Something seriously wrong with my machine

[sweet meadow]

After enclosing my VC3.1 300 and changing all parts to ABS - this is the best I can get after think ~100 attempts to tune/measure belts
Any ideas what is wrong and how to fix?

[ruby pine]

125 is something loose, as for the graphs, looks like tension on upper is too high. I have never gotten anything worst than MZV suggestion . I would check that the whole gantry moves freely too.

[sweet meadow]

My printer probably damned. Or I'm damned. Maybe I should sell it and live normal life, I don't know. This is the best I can get after another full reassemble of motion system with change of XY joiners, total checking of everything, etc... just does not work no matter what I'm doing.

[ruby pine]

I think your overtightened. Put the gantry at 250,250 and the belts should flex a bit if you press them. If they don't your tight. Also I would try a tool. Like from thinvgverse to get you half way there

[sweet meadow]

I set initial belts preload via tone method (with spectroid app) and tried 60 / 75 / 90 hz - no big difference, graphs look like shit anyway

[steep gust]

does it print really unusably badly?

[sweet meadow]

Not, but you could not get good speed/acceleration which does not really make sense for so expensive printer 😉

[steep gust]

ok interesting, I may be having the same issue

I also get belt skips whenever I try to go past 15k accel

[ruby pine]

Just from what I see the amplitude on the frequency from the smaller ones is around 8k.
I have a vcore 500 and I do get the 1e^6 around 1.2

So I think your overtighting

[sweet meadow]

I... just don't understant.

FMMM mod + Metal XY joiners

Home come I get so bad results literally no matter what...

[steep gust]

could this be related to the mounting of the sensor or some other interference related effect? Do prints really obviously reflect this?

[slender dome]

I think you should check your sensor as well

[sweet meadow]

Yeah, also think that might be the case. In my case it is ADXL on EBB42, so it is quite far from nozzle and the mount itself not very rigid

Results after changing belts to Gates

[sweet meadow]

Not sure why I'm still sending pictures here 😉

After another set of adjustments here and there and significantly lower tension (~ 60 Hz on Spectroid)

[small seal]

post pictures with the belts, and the corners where the belts ride the pulleys/idlers, should be belt dust everywhere. they are rubbing somewhere

[sweet meadow]

Belts definitely not everywhere in the center of pulleys/bearings, unfortunately all attempts to make them perfectly centered failed, I do not believe this is even possible, they moving a little up and down anyways. What I see - it does not cause damage to belts, all sides of belts are fine.

[sweet meadow]

I posted photo of belts "dust" here - #general message - but it was everywhere, all places, I assume those are just new belts, after cleaning I don't see this anymore

[sweet meadow]

Okay, this is fixed

[austere grotto]

And what did you do to fix it?

[sweet meadow]

Hehe, new printer basically 🙂 Full reassemble with more stiff corner brackets where possible, shoulder bolts, lightweight X gantry and (damn it) new toolhead

[austere grotto]

which toolhead?

[sweet meadow]

RatRig

[ruby pine]

Noice, I was in the same boat. I switched to dual rail mgn9 , grantryless. VZ CNC printhead, and BRS engineering m2 tensioner and boom. Fixed. 😂

Im in the process of installing all metal brackets too , I think the Eva is too complex, my mgn9 rails are also preloaded. Additionally moving the tensioner eliminated more screws.

[sweet meadow]

Yes, unfortunately, this what you have to do with stock config to make it usable...

[sweet meadow]

There is new type - https://www.aliexpress.com/item/1005006198538785.html - might be more lightweight. I won't be trying, too much upgrades already 😉