Very slight systematic waves every about 2mm on the prints

luc

@luc
To assess whether the motors are the cause, I might try setting a different current.
They are currently set at M906 1700.

Are you thinking of trying a print at 1800 or 1600 or less?

Notepad

@o_lampe OO very interesting, I never considered the difference between 19 20 and 21 tooth. Id say start with 21 tooth as bigger pulley = more grip

Notepad

@luc Less current normally means less vibration force. If it works, Try 1200 or 1400

luc

Hello everyone,
I put on the new pulleys (even though the old ones were just to be cleaned) and with the occasion also the new belt and I can't get rid of those vertical marks that seem to be spaced just under 2mm apart.

Does anyone have any ideas?
Thanks

3DPMicro

@luc since the 2mm spacing suggests its related to tooth pitch flip the belt so the teeth aren't engaged, tension to provide enough grip to execute a test print.

o_lampe

@Notepad In my theory, 20 teeth is the worst, since if syncs "perfectly" with the 200 steps/turn torque curve.
21 isn't a prime number, so I'd go for 19 or 23

luc

I was able to find a way to turn the belt temporarily just to make a print.

The cause is not the belt or even the pulleys.

I'm beginning to think it may be the motors:
https://www.omc-stepperonline.com/it/nema-17-bipolare-0-9deg-46ncm-65-1oz-in-2a-2-8v-42x42x48mm-4-fili-lunghezza-d-cut-completa-17hm19-2004s1

What are your thoughts on these motors?

droftarts

@luc The motors seem fine, but it might be an imbalance in how the coils have been wound. What hardware and firmware version are you running? Send M122 and post the response. Also please post your full config.g.

Ian

luc

@droftarts said in Very slight systematic waves every about 2mm on the prints:

@luc The motors seem fine, but it might be an imbalance in how the coils have been wound. What hardware and firmware version are you running? Send M122 and post the response. Also please post your full config.g.

Ian

Here is what is required
Thank you

config.g
M122.txt

droftarts

@luc I can't see anything obvious in your config or M122 that would be causing the issue. You could try using the latest 3.6.0-rc.2 firmware to see if it makes any difference, but I'd think the issue is either the motors as already discussed, or mechanical, ie a bad bearing on the belt run (if it affects all axes, look at the bearings not on the X carriage, as those don't move with Y axis movement). Overtightened belts can also cause issues. Finally, check that you haven't mixed up the belt and pulley types, ie running Gates GT2-2mm belts with 2GT pulleys, as the tooth profile is very slightly different.

Ian

luc

@droftarts
I don't think it could be the firmware but I'll try it last.

All pulleys and bearings looked good but your point about doing it on all faces I could I had to check to rule out the fixed bearings not on X axis was very helpful in fact, since I had them new, I decided to change both bearings and pulleys.

I made a test print afterwards and did not solve it so I think it is useless to disassemble the other 4 X-axis bearings.

I only have one new motor in reserve. I don't know if it is worth doing a test by changing only one motor or is it better to do both together.

Edit
For GT2 or 2GT: With both old motor pulleys and belt and new ones I tried to see conme copied one over the other and I don't seem to have any doubts about that. They look okay to me.

Edit2:
Changed the left engine: Nothing....all the same as before!