VC4 Idex Belts

[supple frigate]

This is how mine is looking

Take as much Cable ties as you can

[twilit socket]

yeah my lower ties are missing, had to cut them open to get closer with the hot glue gun - but I will clean it up in a bit to see if that helps

[twilit socket]

I really don't think it's the cables tho - I mean I can hear a vibration noise on 57hz with the realtime analysis tool - I just can't find the source - no matter what I touch on the toolhead the rattling stops. At this point I've completely disassembled it and rebuilt it again

[supple frigate]

Maybe anything else makes the noice and not the toolhead itself

[twilit socket]

I had my ears next to every part on this printer, the sound definitely comes from the toolhead xD

But obviously im not sure if that's really the issue of this spike

[supple frigate]

I really really hate it

Everything was good

Then first print

Okay 1 belt was false

A little twist and everything okay again

Second print and t1 x is false

After change it till its mvz again t1 y is false

After change it till its mvz t0 x is false

🤮

[frigid zealot]

sounds like your belts are slipping? maybe?

had that when i initially tightened my y-belts... tried to tune them to a certain frequency (which is - in hindsight - complete bs, but just as a baseline), turned.. frequency rose.. turned more.. frequency dipped down again. i checked the clamps, and sure, belts slipped slowly out. happened on both sides. guess i didn't put them in fully.

[supple frigate]

I checked them now and they are okay

I also printed them out of pa12GF15 because the abs ones are not really good

[frigid zealot]

oh i just meant that as a example - if you have problems with x, it's the toolhead-clamps maybe. they seem to be problematic often, there are stronger ones out there on printables.

the two on the front

[supple frigate]

Ah okay nice
Till now the pa12 ones are great

[twilit socket]

I've once again redid the whole toolhead - I think my spike comes from something else xD

theres no way I build it shitty 5 times

[supple frigate]

🤣 I think so too

[frigid zealot]

and now onto searching for that needle in the literal haystack...

[twilit socket]

i just looked at it, and is there a chance it's caused by the x belt? at about the 50hz range its vibrating A LOT - so much, that it's clearly visible

[deft trout]

that normal

stop obsesing about it

just get it to mzv

then forget about it for like a month

let the belts stretch

[twilit socket]

but 2.9k is garbage

[deft trout]

yes

it is

[twilit socket]

i mean.. i can't leave it like that

[supple frigate]

😂😂

[frigid zealot]

well here we go, my initial IS-graphs for a 300 IDEX... i have a feeling that my y somewhat on the right track, maybe a bit less belt tension? but boy is my x-axis waaaay off and all over the place - or somewhere something is horribly loose 😂

[twilit socket]

I hate you for your y graphs
but your x graph will settle once you have it at the right tension

[frigid zealot]

yeah but honestly my y graphs aren't that hot either. if you look at other's graphs around here, there are better ones.

[twilit socket]

never looked at the graphs for 300 printers to be honest - from my 500 perspective this would be a dream

[frigid zealot]

500 is that tricky to tune?

[supple frigate]

Nice but now I know like @haughty cliff said
The is graph is not the most important thing on an Idex

It is more important that if you make the vaoc that you can get a good result with only 3-4 times of set up the right offset

I have mzv on all axis too but I need 50 times of changing till my offset is right and after safe and go back to set up the offset its false again

[supple frigate]

Hell yeah 😂

[supple frigate]

Do you did the voac already ?

[frigid zealot]

i tried but didn't work out, got some offset error, but i believe that was because of my unscrewed nozzles... wanted to get the belts into a general ballpark and then do all the other calibrations (endstops, vaoc, beacon etc.)

[supple frigate]

Ah okay 👍

[frigid zealot]

i basically tuned my belts via spectroid with the gantry clamped to the front and toolheads in the middle - more or less locked in place. x-belts in the front around 115-120 Hz i believe, y-belts i did around 100. as i said, with y i could live, but no idea what's wrong on x. could be the umbilicals, could be loose bolts somewhere, could be binding, although i don't notice any significant binding when im ove everything around.

