune idex belts"-guide... or just realised themselves how hard it is to tune these beasts properly.

[plush vault]

i'm not sure if this is even possible because all four belts influence each other. look at my graphs - that peak only goes so high because X and Y add up.

[dire laurel]

It's possible, just need to get X so tight it breaks things lol

[plush vault]

yeah but honestly, having a bit of a physics background, i'd rather have both peaks add up at the same point - that means it's overall a sharper peak and IS can filter it out better.

[dire laurel]

My worry is the X activity is a result of the hybrid belts and toolhead belts not pulling Y in time

Basically the toolhead belt goes to move in Y, but hybrid has either already done so or hasn't done it yet, so it translates to tiny X movement

It makes me wonder if there's a way to adjust the timing of steps between the hybrid and toolhead motors, make this a timing issue rather than a belt tensions issue

[plush vault]

hm i don't think so. you'd hear that - in y all 4 motors push/pull at the same time. if just one would lag behind, your whole movement coordination would break down and then the gantry would bind up. if you have ever miss-configured a corexy-system so that both motors spin in the same direction... well.. it's NOT a nice realisation can't hit that E-stop fast enough.

[dire laurel]

Yeah I am talking ultra minute differences

something that could be absorbed by the small amount of backlash in the system

I guess what I am saying is why does having X ungodly tight result in this graph?

[plush vault]

hm then you'd be in the area of microsteps and that would be something that klipper itself would have to deal with - that's why you have that dreaded "timer too close" error

[plush vault]

over-dampening

[dire laurel]

Basically so tight it can no longer vibrate in X?

[plush vault]

your X is SO TIGHT that it physically can't swing anymore

[dire laurel]

Might be, but my X graphs looked pretty great too

[plush vault]

yeah but that's where you get bearing damage, maybe even motor damage (maybe not so on our double-supported motors) if you really overdo it

or - clamps breaking 😄

if it's so tight that it's physically not possible for the belt to swing anymore... you have very high forces on there. but usually you should see this in the X-graphs - if you go into "over-tight" territory, they should get all weird and crazy with spikes and peaks everywhere.

because then they can't "balance" out any kind of noise in the movement path

[dire laurel]

I still had good definition there. ZV recommendation with 9000+ accel I believe it was, at work at the moment can't check

Obviously not going to run them at that anymore, just seems like a lot of X activity for a Y oscillation test

Maybe difference in belt length too, a lot more backlash in the toolhead belts vs the hybrid belts

just something throwing that timing out I feel

[plush vault]

yeah belt "alignment" is also a big issue on idex, on both loops. just one or two teeth off and that's it, you can't get good graphs.

[dire laurel]

I do feel that could be solved with a design change. Make the toolhead have some type of small length adjustment so you can set tensioners to the same distance, equalize the belts at the toolhead attach points, then do the rest of your tensioning at the tensioners

basically fine tuned length adjustment at the toolhead somehow

it's not so bad on the hybrid belts where you can see how the belt is inserted into the carriage blocks

but trying to do it on the toolheads is a pain

[plush vault]

yeah i remember the old EVA days on the VC3.1 where you had to tension the belts on the backside of the toolhead. it worked, but it wasn't easy to do.

but what also adds insult to injury - that whole 4-belt-system is so finicky. you change a small thing (adjust belt tension a TINY bit - and we speak of not even 1/8th turn on the screws) and you throw all your graphs out of the window 😄 i'm testing a bit, adjusted the idler bolts a bit (make looser/tighter) and T1 Y fell down from MZV to EI, altough MZV would still be doable, looking at the graph

maybe i'll try tomorrow and see what happens if i go lower with x-belt-tension again. bit by bit.

i have a suspicion that i'm a bit too high now.

also went higher and higher, and it did improve things at first, but now those X peaks just won't get any closer. my guess is, i'd need to snug up my bearing stacks a bit more and lower the x tension a bit again.

[main barn]

In your opinion should the belts be tighter on 500 or looser?

Im guessing it should be opposite with the Y as well? Like Y should be tighter than X

[main barn]

Did you get these graphs from a 500 IDEX?

[plush vault]

judging by what i've read here in this discord: looser. it's a bigger machine, the belt runs are longer.. but in the end it's also just trial and error. same thing with "y belts should be looser than x belts" - we had folks here that had good results with this approach, but also people where this didn't work and they had to bring all 4 belts to equal tension or make x looser than y.

it's a big "depents on your machine and the 'quality' of your assembly", so to speak.

plus IF you have a mechanical issue somewhere - you can tune all you want, until you find and fix this issue, you won't get good results. a normal core-xy-system is more forgiving with stuff like slight miss-alignment and so on.

otherwise i wouldn't have taken apart my gantry 3 times and my motor assemblies two 😄

[dire laurel]

Gotta turn motors off between tunings as well

Takes forever

[plush vault]

@dire laurel had a dumb idea now: maybe i'll use the realtime analysis tomorrow (or when i find the time to do it) and tune my belts specifically so that the X- and Y-Peaks line up. basically the opposite from what you suggested. not "kill" the x-influence - but rather add it to anything that Y is doing. and then see what the input shaper says to this.

[dire laurel]

Try it. I did and couldn't affect the peak enough to get alignment, but there's so many combinations I would hardly say I "covered it".

or do you mean heightwise?

[plush vault]

height and/or frequency. i mean, it's "simple" physics. if you have a wave at a certain frequency, you can add or subtract another frequency. you just need the right "phase shift" so to speak. if you have two waves that have the same frequency, but opposite amplitudes, they cancel each other out. if you have the same frequency and the same amplitude (both in the same direction) then they add up.

[dire laurel]

Yeah I thought you meant frequency.

Dunno if it helps, but I did notice that whenever I got X to go down, Y would go up. I had a thought that I would try to get as much activity out of each one so they could combine and generate a higher value altogether, but they seemed to only want to equalize each other. I didn't exhaust this though

[plush vault]

yeah that's the thing with the belts - all 4 work together (or against each other). i think the key here is to find the point where they all swing with the same frequency and amplitude. the point where they all resonate equally.

[dire laurel]

Made it home, here's the T0 X graph that I had to go along with that Y graph at the start of the thread.

[plush vault]

nice graph. but you even see it there: your peaks are all aligned. y is swinging with x, at the same frequency (or roughly the same) - so the combined peak (X+Y+Z) is higher because they all add up.

[dire laurel]

Yeah I agree, but it's at least a single peak, one sec

this is what I was fighting before going gorilla on the X belt

I mostly had single peak on X through all this, Y was being ultra stubborn

[plush vault]

i see. and i had graphs like these on Y when my Y belts were too tight.

once i lowered the tension a bit and went up with X, that went away.

[dire laurel]

I tried all tensions on Y, loose as can be, incremented all the way up to very tight by like 5 degree turns

[plush vault]

interesting. and i guess you checked your mechanics, made sure your plates are aligned, idlers not too loose/too tight and so on.

[dire laurel]

Best I could get with normal tensions was something like this

Yeah I reracked everything, new lube, reassembled the motor stacks with emphasis on alignment, got belts off idler edges, etc

[plush vault]

and you have what kind of machine? 400? 500?

