Consistent ripples on prints

Agniusm

So getting genuine duet maestro i can legitimately pursue my quest in finding an answer to my initial question.
For those skeptical:

Just made a square print on 2 machines, one with genuine duet, another on clone duet. Red is genuine, black - cloned.
I can say that genuine duet introduced som other pattern that you can see on X axis but you can see that ripples are present on both boards so the issue is not with duet being genuine or not as i have speculated earlier.
X axis:

Y axis:

Any insight @dc42 can provide?

Phaedrux

@agniusm kinda looks like belt tooth pattern. Does it match the pitch of your belts?

Agniusm

@phaedrux It does not match and i have eliminated belts, pulleys, frame resonance from equation by swapping components, even motion system (Linear rail to stock POM wheels). Also acceleration and jerk are quiet low.

dc42

What type of extruder do you have, what microstepping do you use on it, and what its its steps/mm?

Agniusm

@dc42 Titan extruder 16 microstepping, interpolation on, 412 steps, extruder tuned to extrude requested amount.
I am waiting for different extruder to test, but when i think back, i had no ripples with malian or creality stock. I will look if i have a sample photo from long ago.

P.S. These are printed with 32 microstepping on all axis red sample and 64 on black.

Agniusm

Few possibilities:
Could it be low quality stock psu?
0.9 motor has these almost gone but its tested with small pancake motor(e3d titan aero supplied) with speed reduced to 60%.
Options what else could be causing this?

Should mention that 2 systems(genuine and clone) are identical in hardware and software with same sliced file being used.

3dmntbighker

Regardless of the "emotional" aspects of this discussion I think it's probably very interesting to an Ender owner at the very least. And sounds like something useful will come out of all the work Agniusm is doing. Planning to invest in 12 printers, it's understandable someone might want to try to plan and budget without too many surprises at the end. If I were in that position it's quite possible I might buy clone boards until the revenue allowed me to replace them with genuine. Try to see it from his perspective. My CoreXY has a LOT more resonance than my Ender BTW. At least audible.

Agniusm

Well said. Thank you for being openminded.

Agniusm

On genuine duet board there are C shaped artifacts that you might not see in photos clearly, 2 at the very right side are more visible (red sample) on x axis photo (still it might be caused by minuscule upobservable differences in machines) .
Somehow i lean towards motor incompatibility to duet. Blind guess but those motors are not made equal.

3dmntbighker

@agniusm said in Consistent ripples on prints:

On genuine duet board there are C shaped artifacts that you might not see in photos clearly, 2 at the very right side are more visible (red sample) on x axis photo (still it might be caused by minuscule upobservable differences in machines) .
Somehow i lean towards motor incompatibility to duet. Blind guess but those motors are not made equal.

Yeah, were I in your position I might order a similar stepper that is "supposed" to be a bit better quality and try it. It won't break the bank.

Agniusm

I have ordered couole of these motors: https://www.omc-stepperonline.com/nema-17-stepper-motor/nema-17-bipolar-09deg-44ncm-623ozin-168a-28v-42x42x47mm-4-wires-17hm19-1684s.html?mfp=149-step-angle[0.9]
Are they OK? Just to remind, for 24V system

Agniusm

I have been contacted by a member with the same issue on completly stock unit. I can strike out extruder now without even bothering testing it.
Motors shoukd be next week but i am off with kids to rehabilitation center so next weekend maybe.

hussainsail2002

@agniusm Hi,

Any update on this ?

Agniusm

@hussainsail2002 Yes, i have swapped for 0.9 degree stepper motors and the problem is gone to a minimum. The ripples do not feel physically anymore

robm

I think this is somehow a weakness of the cartesian / 'i3' design. I go back to fighting it now and then, but don't see it on my delta or the one print I've done on my new-to-me corexy.

Agniusm

@robm It must be. On other designs both x and y are more or less weight balanced and the print stays put.

hussainsail2002

@agniusm Thanks I had the rippling on my MKS board , when I changed to duet it got eliminated.

Any Idea what the reason behind this could be ?

nophead

@agniusm Did the spacing change (assuming you can still see a lesser effect)?

Agniusm

@nophead Its very hard to see, basically impossible. i will see if i have old sample to get you photo comparison
P.S. Black with 1.8 motor, clear with 0.9 motor if you can spot the difference
alt text

nophead

Black shiny plastic is always the worst for showing defects in my experience, so comparing it with clear is always going to be difficult and anything clear or white is hard to photograph with detail.