[haughty cliff]

spectroid and other sound tuning apps are useless for idex belt tensioning

[frigid zealot]

and that's why i'm redoing it 😄

[twilit socket]

interestingly I left my y belts because I couldn't get them to a good value and tried fixing my bowed bed - at the end of the day my y results were on 7k and mvz - sadly I tried to turn my gantry and now I had to start over again

[frigid zealot]

sad thing is, i'm working from home right now and could do a few tuning runs, but i can't... we have ground works around the house currently (company digging trenches for fiber optics cables, one crew digs and cuts the sidewalks open, others put the cable tube in and then fill and jackhammer everything again) so EVERYTHING here is constatly rumbling and vibrating and so on and i think that would completely throw off any IS tuning...

[twilit socket]

yeah not the best situation for tuning is graphs xD

[frigid zealot]

ok so realtime analysis is magical... letting it run for x+y on T0 gives interesting results... above 40 Hz everything seems fine, peaks follow the set frequency. but on the low end below 40, there seem to be problems... around 30 Hz i hear a clear "ticking" noise from T0 i believe, but no idea how to locate that. around 20 Hz the printer seems to "rumble" and i have harmonic peaks in the output, with the 3rd harmonic (around 60 Hz) having the highest peak.

[frigid zealot]

okay the ticking was the orbiter lever

[frigid zealot]

ok looks like my T0 orbiter is super chatty around 20-40 Hz... everything rattles and ticks.

[twilit socket]

with filament in it?

[frigid zealot]

nope, empty. i haven't printed a single line with this printer yet. still setting up and tuning.

[twilit socket]

I had the same issue, the wheel on the tensioning arm is rattling af - put some filament in it, just far enough, that this wheel touches the filament -> problem solved

[frigid zealot]

yep, same. for a moment i thought a bearing is bust or something, but no, it's just that damn lever arm. if i unscrew it and just open it up it gets better. although that doesn't greatly influence the harmonics.

but okay, i'll insert a piece of filament in both so they are happy 😄

[frigid zealot]

hm.. i gave both extruders a piece of filament, no more rattling, but my X still seems noisy... went ahead and lowered the tension on all 4 belts, readjusted the tension with the gantry in the back (roughly same tension, measured the distance between the motor mounts and the rail carriages), it's much more loose now and quieter, but my x-tension-graph is still crap...

[frigid zealot]

so i've tightened and tuned the x-belts a bit more again, now it looks like this:

defined peaks around 60 Hz from the belts, for the most part aligned (maybe i'll give the left one a tad more tension), no idea what all the other crap is, especially on the right toolhead. could that come from the umbilicals? loose cables?

well maybe it's really just loose cables and stuff, i zip-tied down my loose 4028 wires (first on T0, then on T1) and a few swings in those upper regions (100-130 Hz) are lower. but man if that's the case why these graphs look like this, then i have to plaster both toolheads with zip-ties till nothing's moving there anymore 😂

[frigid zealot]

ok that printer is officially confusing me. didn't change anything relating to belt tension, just zip-tied down cables and the reverse-bowden on T0, didn't change anything on T1 (just as a test to see if it makes a difference) - now i get this:

regarding those graphs, i'd expect them to be flipped... T1 = right, T0 = left - or is it?

anyway, generating IS graphs for X now...

[frigid zealot]

that's more what i expected to see, still in the 1e3 range though.

[oak jetty]

@frigid zealot 1e3 is binding.

Check your belt path

[frigid zealot]

hm, did that, feels clear to me. i honestly can't really "feel" anything binding on x - but y feels a bit sketchy, but also there i don't see anything in the belt path blocking. idlers move, motor pulleys move. could be the rails then.

[oak jetty]

You are binding somewhere you could have a racked gantry.

[twilit socket]

i wouldn't say that 1e3 is always binding - I had that too while not having the right belt tension

[frigid zealot]

okay i did a few quick tests, my left hybrid motor pulley was a bit too low, looks like the belt rubbed there a bit. i made it loose, pushed it up a bit, and locked it again. feels better now moving it by hand, running the next IS. but yeah on X i can't feel anything, mybe it is the belt tension (too loose?)

guess it was that damn pulley 1e4 - still noisy. but maybe that is belt tension now or other loose stuff.