[dire laurel]

500

[plush vault]

so it seems those bigger machines are even more tricky

[dire laurel]

they have really long belts that like to vibrate against the 3030

I would assume the 300/400 don't have this as much

at some tensions the hybrid belts wobble as much as half an inch lol

[plush vault]

hm before i had my plates aligned my X-belts happily vibrated and slapped the extrusion sometimes. also my y-belts vibrated like crazy. i guess it's because of the slight miss-alignment i had.

maybe something is binding slightly somewhere in your machine, what speaks against this is that your power is in 1e4 range. but your graphs look suspiciously similar to mine when i hadn't done the plate re-alignment.

and my gantry was racked slightly, because of this.

[dire laurel]

I even did a bunch of tests with X gantry carriages loosely attached, just in case there was some binding there

but it ended up in worse results, got slop

[plush vault]

yeah with loose bolts everywhere you won't get good graphs. too much vibration from the screws.

[dire laurel]

With belts off I had it pretty butter smooth, and with belts on and correctly mounted (length down to the tooth), gantry sits square on its own

no need to pull it either direction

Assembled with machinist square, etc lol

on a granite surface, best flat spot I had

I think I will just re-belt, get some decent tensions, and roll with it awhile in hopes someone has a breakthrough (or Ratrig releases a tuning guide...)

I also have the Mandala motor plates coming, might tear into that down the road

[plush vault]

well at this point it's just a bit comedic how some of us try all sorts of stuff to find the "holy grail" in idex belt tension 😂 while all the "send it!"-guys also get good results. it's a bit unfair. maybe i should also just gloss over all the IS stuff and print stuff...

[dire laurel]

It's hard when you see someone post some really good graphs

but I question how well they maintain that

[plush vault]

first i just wanted to make sure everything's mechanically sound... then i fell down that rabbit hole

[dire laurel]

yep, it's like heroin except not enjoyable

[plush vault]

3d-printer-belt-tuning-addiction...

[dire laurel]

Got a GT2 belt wrapped around my arm, biting it

injecting that MZV

[plush vault]

dances around the printer grunting "Tiiighteeen... All.. The.. SCREEEWS!"

but in all honesty, it's sometimes frustrating. but on the other hand you always learn something new. when we're done with our machines, i guess we will know them really well. or just sit there and say "i have no idea what i'm doing but i guess it's the right thing?"... yeah.. i'll see what i can come up with with the realtime analysis stuff.

[dire laurel]

I can say I am the guy who actually did tighten shit until it broke, for science

I just really, really hope there's a solution and not "Welp, 500 IDEX just be that way"

[plush vault]

as long as we don't have an official answer, i'd say that could also be just the case. the bigger machines always had their problems and kinks, even in the VC3/3.1 era. that's why i personally always go for the "smaller" sizes - with a 300 i roughly know what i get, mainly because my previous printers also where in that category.

[cosmic heart]

400 idex

[main barn]

I at least wish they gave us some "Shoot for numbers" I decided im goin for 5k in x AND 3k in y If its all square ill be content. I can still print fast, It'll just be haunted by ghosting lol. Which doesent matter for some parts ya know.

[plush vault]

well look at my graphs.. on a 300, Y can easily reach 10k and higher (i've seen people here where they reached 13-15 k on Y) - but X is a real pain to get right.

[main barn]

From what I've read 300 and 500 are totally different beasts to tune. Your smaller size means you can print faster with less vibration

[finite garnet]

Yeah thats why im going back to hybrid on 500

And

It’s easier to do hybrid from idex xD

[boreal rampart]

I’m looking forward to seeing some more official trouble shooting guide for IDEX also.

Because of the long lengths, I have been curious if an additional idler or intermediate tensioner would be beneficial to reduce the slap on the 500 configuration

[plush vault]

@dire laurel ok so i tried what i said a few days ago, testing with realtime analysis and looking at the realtime graphs and stuff... here's a few things i noticed:

• if you test y and your y-belts are off a bit then you get a flat "hump" on y-output
• in my case i think the x-belts where over-tensioned because the x-signal completely "drowned" the y-signal (x-peak/curve was double that of y)

so what i did: i made sure the y-graph is as sharp as it's possible, making sure both y-belts are equal (didn't quite make it in my case, but what gives, i'm close enough). then i brought the x-belts down in tension until their amplitude was equal to y or a bit below. then i did the whole motors off, homing, re-doing etc although i did the second time just to check, everything stayed where it was. well and then i did IS.. with Y i would be perfectly fine with 9k/10k MZV... but for x i'm not sure if it's too much de-tuned now. like we already determined - it's a really close game of balance and fine-tuning.

[dire laurel]

@plush vault what size machine is this again?

[plush vault]

300

[dire laurel]

Interesting results. It's like you can't gain in one area without losing somewhere else

[plush vault]

yep.. but what i can see from those graphs is, that i maybe still have some belt length issues somewhere. T0 Y both graphs are close, while on T1 the X-graph still goes higher, plus the difference in Hz.

on X i'm honestly lost why it's so bad again...

[plush vault]

guess i have to investigate further. try to fix the unequal belt lengths, then test further with realtime analysis until i find a point where all 4 belts and both toolheads are somewhat happy.

maybe another idea i could try, thinking about it: tune the y-belts while running the realtime analysis at a certain frequency and look where the peak is the highest. then you should have "tuned" them to that specific frequency. and then see what happens if you do the same for x...

[dire laurel]

Got everything going again (took a break + installed Orbiter sensors). Doing a little experiment. Tensioning all belts precisely the same (6lb), and generating full graphs. Repeating this process, going up 0.5lb each time. To ensure consistency, between each tension change I turn motors off, re-home, and test tensions again, repeating until they keep precise tensions between motor off commands (makes a big differenece, especially on toolhead belts).

Will post results when I got them, just now up to 7.5lb, going up to 11.5lb, based on a tensions to frequency chart someone made for the VC4 series (will post it later if anyone is interested, can't remember who to credit)

I realize optimum might be different tensions between toolheads and hybrid belts, but that can be tackled later. Just seeing if anything interesting pops out from this extremely controlled test.

[plush vault]

controlled test is good... but how do you determine the force? 6 lb for example is - from what i've read in various guides and on the docs for the diyshift tension gauge - the upper limit for most normal corexy-printers (for vorons it specifically states 3 to 6 lb) and you calibrate that tool (atleast i did) with 3 lbs of weight until it reads 2.1 on its scale. i didn't test what 6 lbs would look like, but my guess is.. 7.5 and surely 11.5 lb are way off scale 😄

but also interested in the results - i guess at this point we can safely say throw everything you know about normal corexy printers - including belt tensions - out of the window on an idex.

[dire laurel]

tg73 came up with a frequencies chart to tension amounts lookup table. Not sure how accurate it is, just stepping through it. If it's in the ballpark it's good enough, mostly give us an idea where things might level out a bit.

[true tundra]

This is my Y graphs right now

6.8mm on belter

This is my X

Don’t really know where to start on Y tbh

[plush vault]

i think i've seen this table but didn't pay much attention to it because everyone said "don't use the plucking method, it's not accurate". and i don't think that IS peak frequencies correlates to the frequency you get by plucking your belts.

