X-Axis movement problem, but it does not seem to be a mechanical issue
I think there seems to be a problem with the driver on the X axis. (like nothing defective, but like the X axis has a slightly different modulation or stepping)
I think this adds to the extrusion problem the MK3 currently experiences. Perhaps a faulty stepping or timing here also got backported to the MK2.5 firmware, which has this problem now, too.
When i unplug both Y and X cables from the board (no avoid damaging the Einsy via back currents from the motors), and move the X carriage or the bed from one end to the other, i have the smoothest axis movement possible. Nothing stutters, nothing has a slip stick effect, you can only feel the motor steps.
Going a step further, and loosening the belts causes the x-carriage and the bed to move from one end to the other with a tip of a cable tie.
Connecting everything again, and powering up the printer and you can feel the full steps on the motors when you push the X and Y loads (x-carriage and bed.)
So far so good.
Printing a single wall cube and here we go:
- Y axis moves smooth and without vibrations, and the layer lines look pretty good and consistent.
- the X axis however, has a slight vibrating sound and moves slightly jerky, and the whole frame vibrates quite a bit, you can feel this with your fingertips. Either on the motor casing, or the whole frame. Everything vibrates slightly. Nothing on the Y axis.
And everything layed down from the extruder while only this axis is working looks weird.
There are no visible layer lines on the Y axis, and some weird banding on the X axis no matter what i exchange on the X or Z axis:
https://imgur.com/a/CzqAehs
I also have this effect when i completely remove the hotend from the X axis, leaving only the bearing holder there. Hotend is on tthe table.
It can't be the bearings, i tried IGUS and have MIsumi currently installed, both do the same.
fsilva on Github has the same issue:
https://github.com/prusa3d/Prusa-Firmware/issues/602
...
@ Brigandier , do you or anybody else notice this as well?
Since i have two self built clones, i'm hesitant to open new tickets for this, and need some confirmation from original Prusa printer users.
Also, i'm going to look at how the X axis is driven, if you have any idea where i could look too it would be helpful.
Re: X-Axis movement problem, but it does not seem to be a mechanical issue
Try lowering the stepper amperage on the X axis? Just a stab in the dark here.
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Re: X-Axis movement problem, but it does not seem to be a mechanical issue
I tried both ways actually.
Stock is M911/912 X16 Y20, and i tried M911/912 X10 Y10 down to X5 Y 5, where the motors just skip
Also increasing the currents to M911/912 X25 Y25 does not help either. Went up to 35 on both axis.
Re: X-Axis movement problem, but it does not seem to be a mechanical issue
I think there seems to be a problem with the driver on the X axis. (like nothing defective, but like the X axis has a slightly different modulation or stepping)
@ Brigandier , do you or anybody else notice this as well?
I just checked my latest cubes- no evidence of any difference between x and y axis... they look identical.
Re: X-Axis movement problem, but it does not seem to be a mechanical issue
Anybody notice that the moire effect is not as evident when printing a 21mm cube, vs a 20mm cube? This might be a hint to some of our issues as well.
Cube on the left is 20mm, the one on the right is 21mm. Same print settings, 40mm/s perimeter speed (I say this because as I increase my perimeter speeds, the moire effect starts to diminish).
Re: X-Axis movement problem, but it does not seem to be a mechanical issue
MK3 owner here from the extrusion issue post as my machine suffers from that as well....Just to share a bit of info about the different x-y movements. I printed a file posted by Chris on the Prusa owners fb page to test print speeds and choose the best for external perimeters. I quickly noticed when I turned the tower the next side at the same speed was not the same. The test runs from 20mm/sec to 90mm/sec. My machine only printed without patterns on both axis at 40mm/sec and then 60mm/s and faster but with a some vertical bands(Linear advance was off in the gcode according to Chris)
Hope this is useful here.
Re: X-Axis movement problem, but it does not seem to be a mechanical issue
@devilhunter84,
Only time I have seen this behavior was when playing around with linearity correction on all axes, vs just E. If linearity correction gets too far off, movement would get rough. Done anything wonky with that in the firmware?
My MK3 Parts: [Bowden] [New Shoes] [TPU Micro Springs]
Re: X-Axis movement problem, but it does not seem to be a mechanical issue
MK3 owner here from the extrusion issue post as my machine suffers from that as well....Just to share a bit of info about the different x-y movements. I printed a file posted by Chris on the Prusa owners fb page to test print speeds and choose the best for external perimeters. I quickly noticed when I turned the tower the next side at the same speed was not the same. The test runs from 20mm/sec to 90mm/sec. My machine only printed without patterns on both axis at 40mm/sec and then 60mm/s and faster but with a some vertical bands(Linear advance was off in the gcode according to Chris)
Hope this is useful here.
Thanks, will try different perimeter speeds then.
@devilhunter84,
Only time I have seen this behavior was when playing around with linearity correction on all axes, vs just E. If linearity correction gets too far off, movement would get rough. Done anything wonky with that in the firmware?
Still using the stock 320mm firmware from you. Kinda close to giving up now on this.
I'm counting way more than two possible errors for extrusion here, with:
- z fadeout disabled
- TMC drivers unoptimized
- linearity problems
- random mosaic patterns
- random fat layers
and so on
I think i'll just build both of my machines to the end to finish 'em up. Then design and build the enclosure for them.
I kind of regret not going for a Duet WiFi/Duet Ethernet, seeming as the hardware and software there is fully baked out
Spent now close to 3500$ for both machines, so what's the price of another 400$ for two Duets...