@oak jetty thanks for reminding me to check my belt paths again...

[oak jetty]

No worries.

@twilit socket of course but in 8/10 it can be attributed to it, just because it's very common indicator of such.

[twilit socket]

interesting, didn't know that

[frigid zealot]

also didn't know that, but again learned something. with the tension the belts have right now i thought i should easily reach 1e4 territory, that's why i wondered and strapped everything around the toolheads down with zip-ties. that the y-axis has still so much influence on IDEX didn't come to my mind, but here we are. now i'll play with belt tension a bit and look if i maybe find more things that need a zip tie. also can't quite understand that first "hump" in both graphs around 40 Hz - or does this come from the y-belts? the peak around 60 - easy. x-belts. rest? noise from umbilical, flapping cables and crap 😂

[frigid zealot]

erhm... i guess it's too tight now? 😂

[frigid zealot]

ok last try for today, as i couldn't get anything good trying around just with the x belts, i loosened all the belts and started over. this time with both Ys almost loose (just enough tension so that they don't slip) and X/toolhead-belts with minimal tension. now it's like this.. back in 1e3 terretory, but i guess this time it's not because of binding, but because the belts are too loose. still wondering what all that crap between 50 and 135 is, especially on T1. just wanted to make sure that Y isn't bodging my X results, i assume it was. also tuning IDEX is just a nightmare with tensioning/loosening belts, running a shaper and hoping the graphs come out ok 😂

[frigid zealot]

hm.. looking at my graphs from yesterday again after i watched the issue identification part of "How to Read and Analyze Input Shaper Graphs generated by Klipper" again there are only two possible problems: either wireloom doing stuff or a mechanical issue (broken idler was the example) - how would you find a broken idler? when i move the printer by hand i can't feel anything, there are no strange (for my expectations) noises etc.

[frigid zealot]

hm.. ok the relation between hybrid-y and x/dc is interesting... i did what i said, realigend/checked the rails, then finally caved and printed me a belt-tension-gauge-thingy. with all 4 belts at the same tension (2nd marking from LOW) i get this:

if i lower the tension on the hybrid-belts (to the first marking), i get this:

notice that the first peak gets lower/disappears and the power spectral density flips between toolhead-sensors. so i would think that again it is binding somewhere, but it "jumps" between toolheads depending on the y-belt-tension. my guess would be that maybe all belts together introduce a minimal amount of racking, thus binding the gantry, but just from moving and visually inspecting the gantry i can't confirm that for sure - for me everything looks fine.

[frigid zealot]

well crap, back to square 1... tighter belts, same bs as before:

gantry is squared, i loosened the 8 m3 screws on top of the plates with all belts loose and made sure its properly square. i re-tightened the shoulder bolts holding the idlers, i checked the idlers on the motors, checked all the bolts there etc... at this point i don't know what else i could try. if nobody @here has another idea, i guess the next step will be to disassemble most of the printer again and check every single mechanical piece from idlers, motorpulleys to the motors to the rails. sucks.

[oak jetty]

1e3 you are still most likely binding.

And my bent atm is on the gantry.

Did you push the Gantry back on the motors

While keeping both toolheads in the middle?

#1296131270920900720 message

[haughty cliff]

overtensioned

[oak jetty]

How far do you think he went if he has this noise on all freq?

@haughty cliff

@frigid zealot The issue is that you go very low tension then go up.

Keep always in mind you want the belts in harmony

So all 4 belts basicly have to work together.

If you f up the y belts it will be very apparent in the graphgs

[frigid zealot]

so even if i'm doing x, i also have to tune y? it's not enough to let them loose?

and then when i'm done with x, fine-tune y?

[frigid zealot]

and yeah that's what i did the whole time, i just have the problem that with T0 the beacon usb cable is in the way sometimes. cable-routing on the toolhead is a bit awkward.

[oak jetty]

What do you mean?

[oak jetty]

Well too loose or too strong belts you get wierd graph.