[dire laurel]

In my experience, plucking between the toolhead and joiners (where length stays consistent) has given me good results, assuming tensioners were set to same position and belt length is well controlled.

Also there's a lot of bro science around this topic so honestly i'm not taking advice from anyone at this point

Only data

When I pluck, I am using realtime analysis to get the reading. Gantry always sits square when the belts are synced up. I think it could be just as likely the person saying "pluck doesn't work" had a length issue, or didn't motors off between tests, etc, etc, etc. This is so wishy washy you just can't trust anyone lol

I challenge those people who know to post some good results and a guide.

Up to 8lb of results now. So far, the graphs are staying very consistent with not a lot of changes, which tells me the motors off and re-tension til it sits well is a good choice (no wild, completely different results). Makes me believe it's definitely tension differences between toolheads and hybrid belt sets that causes the massive changes.

[plush vault]

true... maybe i'll give this a try again - i'm just a bad plucker, so to speak. whenever i try to pluck i don't get consistent results.

[dire laurel]

I think plucking is garbage if you haven't gotten your tensioners/belt length right, just can't expect it to be right in that case; however, there's a few spots where length is consistent. On X, it's between the homed position and joiner (assuming homed positions are very accurately centered). On hybrids, it would be between the carriage block and the back idler (which doesn't change position like the tensioners), but this table doesn't have that unfortunately.

[plush vault]

so you just try it for x right now?

[dire laurel]

so I am "close", through careful tensioner placement and belt length

nah I am doing both, the whole way, wanting to keep them aligned for this test - so far my graphs aren't changing much, despite all belts increasing 2lb in tension

which I think is good, shows it might be a "figure out the right difference between these two"

[plush vault]

yeah i think a few of us are "close" on potentially finding some way or another to make this whole belt tensioning and IS tuning process somewhat understandable. but i think you are right regarding the tension differences between toolheads that give people problems. unequal tension leads to unequal forces along the gantry axes, those in turn can lead to binding and so on. and every little thing that isn't right, you see in those damn graphs 😄

[dire laurel]

sec, I will give you a peek

6lb

8lb

2lb tension difference across all belts, yet the changes are very minute

shapewise, anyway, some slight changes in strength of vibration, but not a lot of development

[plush vault]

hm.. what is X, what is Y?

[dire laurel]

Top rows are X, bottom rows are Y

left is T0, right is T1

[plush vault]

interesting. and that's a 500?

[dire laurel]

yep

[plush vault]

hm... this is the same phenomena as with my machine. as long as X and Y where equal in tension Y was always somewhat chaotic. going up with tension made it worse, going down made it clearer. and you even see the different peaks in those graphs between X and Y. i'd still argue that it's maybe worth a shot to align all those peaks as close together.

what's also somewhat clear: one toolhead always seems to be a bit worse than the other.

[dire laurel]

Yeah I am seeing higher accel on X as I do this, so providing no weird artifacts appear on X (I doubt it, since I have already run them tight to the breaking point and had great results doing it), I will start walking hybrid down half a lb and note the results there too

I just want to cover the whole "in-sync" spectrum first

[dire laurel]

Experiment 1 complete. Results for keeping the belts equal tension (6lb-11.5lb, according to freq chart):

1. Carefully tuning frequency of each belt to specified values, motors off, and repeating until tensions stabilize resulted in very consistent shaper graphs that change very little between adjustments. For those seeing wacky all over the place results with tuning changes, make sure you don't test until your tension changes have had motors off and been corrected a couple times.
2. As expected, the higher the tightness, the better the performance. At no point along the way was there a sweet spot to stop at.

Now for experiment 2, leaving toolheads at 11.5lb and taking hybrids down 0.5lb per step.

[boreal rampart]

I will have to give this method a try next week. Boss realized what a mistake it was to say print slow as is when the print time said 62hrs for less than 1 kg of material used. 😂

[dire laurel]

Well, only dropped 0.5lb tension on hybrid belts and already seeing a marked difference. Had a Y graph go from around 3.5 up to 4 power spectral density

just getting started on the testing, just interesting initial change

[plush vault]

so that at least means the theory "y should have less tension than x" has some truth in it.

[dire laurel]

going 1lb under, my results swung back the other direction at least for now

so it could be that it needs under/over, and only by a very small amount or maybe an amount that causes resonances to cancel out or some shit

still early in the test, interesting results so far

[plush vault]

but makes sense - the whole "system" is closely coupled. small changes in one belt-"subsystem" (hybrid or x) influence the other and vice versa. if it's a resonance-cancellation/amplification-mode that has to be achived... maybe we could see this in the realtime analysis.

[dire laurel]

lemme paste 3 images right fast, Y1

11.5, both belt systems

11lb hybrid

10.5lb hybrid

Note the power spectral density

[plush vault]

interesting... but i still think that the tension overall seems too high. those graphs are too noisy

[dire laurel]

was the same at 6lb, just 500 IDEX

[plush vault]

makes note to self to never get a bigger machine, or else: insanity

[dire laurel]

lol well, just gonna have to accept the shaper results and print a touch slower. Can print myself a big 500x500 bucket to hold my tears

[plush vault]

😂 but seriously, i think at that size, it's just the sheer mass compared to smaller machines that gets flung around

that causes all this noise

[dire laurel]

whole machine shakes at much lower frequencies - long extrusions that haven't scaled in size evenly, big wobbly 2020 gantry, long ass belts that are still 9mm, huge panels for enclosure, etc

[plush vault]

yeah apart from the electronics panel... my 300 almost stays silent when it's doing it's IS runs... you only feel the sudden rumble in the floor when it hits a resonance peak. and that even in the next room. apart from that you wouldn't even know what it's doing over there next door.

but even they have these strange quirks in idex configuration.

[dire laurel]

Now that I know the graphs go completely clean at break belt tensions, i'm a lot less worried about it

I have lowered my expectations, if I get 4k accel at this size without ringing I will be pretty happy

on a 500, 4k accel isn't too big a deal, most of the shit you're printing has sides so long you still get up to speed most of the time

[plush vault]

yeah that's the other side of the medal - those big machines don't need 10k accel to reach fast speeds. they have the distance to achive the same with lower accels.

what i noticed and what will force me to redo my belt tensions yet again... my tensioners are all over the place, distance wise... so it seems i botched my belt lengths (again...).

[dire laurel]

I saw someone mention running X purely off the rail, in the first layer issue thread

Makes me wonder about making the 2020 on each end stubby, 75mm or some such, just connect a bolt on each end

shave significant mass and probably help with the first layer issue, just depends on if the rail could handle it without deflecting as much

[hard galleon]

Thats how helge runs his X

[dire laurel]

on a 500? lol

[hard galleon]

Not a 500, but cut stubbies on the end

[plush vault]

2 mm difference between the y-tensioners, almost 3 between both x... yeah no, not good.

