Very slight systematic waves every about 2mm on the prints

droftarts

@luc worn, stretched belts could cause the VFA. I think it’s worth holding off doing anything more until you fit those.

Between yours and mine I notice the difference mode stealthChop / mode spreadCycle

The TMC2660 drivers on the Duet 2 only support spreadcycle, no stealthChop.

Ian

luc

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

@luc worn, stretched belts could cause the VFA. I think it’s worth holding off doing anything more until you fit those.
Ian

Yes I know, but in fact that is why I replaced them. Replaced them, however, with new ones that were identical in make and model to the ones that had aged.
I expected some difference in the prints but instead between the old worn and hard belt and the new one I didn't notice any difference. Incredible but so it was.
I will try the Gates as soon as they arrive.

In the meantime I saw Duet 3 6HC and saw that I could use my 6 motors without expansion board (3xZ - 2 x XY + 1 Extruder) but I also noticed the price.

droftarts

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

I will try the Gates as soon as they arrive.

Ah, right, I didn't see the part where you said you had already changed the belts once. See if the Gates belts help.

In the meantime I saw Duet 3 6HC and saw that I could use my 6 motors without expansion board (3xZ - 2 x XY + 1 Extruder) but I also noticed the price.

Unfortunately, that's the cost of UK manufacture, full-compliance testing, board testing post-manufacture, hardware and firmware research and development, sales and marketing, support and documentation. Our competitors don't incur these costs, and largely rely on the community and open source competitors (like Duet3D) to provide R&D, firmware, and support.

Also, changing the controller board is unlikely to help with the VFAs if they are mechanical or electrical in nature.

Ian

droftarts

@luc Just to confirm this is definitely VFAs in the XY system, not the extruder, please watch these two videos, particularly the second one:
https://www.youtube.com/watch?v=dL6u0UwPJOQ
https://www.youtube.com/watch?v=32dTLRNIYmw

Print this object with your normal settings and see if you get the 'woodgrain' effect: https://mihaidesigns.com/inconsistent-extrusion/

If you get the woodgrain effect, then you'll know if the issue is the extruder. If the lines line up, it's something in your X and Y movement.

Ian

luc

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

@luc Just to confirm this is definitely VFAs in the XY system, not the extruder, please watch these two videos, particularly the second one:
https://www.youtube.com/watch?v=dL6u0UwPJOQ
https://www.youtube.com/watch?v=32dTLRNIYmw

Print this object with your normal settings and see if you get the 'woodgrain' effect: https://mihaidesigns.com/inconsistent-extrusion/

If you get the woodgrain effect, then you'll know if the issue is the extruder. If the lines line up, it's something in your X and Y movement.

Ian

Thanks for the information but I had already seen those videos and had filed down the teeth of a gear and made a printout without noticing any difference.

Mine is not wood grain effect.....it's really straight vertical lines...it looks just like VFA.

Consider that in the photo it looks like there are more stripes because of light reflections, but I assure you that the stripes are only vertical.

tas

@luc
Hi @luc,

Are you using Gates pulleys as well? It is very important to have pulleys where the hole is perfectly centered and the perfect diameter. The teeth must be an exact match to the belt tooth pattern as well.

When you place the pulley on the motor driveshaft there should be no play. That way when you tighten the set screws they will not be able to force the pulley off-center.

Best of luck,

Tony.

droftarts

@luc Before going through all of that, did you print a tapered object? Because the objects shown are straight. Another test; do the vertical lines always appear in exactly the same position? If you move the object over 1mm, do the lines move, or do they stay in the same place?

Ian

luc

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

@luc Before going through all of that, did you print a tapered object? Because the objects shown are straight. Another test; do the vertical lines always appear in exactly the same position? If you move the object over 1mm, do the lines move, or do they stay in the same place?

Ian

Here I am, sorry but I was at work.
Printed tapered object? What object could I print? Consider that I notice that effect only on flat surfaces. If I print a cylinder, the result is perfect.

Also consider that if you run your fingers over it, the surface is smooth. Those waves can only be seen against the light.

If you move the object over 1 mm, do the lines move or do they stay in the same place? I'll have to try. If I can tomorrow or as soon as I can.

Phaedrux

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

What object could I print?

A pyramid/cone.

luc

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

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

What object could I print?

A pyramid/cone.

Hi, I know it is bad to leave posts like this without feedback but I have a busy and not so busy time at work. Also, I have decided to redo the whole kinematic system in a different way from the current one, and in the spare time, I have started to design and produce the prototype parts of the new system.
We will catch up later.
Thank you for now!