By loose I mean that it doesn't skip, so tight jsut enough

Same belt lenght as well

[oak jetty]

I've never seen the cables routed like that, you usually go like a snake.

I'll show you mine gime a sec

So it goes on the sides.

[frigid zealot]

well i took the shortest possible path... but yeah that... makes much more sense.

so guess my task for this week is redo my cable routing on both printheads and check the length of all belts...

but i fear that my X/DC belts are already a bit too short - when i first set everything up and tensioned the belts the front clamps slipped on both sides. had to fiddle a bit to get enough belt in there to grab onto it. i had already cut it down at this point, but oh well, if i busted my belts i'll order some more.

and @haughty cliff @oak jetty what big of a margin for tension do i have, for a 300 machine? or is that hard to say?

[oak jetty]

By margin you mean hz or?

[frigid zealot]

yeah or tension in general. how low is too low, how much is too much.

[haughty cliff]

you start with equal belt tension, ver low, and then you make input shaoer graphs, then tighten them by a 1/8th turn and retune IS, .......

this pattern you have is typical for overtension on a idex

jsut a half turn is enough sometimes

there is no other way then trial and error

its not transmitteable with words here on the chat

importat is first to find equal tension with loose tenioned belts, then gradually more tenions in tiny steps

[oak jetty]

@frigid zealot Listen to Helge.

Basicly you want equal and harmony on all.

Then go bit by bit on the tension

Y is EXTREMELY sensitive.

Because its far shorter.

So Y 1/8 is a must

If you do it too much you will f it up and then you gotta restart.

[frigid zealot]

and basically slow and steady on all 4 belts whenever i change tension, and IS on Y is then just fine-tuning i guess. fun for weeks 😄 but if you both say that it is like this i hope it will eventually play out. tuning an idex is pretty wild.

[haughty cliff]

tuning an idex is pretty wild.
this isnt a pony hotel here

[frigid zealot]

yeah, thank you @haughty cliff @oak jetty - i just hope that there is no hidden mechanical defect. because after what you said i think all that power spectral density stuff for a normal corexy can go out the window too?

i always interpreted it like that, the higher the number, the "clearer" the resonances are and the better it is for input shaping. if you can't get a clear signal - well then somethings busted in your mechanics.

[oak jetty]

Its not clear cut on the IDEX.

I've seen both good graphs and trash prints and vice versa.

You have to just get decent graphs, and then do test print

If it sucks you f up somewhere

[frigid zealot]

so basically IDEX is trail & error all the way

i wonder if the realtime analysis could help with a rough tuning of the belts and then do the finetuning with IS

[short forge]

For me it's been fun. I'm nearly done. I can't wait for the mandala metal toolhead belt holders though..

[short forge]

I'm crying right now b/c I know what you mean. I'm hoping this last shaper graph for T0 will be below 1% and I can go. print

[frigid zealot]

those are nice. would be so great to have a MRW-reseller here in europe, especially germany. it's not really viable to order anything from mandala because of freight costs, taxes, tariffs etc.. ordering stuff from the US is stupidly expensive right now.

[frigid zealot]

slowly getting somewhere now... guess anything better than 1e4 is almost impossible to achive, so my main goal rn is "get both x-shapers in the 1e4 ballpark and make them agree on MZV"

[frigid zealot]

ok this printer is shitting me, now they both dropped down to 1e3 and 2HUMP_EI... aaand i'm starting over tomorrow

[supple frigate]

Hahaha I just gave up and just look at the result of the print

[frigid zealot]

at least knowing that my belts are somewhat equally tensioned would be nice, a proper working IS is just the cherry on top. but like this it's throwing red hering after red hering towards me. i mean i even had the x-gantry out this week because i thought something was wrong. idler-assemblies not properly inserted to the extrusion or something like that. nothing. i pulled both x/dc-belts out to make sure they are both the same length. they are now. i de-racked the gantry a few times, both with belts out and belts in again. it's as square as can be now. i re-tightened all the bolts and screws i could easily acces.
i just can't wrap my head around why it won't go over 1e4, and most of the time with only one toolhead, or with completely different shaper algorithms on both toolheads IF they both manage 1e4 with veeeery low tension on all belts - that graph was with what, i believe a little bit over the first marking on that belt tensioning tool you can print? so very very loose, just tight enough that nothing slips off of idlers and pulleys. so from my feeling, too loose. then i went up again and here we are, 1e3 and 2HUMP_EI on both heads...