[hard galleon]

Im using the ti tube

[dire laurel]

Man that's tempting to try, maybe later lol

[hard galleon]

Interesting tests. On my 500 I gave up on perfect graphs and settled with 4k

running 15-20k on everything but outer walls though

[plush vault]

that could lead to z-problems though. the rails by themselves tend to sag quite a bit. i tried that with my old hypercube evolution when i converted that to rails. this thing also just was 300 mm print area, but in the end i slapped a 2020 back in just because the x-rail alone would bow too much.

especially in a heated enclosure

[dire laurel]

lol

Down to 9.5lb now, so far it seems like it either gets slightly better, or slightly worse. Feeling pretty cyclic, like maybe I am overshooting the sweet spot

If that's the case, could explain why some people feel it's "run the hybrid belts much looser" vs "run them tighter", etc

starting to think there may be many small sweet spots nearby and we haven't tuned finely enough to find them

[plush vault]

maybe try smaller decrements. i noticed with my machine that often 1/8 turn on the screws can be too much.

[dire laurel]

I'm not even going that, maybe going 10 degrees

[plush vault]

still.. these belt tensioners are super sensitive, at least in my experience since i started this whole adventure.

[dire laurel]

yes

if it keeps being cyclic like this the whole way down, I am putting the hybrids right back up at 11.5 and finding some peak in realtime analyzer to toy with

with tiny adjustments

you even have to watch out for the set screw on the tensioner

[plush vault]

yeah these set screws are a nightmare to deal with. they can slightly push the arms off-center when you crank them too hard...

[dire laurel]

yep

for a machine so sensitive with belt alignment, the tensioners are kinda underbuilt

[plush vault]

don't understand why even use these - just machine the parts with such tolerances that it's a slip fit. no need for set screws.

so it looks like some kind of afterthought... they coulnd't make the arms and their holders a perfect fit so they just slapped an additional set screw in there to secure it.

[dire laurel]

one of my tensioners was tapped crooked

I had to drill the mount slightly to make room, else it wouldn't go in

[plush vault]

okay? thats bad... i'd have sent rat rig a mail. and gotten a replacement.

[dire laurel]

probably could have, at this point I am just wanting to get this thing online and be able to stop dicking with it for a day

[plush vault]

😂 well i'm dicking around for months at this point...

[dire laurel]

Went down to 8.5, still just back and forth between rising/falling peaks, no shape changes

Gonna call Experiment 2 there, moving on to Experiment 3. 11.5/11.5, and playing with a peak in realtime

[boreal rampart]

The stubby gantry sounds interesting. I think I would much rather look at sourcing some carbon linear bearings though. May have to do that in my free time and model some designs and run some deflection calcs to see what would work for a 500.

[true tundra]

I think I have the same problem lol

One reaches its limits before the other

[main barn]

Correct me if I'm wrong but in order to get rid of the ghosting, don't you just have to print the out perimeter slow?? Then just print the other part like infill etc fast since you can't see them anyway

[dire laurel]

You're not wrong, but another issue creeps in. On the VC4, the motors are pretty big, and printing at slow speeds causes VFA. Gotta print at around 150mm/s+ to make it go away.

So trading ghosting for VFA

and some print speed lol

This whole thread is mostly just chasing a really nice IS graph and MZV shaper model. Even if it doesn't work out, I can likely just apply a slightly less optimal model and get nearly the same results. I'm about at that point 👍

[true tundra]

This is what I’m getting right now

Don’t even know what to do anymore

[true tundra]

This is my X

Don’t really know where this 125hz spike comes from on the Y

[dire laurel]

I have the exact same 125hz problem

searching the discord for 125hz gives all sorts of theories, haven't seen a concrete cause found yet

[plush vault]

to give a small update here: got no time today to do IS/Realtime Analysis tests... but i fixed my belt lengths. they were off on Y and on X. i fixed the belts now so that both tensioner pairs have the same stick out length in between them when the belt tensions are roughly equal. will see how that influences my IS graphs.

[dire laurel]

I slapped the belts to 11.5 both sets, told shaper test to stop at 100, and it gave MZV recommendation for all belts, around 4.5k Accel.

Gonna roll with it a bit, see how it fares

Rat Pack ASA parts

[main barn]

If it works out let us know. I'll pay for new bearings if thats what it takes.

[dire laurel]

11.5 still within gates recommended ranges I think, hopefully not high enough to be smoking bearings lol

[main barn]

from what I've read its the bearings that give not so much the belts

[hard galleon]

Nice! My sweet spot with the belter is 6.45mm which converts to 15.77NM or 11.63Lbs according to their calculator

Voron z belts are for example 20-25NM so Id think we are well within limits for the bearings

[dire laurel]

That's good to know

[boreal rampart]

Z belts don’t move like XY belts though, so higher belt tensions won’t generate the same heat buildup in a z bearing like they would an XY. Also depends on the wrap angle of the belt.

[hard galleon]

True, but voron xy range is 7.5-15NM on *6MM * belts/bearings

[plush vault]

well somehow i managed to make it worse... pushed all 4 belts to roughly 4-5 lbs i'd guess, but i'm wondering if i still have a mechanical issue somewhere. expect for t0 y, all graphs give me the vibe of "some kind of issue there"...

also for my small realtime analysis graph experiment: i couldn't notice any difference when i tried a few different tensions on y (tried to bring the peak up - find the resonance frequency) - maybe it's too slow to accurately show you changes. maybe i did it wrong. what i noticed though is that my peaks "oscillate" periodically. spectral density goes up a bit.. then it comes back down. rinse and repeat. makes it hard to monitor anything.

[dire laurel]

@plush vault you seen @finite garnet 's before/after IDEX to Hybrid conversion graphs in #v-core-4 earlier today?

it's sickening

IDEX just feels like I paid to have a much worse experience lol

[plush vault]

yeah i've seen them 😅 but i'll stick with idex - i specifically bought the machine to do multi-material-printing and stuff

[dire laurel]

I really wonder if IDEX is possible to tune beyond what we've done. When you think about the kinematics of it, moving the toolheads in an X direction requires a brief tension change in the belt in Y direction (due to the positions of the motors and belt routing). In Hybrid the toolhead is pulled by two belts which I suspect cancel some of this effect out.

With IDEX the only reason you get purely X movement is because hybrid belts are helping to hold stuff rigidly, but even then it's not going to remove all backlash

[finite garnet]

it is possible, but the tolerances and margin of error are such that it is hard not to tear your hair out

on 500

and for this, in my opinion, you need to have more knowledge in the field of mechanics and machines

hybrid/idex

[dire laurel]

NSFW

[finite garnet]

almost 2x accel

[dire laurel]

gat damn

[plush vault]

not only on 500 - also on the smaller machines as demonstrated by Xulkal in is videos. i mean... i couldn't even imagine that the vibrations from y could travel to x through the shared bolt and vice versa. in hindsight, it's logical. but then i asked - why was it designed like this? why not truly split both motor assemblies on each side? i mean it's a handbuild kit machine - you can't expect tolerances in the 100s or 1000s from someone hacking that printer together in is backyard workshop. heck you can't even expect that from some manufacturers. yet it seems like they designed the printer like this.

[finite garnet]

that unknown Y on X resonances made me rethink my idex build

[finite garnet]

well..

