Posts made by 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!

@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.

@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.

@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
I thank you for the very detailed answer that took up a lot of your time for me.

Let's go step by step:
Cases like this, unfortunately, are dealt with by the exclusion technique. That is, you have to check the many possible causes in a way that excludes them one by one and then examine another possible cause.

The mechanical part is the first to be checked, and from the checks done on the pulleys (4 of 8 were fitted new even though they were perfect for me) it did not produce any changes on the prints. The other four that were not replaced before were disassembled and tested by fixing them to a vise and putting them in tension with a belt and they kept swearing smooth so I think the pulleys are all ok.

The belt was replaced. Upon disassembly the old one was not in good mechanical condition even though they looked ok to the eye. The old ones were hard to the touch, almost wooden, and if they hung down they did not stay taut but tended to curve in places.
The new one, identical in make and model to the old one seems a bit too rubbery to me and I am waiting to receive new Gates brand 9 mm belts.

So, I would like to try Gates belts before venturing into the driver talk, which I study in the meantime.

In the meantime of all this, I also tried using Orca Slicer instead of Prusa Slicer and found no difference.

Instead, I found a VFA test inside Orca Slicer setting it with speeds from 40 to 200 mm/sec and got a print where the difference of the vertical lines, even at 200mm/sec was still visible though slightly less. I mean that in the face of a very large difference in speed the lines varied very little but they were present so now I have a doubt if indeed the driver speech is the cause. That said, considering that the common and unvaried part are the non-Gates belts (even if replaced) perhaps I'd better try these before thinking about anything else.

FYI:
My M569 P0.0 response:
M569 P0.0
Drive 0 runs forwards, active low enable, timing fast, mode spreadCycle, ccr 0x101b4, toff 4, tblank 2, hstart/hend/hdec 3/3/0, pos 0

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

hello, it seems that my problem is identified with the term VFA “Vertical Fine Artifact” and it seems strange to me that from what you read around there is no solution.

What do you guys think about this?

https://ellis3dp.com/Print-Tuning-Guide/articles/troubleshooting/vfas.html

https://www.youtube.com/watch?app=desktop&v=-et5eMyLlUs

https://www.google.com/search? q=VFAs+%28Vertical+Fine+Artifacts&client=firefox-b-d&sca_esv=cc91aa7b516a412e&ei=1egHaKX7EZCN9u8PlJz78AQ&ved=0ahUKEwjluYKEq- yMAxWQhv0HHRTOHk4Q4dUDCBE&uact=5&oq=VFAs+%28Vertical+Fine+Artifacts&gs_lp=Egxnd3Mtd2l6LXNlcnAiHVZGQXMgKFZlcnRpY2FsIEZpbmUgQXJ0aWZhY3RzMgUQIRigAUiMCVAAWABwAHgAkAEAmAGJAaABiQGqAQMwLjG4AQPIAQD4AQL4AQGYAgGgAowBmAMAkgcDMC4xoAe0AbIHAzAuMbgHjAE&sclient=gws- wiz-serp

I have TL smoother that I used on an old printer. Can I try them on the duet 2 wifi or do I risk damaging the board?

@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!

@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

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?

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

@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?

@o_lampe 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:

I tried printing with a 0.3 layer instead of 0.2 and got no change.

This should at least change the distance between the lines?

Your motors are perfectly fine. What we discussed about resonance is a common thing among steppers.

No, almost nothing changes. Maybe very little for the better but the imprint of those vertical waves remains.

@o_lampe
The engines I use on X and Y are these:
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

Cleaning the pulleys slightly improved that effect but did not solve it.
I am waiting for new pulleys that I will install along with a new belt but I don't think I am getting any improvement.

I tried printing with a higher speed without getting any change.

I have tried printing at 45° with no change.

I tried printing with a 0.3 layer instead of 0.2 and got no change.

I tried redoing the PID of the bed and found no change.

By now it has become a war....me against her!

Translated with DeepL.com (free version)

Tried loosening the whole spring of the dual drive extruder without getting any change.

Checked all rollers and pulleys and.....incredible!!!
I have never seen such a thing!!! Belt rubber or maybe dust stuck in the tooth recesses!!!
I can clean it but with the occasion I put two new pulleys.

@o_lampe
Yes, on all sides it is the same.

Yes, it is a dual drive extruder. What can I try in this case? Change it? Change it to which one? (I will have to redesign the whole stand).

I don't see that the spring load tension of the dual drive makes any difference. I tried varying it during printing.

Hi all,
I am trying to eliminate what you see in the photo against the light.. I have done several trials but can't find the cause. The curious thing is that it would appear to have the 2mm pitch of the belt but actually the pitch of the artifact is about 1.7mm. It is an XY core and the movement without the belt is very smooth, the pulleys run smooth and have no play. I had the X linear guide with some play but I changed it.
I print tests at 60mm/sec the outer perimeters.
M566 X900.00 Y900.00 Z60.00 E3000.00
M203 X15000.00 Y15000.00 Z600.00 E6000.00
M201 X1000.00 Y1000.00 Z100.00 E6000.00

I would like to hear your opinion?
Don't look at the angles in the picture it was a PA test.
Thank you

Hello everyone,
I would like another clarification.
Doing the test that DWC proposes by default by clicking on the “Record Motion Profile” button, the parameters it uses for both acceleration and acceleration profile are the ones set in config.g?
So are they M201 for acceleration and M566 for acceleration profile?
Thank you

@dc42
I have a question, in the graph, the Y Amplitude axis, does it indicate the displacement in mm?
(0.018 = 18/100 of a mm?)

Thank you

Other thing, from this further simulation graph it seems to me that MZV intervenes on a larger part on the frequency peaks in my case than ZVD. Have I interpreted this correctly?

Sorry for too many questions but I am trying to understand the logic of its operation.