i don't think it's anything mechanical because i checked the idlers when i had the gantry out, they roll smooth. rails - maybe a bit rattling (could be that my lubricant i used is a bit too thick) but not binding or sounding "damaged" (but i must be honest, i never had a damaged rail, so i don't know how that would sound, but i'd imagine it would sound horrible - grinding noises and stuff. i don't have that). and frame-wise, the only thing i did at the very begining was adjust one side a bit with slight taps as my bed mesh showed me a high spot in one corner. that's it.

[stark spear]

i have similar experiences, i dont have a chance to get the left t0-x to more then 500.000, where the t1-x head was something like a poc to get that to over 3.000.000 and with a curve that cant be better, id did hundereds of tension adjustments from flattering low to iron rod like tension and on no point a nearly satisfying curve. the x-mgn rail is a little bit bended in direction of z before installation (maybe this is a reason?) I use linearrail lubricant aswell, that is thicker then oil, but i used that on t1 too. Im clueless. Also also checked als pulleys rebuild the beltholders on toolhead, adjust all perfectly square. All supersmooth, no rattling, just silent

[frigid zealot]

same. thought maybe my belt on T0 is rubbing/binding somewhere, but that's just when it's super loose - with more tension it runs okay again. no idea what to do. experimented again today, got it at one point where T1 had MZV with 1e3 and a good peak, but broad base, while T0 had two huge peaks, 2HUMP and also 1e3... guess i'll just do it really rough, do the rest of the calibration and then wait for a proper detailed guide on how to do belt tension and IS on idex machines. like this it's too much trial and error for my taste.

maybe some guidance on how to do rough tuning/belt tensioning with the realtime analysis tool would be great, as every shaper run takes some time, even if you only do it on x or y alone.

there i noticed that T0 has multiple spikes between 10 and 40 Hz shaking frequency, above 40 you just get a single peak on the frequency you are shaking at, so i think maybe there's the reason why my graphs are so bad, but no idea what that could be. holding the umbilical or cables on the printhead or other stuff around the head doesn't seem to influence those peaks.

[short forge]

I'm having the same not fun experience

I have to change two shims and then I'm going to try new belts as well

[frigid zealot]

ooof. well i re-did the rails (removed old thick grease, added new grease - WD40 specialist white lithium grease) and added the 1mm padding under the bottom steel plates. i have a feeling that this improved things a bit and dropped the noise floor, but i still have to figure out proper belt tension now. and if that isn't working, guess i'll also have another look at my mechanical assembly.

[short forge]

The belt tension has me really fucked up. I'm not motivated to keep working on it

I've been working on it for 3 weeks

I'm about to just go back to hybrid

[frigid zealot]

going to hybrid would suck for me, would mean i'd have to get new belts

and i wanted the idex specifically to do multi-material-stuff 😄 guess i'll just try and get it "as good as it gets", see how it prints, and go from there.

[short forge]

I also do. I’m just tired and frustrated lol. I’ve been at it for 5 hours lol. I’ll try again tomorrow

[frigid zealot]

same... i built the printer in 3-4 weeks. well that was 4 weeks ago...

[stark spear]

what for me gave alot of improvements, was to reinstall the clamps on a "special" way: I Installed them first without the longer screw, that prevent the clamp to get pulled out, and after tightening all and controlled twice, that all tooth are correctly in place, i installed the longer screw

i think, the "problem" comes, when you use grease instead of oil for the rails

after install the clamp this way i get nearly 10times higher values in belt tension-measurements

due to the grease the wagons on the rails are a kind of stiffer (like on a milling machine). So i think they have less chances to generate unwished vibrations

maybe you can print a more advanced clamp to prevent the clamp to bend

[short forge]

Can you please show me what clamp you are talking about / take a picture

What order are you all tightening the belts? Corexy and then hybrid?