[plush vault]

in hindsight i must say... i'm not sad that i bought the idex. i don't think about downgrading to hybrid and single toolhead only. but in hindsight i'm often thinking "man, why didn't you wait til 4.1 when they hopefully fixed all those stupid bugs"

[dim river]

i"m quite interested if the motorblocks from mandelaworks would solve this issue tho

[finite garnet]

problem is that there is no official instruction how to tune it

[plush vault]

that's just the cherry on top and no comment from anyone from ratrig regarding all those problems 😄

[dire laurel]

Still docs problems that haven't been addressed for ages too

Dunno what the deal is

[finite garnet]

maybe just maybe you can look for something in vcore 3 IDEX but its little bit diffrent build

problems might be the same

[plush vault]

my guess is they are helplessly overwhelmed - many many VC4 sold, many QC problems with send out kits (defective parts, printed parts with bad quality and so on) and on top they started their "disrupt" professional brand.

too much growth too quickly for a company that's too small and lacks the manpower to pull all this off.

[boreal rampart]

I’m curious if the belts being anchored in plastic parts with possible issues may be contributing to the noise. Tempted to reprint parts on my Bambu and see if that helps, or maybe redesign some parts to have the machine/fab shop at work make me some more rigid components.

Reprint would be the easiest test.

Or maybe I have work reprint them on the old stratasys. Probably cost $100 USD in their proprietary model and support material. 😂

[dire laurel]

Someone brought up the printed parts in the X gantry, but if I recall there's aluminum spacers inside those

The motor stacks is what I would wonder the most about, mine both had pretty good elephant's foot so there's potential for them to be off there. I have the Mandala Roseworks version coming (supposedly today even), but man I don't feel like tackling it yet

probably awhile down the line, gonna try to print on it a bit first, let it break in some

[dire laurel]

Back to the topic at hand, the 125hz peak. For you guys experiencing it, what have you lubed your rails with? Ratrig suggests thin oil, but I am suspecting the rattling is coming from the ball bearings in the carriage, anyone experiencing it with grease?

[grim niche]

I had the same thought and bought SuperLube Oil without PTFE. They run super smooth but no change in my graphs

[true tundra]

Grease will not let the balls roll, instead they will slide, causing friction in only one side and ending up with a bad carriage

Even tho if it was the fix, I’m good with thin oil

[dire laurel]

Any idea why LDO has docs for grease packing then?

https://docs.ldomotors.com/en/guides/rail_grease_guide

https://youtu.be/UYvhYjkBFTY?si=9DxTIdPRcIAQYR-O

Even Hiwin recommending it, according to this guy

Maybe people using the wrong viscosity of grease ran into those problems?

[plush vault]

what i noticed in my trials: with that light spray-on lithium grease, my bearings noticable rattled when doing IS. with a thicker NGLI2 grease i used (only lightly applied) it's better. but i also don't have that 125 Hz peak - but a higher noise floor in general.

[grim niche]

I think im heading the right direction

[plush vault]

ZV on x for both toolheads? i envy you...

[grim niche]

I had it up to like ZV 9800mm/s² at some point but i lost a bit tuning Y

Tbh getting ZV on X wasnt hard and i didnt even pay attention to X my Problem is Y

[dire laurel]

So I have a theory on the 125hz. I think it's the X/Y joiners. Look at this bump, fairly large 125hz presence.

vs this, which was immediately after I tightened the fuck out of the joiner stacks

I am thinking the printed spacers are slightly taller in Z height than the aluminum spacers, allowing them to rattle

will be interesting to see what changes when I slap on the all metal joiners, when they arrive

makes me wonder why the printed spacers are there to begin with, considering there's aluminum spacers inside of them that should suffice (I mean, they did on the motor stacks?)

Might explain why some people have it and some don't, variance in printed part Z height

ah, the printed part is there as an endstop

Here's one of the parts I am talking about. You can see the aluminum spacers nest inside the printed part (and I remember some of these being loose enough they aren't a press fit). If that printed part's Z height is slightly greater than the spacer, the spacer won't be compressed between the aluminum plates.

@fleet tendon - Sorry to drag you into this one, but did you notice any before/after high frequency changes after you installed your all metal joiners?

[fleet tendon]

trying to remember when I stopped seeing the ~125 bump
I think it was reduced when I added more zipties to the toolhead wires and wire loom back to the enclosure

but ya, mine has been gone for a while now

[dire laurel]

I tested pretty hard with my wiring bundle today, even so far as removing the piano wires. The joiner tightened to the moon was the only place I saw a 125hz decrease so far.

I think I am just going to pause until the joiners arrive

[plush vault]

@dire laurel joining in on this, i never had this 125 Hz peak (or it's so weak i don't notice it on my graphs) - but from what i can say assembly-wise, my XY-joiners were spot-on regarding tolerances, and my spacers were a pretty strong press-fit. looking back i think i even needed to press a few of those in with a vice, because it was just too hard by hand.

maybe you are on to something there.

but yeah you could probably live without the plastic parts if it wasn't for the endstop bumper area that is needed (same as why on y you need the bottom part where the nozzle blockers go in - it's also a bumper for the y-endstop. ask me how i know it )

[dire laurel]

Yes I've rammed my shit because of that piece too lol

I'm just pausing until the all metal ones arrive. When I install them we can see if there's a difference, and I will also have the original set out of the machine to examine closely if there is.

I know at least one of mine was so loose around the spacers that the printed part just fell into place

[plush vault]

yeah probably not good - if they are even looser, i could imagine that those spacers themselves could rattle around in there.

[dire laurel]

That's what I think is happening, and despite me cranking down on it there's still not enough compression on the spacer(s). We'll see.

Wouldn't be the first printed part I've found with varied Z height. Measured the motor stack spacer when I went to the all metal ones

That's the same part, just different ends of it

[plush vault]

oof.. that looks like it warped a bit

[dire laurel]

Yeah I had several parts that were questionable like this.

[plush vault]

.2 mm can make a big difference. maybe some day i'll also get those all metal motor mounts

[dire laurel]

I'm happy with them so far. I noticed plucking my belts rings for a lot longer now lol

Anyway gotta run, catch you guys here again when the parts get in

[plush vault]

i hope that mandala does XY-joiners himself sometime in the future... guess then i don't have an excuse anymore to not order the full package 😂 even if it's going to be expensive to ship that to germany.

[boreal rampart]

Interesting. I will have to take a look and see how the joiners are on the one I built. So far have had pretty good results printing at 2.5k. I’m pretty sure I am flow limited by the Polymaker ASA I am using. Haven’t tried a flow limit test, so maybe I could push it harder. The part is big so accel doesn’t really change my print time much.

[trail minnow]

They are in progress with some very interesting features as well. 🙂

[plush vault]

give!

[trail minnow]

I can't give anything just yet. Still working on the design and adding features.

[plush vault]

https://tenor.com/view/hampster-hamster-water-cress-want-gif-8749288

jk take your time 😂 will be an awesome all-around-package

[dire laurel]

@finite garnet still happy you un-idex'd?

[dire laurel]

Fun begins tomorrow...

[rugged veldt]

funssor?

did u pick the green caps?

[dire laurel]

Yeah. Green caps off Amazon. https://www.amazon.com/gp/aw/d/B0D7MTSP8Q

[rugged veldt]

Have you put them on yet?

