Input shaper/Belt Test gone bad?

[manic meadow]

started noticing some artifacts on prints after have finally gotta a good input shaper result with Rath's help (or so i thought). Ran good for a while and now im getting these results.

VT 300
Tap
SB with NH PCB
Running drag chains.

Pics on the way!

[manic meadow]

Noise when homing on X axis

[tough mural]

Something going on in toolhead
Do you have tap?

[manic meadow]

yes

I have the CNC Tap from Vitalii3D

[tough mural]

check that your tap magnets are fully engaged. Use a flashlight on the opposite side of the toolhead from the magnet you are looking at.
If you see light then the magnet or screw needs to be adjusted

[manic meadow]

i do i get the ear out of it?

also, cant seem to get this to work correctly

[manic meadow]

Also, i cannot get the top belt the same length as bottom, unless i give the bottom belt ALOT more slack

[tough mural]

Do not use this test it is still beta

Or if you do use this test do not put much weight behind it

[tough mural]

Ping me tomorrow and I will make you a video

That is vitalli correct

[manic meadow]

correct

I'm just hoping i dont have to take the belts completely off 😅

I heard some people say they counted all the teeth on their belts, sounds like an absolute PITA

[manic meadow]

So i mangaged to get the belts the same length on both sides without removing it.

or damn near close

[manic meadow]

@tough mural is the acceptable?

[tough mural]

What is acceptable? I am not sure what the question is

[manic meadow]

about me getting the belts aligned on the left side

or do i need to do something more

[tough mural]

They need to be aligned (same number of teeth) on the left and right side

[manic meadow]

same number of teeth past the belt clamps?

[tough mural]

Yes both those belts should have the same number of teeth past that point

[manic meadow]

Ok, so i have an even number on both sides of the belt now...the new issue im facing is racking (left side farther back than right) but when i loosen tje bolts holding the X gantry to attempt a derack, i get no results...only way i can kinda derack is to tighten the left belt more than thr right

Im sure that isn't an ideal way

does that mean i have stretched belts or incorrect length?

[tough mural]

Please see my videos. I have several on this topic. Sorry I can’t give more info, but holidays demand attention

@late whale if you have the time can you help @manic meadow with his belt induced racking please

[late whale]

You need to check the gantry with a square first. Grab yourself your machinists square or even a plain old plastic set and check that your Y and X are square to each other. It’s highly likely your front belt tensioners are slightly miss aligned from each other causing you to believe you’re square when you probably aren’t.

Check with the square first and your belts tensioned equally and report back 🙂

[manic meadow]

Where exactly do i need to check this at (mechanics isnt my strong suit)

[manic meadow]

Im guessing i need to go off the front of the x and square to Y?

[late whale]

like so:

Hope that makes sense? We're trying to check that the gantry is sqare and de-racked using a square instead of pushing it back and forth to the end stops and front idlers.

[manic meadow]

ok, is it ok to square it off the backers?

[late whale]

Off the extrusions 🙂

[manic meadow]

i have the titanium backers on the back side of mine, guess ill need to take them off?

[late whale]

On the X? Shouldn’t need to. Btw if it’s on the X axis it’s unnecessary and really only adds weight

[manic meadow]

yea, its on the X axis

[late whale]

How did the measurement go?

[manic meadow]

got busy and didnt get to it just yet

[manic meadow]

square seems to look good, just some slight racking on left side

but the belt induced racking is awful,

I pretty much have to have the left belt fully tensioned and the right belt completely let off

[manic meadow]

@tough mural would this mean one belt is too long? if i hate to tension one side way more than the other to fix the belt racking?

[tough mural]

are you switching back and forth when you tighten the belts? Half turn on a, half turn on b, half turn on a, etc.?

[manic meadow]

yes i am

everytime i tension the right belt, it pulls the left side of the gantry back

[tough mural]

try smaller turns, or have you tried that and it doesn't help?

[manic meadow]

ive done 1, half, and quarter turns

[tough mural]

have you checkout any of my videos on this subject?

[tough mural]

can you take a picture of the gap also please

[manic meadow]

I did, i can use the belts to get most of the racking out of it, but like i said, the left tensioner is damn near maxed

[tough mural]

If that is the case you might want to pull the belts tighter when you are belting them

Can you take a picture of the left and right front idlers

[manic meadow]

yea i can later, what state do you want them in? fully loose or what?

[tough mural]

Can you take with the belts fully tensioned

[tough mural]

They look good

[manic meadow]

yea, i got the racking out, my concern was about how much more my left tensioner was out than the right

didnt know if that would have any negative impact

[tough mural]

It shouldn’t

Not sure why they are not even

[manic meadow]

idk, unless i have one belt longer

[tough mural]

I am assuming you belted with both belts the same length, and the same number of teeth on the right side, and the same number of teeth on the left side

The other thing that can happen is belt induced racking. Where you turns are not 100% the same and the minor discrepencies add up

what some will do is have the belts loose move the x-axis to the front of the machine and tighten, using 1/2 turns on alternating sides, till there is tension then move the x-axis to 150mm and then continue tightening to the proper tension

[late whale]

This. Also it’s quite possible your front idlers are not fully aligned to the extrusions if the gantry is square when using a square to measure it but has a gap when pulling to the front.

[manic meadow]

No, i have fewer teeth on right than left, but same number on top and bottom.

[tough mural]

Okay, please check out what @late whale wrote. He also is good at this gantry stuff

[manic meadow]

they appear to be fully against the linear rails with no space to move

[manic meadow]

@tough mural newest belt comparison

[tough mural]

That all looks good.
Can you run vibrations profile, and the print a voron cube please

[manic meadow]

any specific setting i need to run for the profile?

ran the stock settings @tough mural

[tough mural]

Use 100mm/s as int/ext perimeter speed

And 5k or 5.5k as int/ext perimeter accel

Print a voron cube 3 bottom/perimeter, 0 top/infill

Post 4 vertical sides when done please

[manic meadow]

should i run it with our without PA

[tough mural]

Always with. Try setting pa to 0.038

For 0.4 nozzle

[manic meadow]

ok, starting the print now

[tough mural]

Looks good, what I am seeing would be pa and em, do you see anything from the print

[manic meadow]

what looks like maybe z banding?

[tough mural]

That could be a speed or Pa/em issue. Check slicer view for speed issue

[manic meadow]

what exactly would i be looking for?

[tough mural]

you are going to need to look at the speeds in the sliced model (different colors).

[manic meadow]

i dont see any variations in speed

[tough mural]

Do you have slowdown for cooling on, it would be in filament section

[manic meadow]

not sure?

[tough mural]

that looks good.

it may be worth heading over to #slicers_and_print_help to get their feedback on it

[tough mural]

@tulip cave you have any suggestions on the horizontal line shown in the cube picture above

[tulip cave]

PA or EM

Could try external perimeters first too

[manic meadow]

that will cause the z banding like defect on the axis?

[manic meadow]

@tulip cave @tough mural did a new EM/PA tune. Looks alot better, but still not completely happy with the seam, especially on the round features

[tough mural]

cube looks good

[manic meadow]

yes, the only issue i have with it is in the pic that shoes the top, the seam on the round feature is very noticeable. Any solution for that?

[tough mural]

print a full cube with a top and infill and see if it is still an issue

[manic meadow]

here is another print

is that normal?

[tough mural]

is what normal?

[manic meadow]

sorry, the seam on the side of the print

[tough mural]

looks about right to me

[manic meadow]

this angle may show it better