[stark spear]

https://github.com/Rat-Rig/RatRig-PrintedParts/blob/main/Toolheads/Rat Rig V-Core 4.0/PP000315-rr_toolhead_vc4_front_clamp_V01_20240327.stl

[stark spear]

Its an idex, so you have to install both, i did the y-first

[short forge]

Are you talking about the y hybrid holders?

[stark spear]

no in my opinion the X-clamp is one of the problems

the STL i linked

the clamp flex to much

and has a damping effect

the clamp flex far more on T0 then on T1

[short forge]

I have aluminium ones from Mandala roseworks.

[stark spear]

nice 🙂 i dont know that this exist, maybe it will help me

[frigid zealot]

i'd like these clamps too, sad thing that you can't get them easily in germany

looks at MRW shop well a set costs 25$... the cheapest shipping option is almost that amount on top (USPS international) 23.69$ - and then i don't even know how much tax/customs i have to pay once they are here, as the EU and esp. germany cancelled any form of free imports for private people if it's under amount of X 😂 i guestimate that i would likely have to pay another 25-30$ just in customs/taxes on top. thats almost 80$ or around 75 € just for two metal clamps

[bright scaffold]

Our site now calculates VAT for under 150 Euros, so you won't get dinged anymore.

[frigid zealot]

so VAT, Taxes and everything is done if i'd order from germany?

[bright scaffold]

Yes, only thing to note is that if you get a bill from Duetch Post, you need to send them a copy of your receipt from my site.

And technically, anywhere in the EU

[frigid zealot]

nice

[short forge]

I wish I had your graphs. I'm struggling with T0

[deft trout]

Follow the guides i posted

[deft trout]

Will work out

[short forge]

you mean the guide from @twin jetty or did you post one yourself?

[deft trout]

His one

[short forge]

When you started from no belt tension. Do you turn each a certain amount or just use the belt meter to get even tension?

[deft trout]

Use the belt meter at 1.3kg

Then adjust from there

[short forge]

I’m going to have to figure out 1.3 kg on my btt belter

[deft trout]

Get some belt and hang 1.3kg water bottle from it

Make the belt like 500mm

[short forge]

Thank you for this. Appreciate it

[frigid zealot]

you can also just use a scrap of belt, that's what i did. the tension shouldn't change much, the force is the same, regardless of belt length

well, it should be long enough to hang it somewhere, sure xD

[short forge]

BTT Belter reading with 1.5kg object is ~6.30mm

I'm going to make a video of this, its pretty damn smart @deft trout , @frigid zealot and @twin jetty

[sour gorge]

what do you think about those graphs? VC4 500 IDEX. I can´t find consistent info about how to properly tune the belts.

[deft trout]

dont use those graphs. they have no relevance for idex. Use is

[sour gorge]

those are my graphs. t0 looks very off. I checked all screws and tightened the wires, but don´t know what else to check. any suggestions? thank you

[sour gorge]

are they good to check belt tension, or really no relevance at all?

[deft trout]

for idex they should not be used at all

follow the video posted earlier

[sour gorge]

does performance mode need to be activated?

[deft trout]

if u have active cooling on your stepper drivers then yes

[short forge]

You may be low tension.

I'll write-up how I tensioned my belts and cleaned the graphs up. Still not perfect but I can print idex now

[dry wave]

so i think my X axis is looking pretty good?

but i am not so sure about my Y axis...

or perhaps my x is kinda tight...

[short forge]

My y is the same

I tensioned everything until mzv on y got down to sub 2%

It's printing well now

You have to make sure to evently tension. make sure to go in 1/8-1/4 turns on all until y improves

[wooden steeple]

when you print the alignment qubes, are they aligned nicely?

[short forge]

Almost aligned but good enough for now

[wooden steeple]

Did you achieve that only through belt tensioning?

[short forge]

@wooden steeple yes and making sure VAOC was good for the x offset. I also had to mess with the endstops for T1. I'm hoping the processess gets easier