[dire laurel]

No, just got them in, will post updates later

[rugged veldt]

before u install can u disasssemble them a post a pic with all the parts that are inculded

?

i ordered mine and want to see if i need anything else

[dire laurel]

They come fully assembled as pictured, all I swapped was the colored washers

Installing one now, just slaps right back in place where the old one was, same screws

If you haven't bought yet, keep in mind @trail minnow is designing some that will likely be better

[rugged veldt]

eu citizen here, with customs the order will be like 250 euro+

[dire laurel]

Oof

[rugged veldt]

arent u changing the bearings?

[dire laurel]

Nah, giving these a go they don't seem much different than the RR ones

[plush vault]

yeah those will be expensive, even more so if you take the reworked motor assembly parts on top - but i think it's worth it.

[rugged veldt]

ordered the funssor spacers too

will see how that goes

if u get everthing from mandala it will be with customs like 600 euro

[plush vault]

yeah i'll wait for MRW to finish his stuff and then see how much it would cost me in detail. regarding the chinese parts, i don't know. i've heard that the funssor parts also have tolerance issues sometimes. also i wouldn't expect a future 4.1 upgrade before end of the year, if it's planned.

[rugged veldt]

i have the titube also

worst case i will do some "adjustment"

[plush vault]

😂

[rugged veldt]

this is already not the straightest tube to begin with

[trail minnow]

Unfortunately can't do anything about customs fees.

[rugged veldt]

MAGA isnt helping either XD

[trail minnow]

I don't talk politics. 🙂

[rugged veldt]

im strictly referring to the economic implications regarding goods in-between both economic zones. Hurts everyone 😛

[trail minnow]

Yep

[dire laurel]

I plan to un-IDEX, but before doing that I thought you guys might like to see the before/after on the replacement joiners.

Before

After

before jumping to conclusions that they are very similar, note the power spectral density

@fleet tendon happen to have the STL for the joiner endstop pieces? Had some fun rush for the emergency stop button earlier 🙂

[plush vault]

almost double the PSD - nice. but graph-wise, sadly not that impressive. so maybe the xy-joiners aren't as big of a deal as we thought.

[dire laurel]

Yeah. I am about to disassemble the originals and do some measurements of the printed pieces, etc

[plush vault]

👍 and then you want to un-idex?

[dire laurel]

Yeah I feel like it's a flawed design

[plush vault]

hm.. i'm not sure yet, but it looks like i found the next problem with my machine. can't get T0 and T1 close enough aligned so that there isn't a visible gap in a dual-color print - i did test-squares and this offset-L-piece-thingy, and it looks like my T1 is about 0.5 mm off in X. despite VAOC showing them both bang-on, with good x-offsets (0.04) and so on and even after completely resetting VAOC and endstop-offsets and doing it all again.

my fear now is that it's still not good enough belt wise and/or still has a mechanical issue somewhere, although the numbers speak against this.

and there are no guides on how you would adjust the X/Y alignment of the toolheads. my Z offset is perfect

[dire laurel]

Yep, hopefully it arrives with that IDEX belt tuning guide someday

Did the following:

1. Measured the stock stack thickness plate to plate at each idler, disassembled and took out the plastic pieces, reassembled and measured without the plastic spacers,
2. Measured the aluminum spacers vs the printed parts.

Findings:

1. There was around a 0.1mm difference in thickness of the plate stack between idlers. This was about the same with or without the printed parts in the stack. Close enough I would say margin of error.
2. The printed part I had threading through the 27mm spacer measured 26.9mm, which is what I would expect to see. The printed part threading through the 14mm spacer measured 14.06, so you would need to compress the printed part a bit to get some tension on that spacer.

All the spacers came out freely from the parts without any effort.

So there is a bit of a chance for rattling spacers, especially if your part is taller than the spacers. If someone is reading this in the future and wants to keep using the stock XY joiners, measure your printed part Z height and sand them down to be slightly less than the aluminum spacers.

[plush vault]

hm, and again this ever re-occuring theme with tolerances

[dire laurel]

Yep.

When I installed the new joiners, first thing I did was set all belts to 6lb tension (according to frequency chart I have shared earlier). Noticed the X belts slapping the extrusions in the back, visibly lol

everything is just too tight for no good reason

tightened them back up towards 10 and that went away

[plush vault]

yeah i mean... just watch xulkals rant-video about the design. 0.1 mm here, 0.1 mm there... that stuff adds up. and then you get wonky shaper graphs, slapping belts and all those other fun things we have to deal with - especially with the idex-machines.

they SHOULD have designed it with bigger tolerances in mind... on the other hand i'm asking my self, why hasn't this been such a big issue on the old VC3 and VC3.1 - they are basically the same design regarding the belt path design.

[dire laurel]

My Mandala top plates for the motor stacks should be here tomorrow. So kicking off the unIDEXing then.

Gonna take the spare parts towards some other small build, maybe hawk the alignment cam off

[proper condor]

Since this conversation has been ongoing, I was curious on your guys thoughts of swapping the side and back extrusions for these to eliminate the belt slapping. Installing the quick connectors and attaching the panels would need to be adjusted. Might design/print a couple alignment tools to keep them straight.

[fleet tendon]

don't think it's necessary tbh.
There's ~2.5mm of space from the belt to the PTFE holder, but ~0.65mm of space from the belt to the 3030...Just move the motor mounts forward using a 0.5 or 1.0mm spacer

[dire laurel]

So, got some interesting updates from unIDEXing. First, let me give you guys my last available T0 X and Y graphs. Here they are:

So far I have unIDEX'd, and have the machine running in Hybrid config with the Hybrid belts OFF. This is purely CoreXY results, belts tensioned to 10lb according to frequency chart I have shared before.

This is also FIRST TRY

NOTE: Low accel on Y to be expected, there's no Hybrid belts on.

but my god what a difference

My top plates from Mandala got delayed (not Mandala's fault, USPS being stupid) - should be in on the 18th and I will add the Hybrid belts back in to the equation then.

[proper condor]

What about the y rail 3030s? Been a while since I’ve had my print on and ran belt tests. Thought they got slapped too. Not many options there tho I guess.

[fleet tendon]

Y already has 1mm or slightly more space

[plush vault]

hm, so maybe i'll re-adjust my motor mounts then, i pushed mine all the way back now. what i also noticed: i tried what mikl told me a few days ago in #ratos-development and plucked the belts while in realtime analysis - i got accurate values, my Y-belts seem to be around 21-22 Nm of tension, my X-belts are somewhere between 17 and 19. but i noticed something strange: i can't get a proper "signal" from the X belt segments that run from the XY-joiner to the front tensioner arms. on both sides. in the live view it just produces a broadband mess of a spectrum, reaching from low 20s all the way up to 120-130 Hz. and on my T1 i clearly hear something ring when i do that, but can't pinpoint where it's coming from - it could be the bearing block.

[fleet tendon]

I will say it's not much of an improvement pulling them forward, but I'm on a 300, so you might get different results.

I am partially tempted to go back to hybrid as I haven't really used idex lately. But that's probably more due to my rebuilding more than printing

[plush vault]

i'm also on a 300 😄

and oh well i thought about un-idexing, just have a good, enclosed printer for ABS and stuff - but on the other hand i bought idex specifically to use some multi-material options (like printing petg with pla-support and such stuff). but it just sucks to have problem after problem with this machine. i tried 2-color-prints in PLA this week - but my toolheads won't align properly. although i get them perfectly aligned in VAOC, once i print, T1 is 0.5 mm off in X. and i have no idea how to fix this.

[fleet tendon]

have you don't the box trick across the build plate?

[plush vault]

box trick across the build plate? if you mean print squares/boxes - yes. it's the same everywhere. consistently 0.5 mm off in X

[fleet tendon]

kk

mine drifts based on build plate location

[plush vault]

oof

[fleet tendon]

I think it's belt related, and need to rerun new belts...but man that shit sucks

this would be the 5th time I've had to do that

[plush vault]

yeah i think if it boils down to "oh well you need new X-belts. AGAIN." i'd at this point just say f it and convert back to normal corexy/hybrid... idex is not worth it then if we are basically extended beta testers at this point. this is what it feels like for me. no proper guides, no statements from anyone officially involved. starts to feel really really fishy for me.

and if the printer at least works in hybrid-mode - so be it then.

[dire laurel]

@fleet tendon - regarding pushing the motor stacks out a bit, wouldn't that make the belt go at an ever so slight angle unless you have also shimmed out the tensioner mounts too?

Or are you only shimming like that in Y?

[fleet tendon]

Only shim the y

back belts have 0.65mm of clearance, side belts have 1.15mm of clearance. So I only shimmed the Y to increase the back clearance as I felt the X had enough clearance already

[dire laurel]

Makes sense. Did you see any improvement beyond less belt slapping? I was curious about isolating both directions to reduce feedback between the motor stacks and the vertical extrusion

But I guess there's no way to adjust the XY joiner distance, so that's a bad idea

I'll go ahead and get some feeler gauges on the way to try the Y shim though

[fleet tendon]

It cleaned up a little noise on my input shaper, not massively, but I'll take what I can get

#mandalaroseworks-🇺🇸 message

There's the before and after of my worst toolhead

[dire laurel]

👍

[dire laurel]

Shiny

[carmine wagon]

i am chasing you down a similar path but without going all metal

[carmine wagon]

that was so fast

20 min

[dire laurel]

Yeah they go on easy

Bottom two plates were more involved

[carmine wagon]

i posted in the idex i was UN IDEXing and the general resposnse was "works for me" or "my graphs look great, you just don't know how to tune"

[dire laurel]

Okay, so tonight I got Mandala's top plates on and hooked up the Hybrid belts. Before testing Hybrid, I did a quick sanity check with just CoreXY. Here's those results:

And here's the results with CoreXY+Hybrid:

^ That's first try, have done zero tuning of corexy vs hybrid belt tensions yet.

Pretty stoked that the hybrid belts only introduced that small amount of difference.

[dire laurel]

Tomorrow night or so I will do some tweaking between CoreXY and Hybrid belt tensions, see what I can eke out of that Y axis.

[wooden vessel]

Looks like it even pushed your resonances up on y

[dire laurel]

Yep a bit.

[dire laurel]

A bit more tuning, putting the side panels back on helped clean up Y a lot.

5800 accel, 273mm/s perims (273~ is where volumetric flow capped)

still gotta swap to the coated 0.6 CHT and tweak PA/settings a bit, been so mired in belt tuning and other shit that I have yet to do any slicer tuning really, these settings are robbed from my other machines lol

Filament is Reactor Red HTPLA+ I think, our buddy @wooden vessel makes it.

[wooden vessel]

Yes sir

Fusion Filaments

[ancient ice]

Without idex? I think i need a aluminium plates motormount

[dire laurel]

Yes, unIDEXed. Never got close to these on IDEX, except when running belts at tensions that break things

[proper condor]

Do you guys think IDEX would benefit from 12mm belts to compensate for the loss in stability from unequal belt placement between the toolheads?

[dire laurel]

It's hard to say. Going from IDEX to Hybrid+CoreXY is such a shocking change. It makes me think if the belts were the problem, we'd see similar effects between the two configs

I've seen three cases now (including mine) where unIDEXing arrived at immediate good results. This kinda rules out a lot of the speculation about frame assembly, zipping up umbilicals, etc etc etc. All we did was take a toolhead off and attach another belt to the toolhead that remains

[proper condor]

Hmm ya. Idk, was wondering since the belts are closer to the accelerometer on t0 and further for t1. I haven’t been keeping up much but I thought everyone was having worse graphs on t1. I’d be interested in mirroring the printed parts then attaching the belts respectively on each toolhead to see if that same relationship could be observed.

[dire laurel]

It looks like Ratrig has dropped an updated commissioning guide now too, with a lot more tuning steps

probably good to evaluate those now too (I'd help but, Hybrid+CoreXY bro now lol)

[proper condor]

Nice, I think when I get my 300 I’ll try IDEX but for my 500s, gonna stick with one color till I see a reduction in IDEX posts lol.

[restive turtle]

i see the old one offline, where have they posted the new one?

[dire laurel]

https://docs.ratrig.com/v-core-4-0/commissioning-guide

it's been unified, you gotta click the buttons for your machine config

[restive turtle]

ahh, okay. even still i navigated from the main web page, i think some of their links are still broken

ty

[restive turtle]

i watched your youtube video and really appreciate the time you put into it and the caution you encouraged, but was this an idex print? and setting graphs aside were you getting reasonable prints with idex?

trying to do as much reading as i can before i pull the trigger on my order

[dire laurel]

Hi, this was not an IDEX print. I unIDEX'ed and I am testing Hybrid+CoreXY config. 👍

the graphs directly above that print are Hybrid+CoreXY with a single toolhead

[restive turtle]

ahh

oh okay, did you manage to get any prints off on idex? have any photos or feelings about the results?

[dire laurel]

I did manage to get some decent ones off IDEX, but it was when I was running belts way too tight. Going up in tightness can eventually clean the graphs up, but we're not sure exactly why (it could be dampening in the system from running things too tight).

[restive turtle]

and when they were less tight were the prints crap? i'm prodding you because i'm mostly interested in printing functional parts not pretty things.

[dire laurel]

I had bad print quality, but others have had good quality (but they may be printing slower, etc).

It's hard to say now that they are providing new tuning instructions that I haven't had an opportunity to test personally. It will be interesting to see others go through those new steps, and if they improve anything or not

If you're not too concerned about surface quality, it might be sufficient

[restive turtle]

Okay, cool, I appreciate that feedback. Yeah, the surface quality i couldn't care less about. I'm more interested in dimensional accuracy and durability of the parts (good layer adhesion, etc)

[dire laurel]

Yeah I didn't see many issues on that front, and they have some software skew correction as well. Print quality at speed was my primary want for this machine, so really went into it wanting a clean shaper model and well defined resonance peak (which IDEX doesn't have)

Hybrid+CoreXY definitely has the cleaner graphs. I would ask yourself how much that extra toolhead will mean for you, vs being able to print very fast at acceptable quality. Not sure how fast IDEX can go with the noisy shaper graphs

I would also watch for a few days as others try out the new commissioning steps, maybe they provided the key to tuning these right

[restive turtle]

All great advice, ty. I'm exclusively in it for idex. If I can't have idex i'll probably go with a different company.

[dire laurel]

One thing I will point out to you, based on what you say your needs are, is this: https://discord.com/channels/582187371529764864/1293322335545196655

If the dimensions of the prints in Z are important, you probably want to buy a titanium tube and implement the suggestions you find in that thread.

[proper condor]

Ya, I was mainly interested in IDEX for multi material printing rather than just color. I don’t mind purging but I hope ratrig manages to feed the filament directly from the toolhead rather than all the way from the box. Fully winding it back into the box adds a lot of time. Some helge videos have suggested it’ll be directly on the toolhead but we’ll see.

[dire laurel]

Got the 0.6 CHT in, max flowrate on this filament (HTPLA+) is 30mm³. Got Orca set to do outside perimeter at max speed (316mm/s @ 5800 accel), and slow down on the inside to maintain minimum layer time. Pretty funny to watch it zip around that outside perimeter.

Finished cube, still honing in on proper PA value so some corner bulges.

[main barn]

Did you change out the fan ducts when you Un-IDEXed

[dire laurel]

Yes, swapped the toolhead printed parts. There's a different fan duct and you need to swap the body to have attach points for both belts.

Right now I am having fun with 0.6 bridging settings but other than that been pretty smooth sailing.

[dire laurel]

0.72 single wall extrusion out a 0.6 CHT, really makes the infill pop through and shimmer on transparent filament

[dire laurel]

Little hair here or there because my filament is wet

[boreal rampart]

Looks great. I have no intentions of going to a single head though. Bought IDEX for a reason. I may see if the machine shop at work can make some aluminum components and see if I can get clean up the graphs a little, but it is printing clean enough and fast enough for now.

[dire laurel]

You may be able to hit this quality on IDEX too, not sure. I didn't do that type of work with it, just couldn't get the accels where I wanted

This print was 5800 accel perims and 10k accel elsewhere (may be able to go higher, just started at 10k). Outside perims were 316mm/s (forced), with min layer time slowdown done within the infill if needed.

316mm/s to hit max flow rate for this filament/temp

For this thread, being dedicated to the 125hz issue, I will do a follow up tonight probably. When I unIDEX'd my 125hz issue went away mostly, and now that I have a few hours of prints since that config went in place I need to check if it's still gone or crept back in.

[boreal rampart]

My print qualify looks good but accels are 2200 for prints and 4000 for rapids.

I’m printing long parts so accel isn’t that big of a change. Mostly flow limited right now.

[dire laurel]

I can highly recommend the 0.6 CHT. On this HTPLA+, max flow rate went from 25 to 32 - unless you're using CF filled or something lol

I haven't tried the hardened CHT variants

Bridging can be a pain on 0.6, but blasting the cooling and going ultra slow cleans them up nice

dropped back the flow multiplier to 0.5 as well

[dire laurel]

https://www.youtube.com/watch?v=sxR78WhgLEU I have marked my previous video as unlisted. It's still available in the description of this new video if anyone wants to hear my original gripes, but with Ratrig's recent actions (i.e., redo of the commissioning guide, hopefully more) I feel like it's not being productive beating them down further by leaving that up in the YouTube search.

If they are acting on it (better docs we've seen, hopefully improved printed part QC, etc), then great. If not, I will leave it up to someone else in the future to go into it. At this point I am pretty happy with the machine in Hybrid+CoreXY config, hopefully I can find a use for the spare parts I have from IDEX somewhere else.

[grave plover]

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[cosmic heart]

I watched your previous video, and while I didnt suffer from a lot of the problems you had (which in turn, leads to the issue of QC/consistency)... I appreciate your willingness to make a follow-up and correction. Really good integrity imo :)

[proper condor]

It’s good they are improving, I want them to succeed as it’s a great community and product. But, I’d be lying if I said it was the probably the most frustrating and exhausting purchases I’ve ever made. I was first batch. Ordered less than two hours after presales went live. It was an escalating frustration over the course of 4 months. No need to get into why.

With your situation, I would have felt the same and was on your side. Doesn’t matter if the experts say it doesn’t matter. It was a continuation of a general theme I had felt for months.

Anyways, sorry to jump in on it. I’m happy everything is coming together and would still recommend ratrig over any other machine out there. Can’t wait for them to start rolling out their Disrupt machine. https://www.disruptengineering.com

[finite garnet]

Ahh yes unidexing

[dire laurel]

Been smooth sailing since, glad you posted your original graph else I might not have tried it lol

[finite garnet]

Yeah it was worth it. I belive its not even worth try going idex on 300+ size

Did you make some profile in orca that works?

im still using prusaslicer

[dire laurel]

Yeah I'm using Orca, wasn't a lot to it after following the steps at https://os.ratrig.com/docs/slicers/#orca-slicer

[finite garnet]

had a problem with stock orca setting and i was getting prints that look liked it was printed at 1000 mm/s but in reality was 200 mm/s

[dire laurel]

I had that when I was using the [input_shaper] block on IDEX, before they had the proper method in the commissioning guide.

I think the biggest quality change I made for VC4 was forcing outside perimeters to print full speed, and if minimum layer time isn't hit it slows down on the infill

This is 316mm/s outside perimeters (max flowrate for this filament). It gets you past the VFA these steppers have

[finite garnet]

Clean print

[dire laurel]

That's single wall 0.72 out a 0.6 CHT nozzle

Fast, lots of extrusion overlap for good overhang, pretty interesting profile

If I get some time this afternoon I'll post screenshots of my settings

[dim river]

running idex on a 500 - surely it's not as fast as hybrid only, but 6k on outer walls is sufficient enough - after figuring out some quirks in the beginning and don't overfocusing on graphs everything works fine

[dire laurel]

Here's my 0.72 HTPLA+ settings. There's a lot of settings here that I may have just kept from the starter RR profile or haven't gotten around to yet, so don't judge me too harshly lol. The biggest changes I would look at are these:

1. In Filament profile -> Cooling settings, I have Don't slow down for outer walls selected, along with a min layer time of 6 seconds (might be able to be pushed down a bit, still testing there). With this option on, combined with min layer time, if you are printing a small part it will zip around the outer walls and do all the required slowdown within the part's infill. The only issue with this is portions of the print that are purely outer walls, such as the smokestack on Benchy, might print too fast for cooling to keep up.
2. I use Orca to do max flowrate tests of filament and set that in the filament profile, then I set my print speeds pretty high and just let max flowrate cap things. Don't get stuck on my speed values too much, most of the time they cap around 316mm/s after being sliced.

I had issues running the part cooling fan at 100% with the stock hardened nozzle, filament didn't like to stick to next layer and I had to keep it under 75%. After I swapped to the CHT this problem went away for me, and I run at 100% all the time now.

That Don't slow down for outer walls was huge. Keeps print speed above the VFA range for the VC4 steppers. Things got much cleaner.

Only really matters for small parts I guess, but the machine is fast so this affects a lot of one off prints.

[boreal rampart]

I wonder if the VFA is what I was seeing on the part I am printing. Did a Max flow test and found PolyMaker ASA to start having issues above 36, so I set it to 34 and was running up to 350mm/s on infill and 250mm/s on outside perimeter.