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Re: cutting circles with new linear bearing
Posted: Thu May 13, 2021
by Toby Hope
Dave Vigness wrote: Thu May 13, 2021
I'm not seeing any rise / fall in the belt itself. I can see a bit in the outside flange, but that wouldn't affect the belt position. Or am I just not seeing the belt movement?
thanks that’s a good point, i’ll check the pulley with the callipers and see if the flange is concentric with the surface
Re: cutting circles with new linear bearing
Posted: Thu May 13, 2021
by Pete Cyr
I can’t see and eccentricity in the rotation of that pulley when rotating.
Re: cutting circles with new linear bearing
Posted: Thu May 13, 2021
by Toby Hope
Pete Cyr wrote: Thu May 13, 2021
I can’t see and eccentricity in the rotation of that pulley when rotating.
and if there was i can’t see how it would produce the error in getting, so might be non issue but i want to investigate every option just incase

Re: cutting circles with new linear bearing
Posted: Thu May 13, 2021
by Jeffrey Aley
Toby Hope wrote: Tue May 11, 2021
Hi all,
i replaced my linear x axis bearing as there was wobble on the head, new one has no slack which is great, but it is slightly stiffer running when moved manually.
i started cutting some test circles which were awful, tightens the belt tension and they have got a lot better.
trouble is i don’t want to over tighten and with a couple of half turns tightening i can seem to get an improvement on the flat spot on the circle .
i have checked the gears are tight on the motors, any other ideas ?
pic shows the flat/ skew across the horizontal diameter indicting the x axis isn’t moving as it should (i think)
the latest circle after tightening has the fish next to it you can see before tightening above the circles were much worse
thanks in advance !
9D88C5DA-02AD-440C-8FB0-9688CFF4A090.jpeg
This image appears totally garbled to me (something wrong with the .jpeg). Does it appear garbled to anyone else? Could this be a problem with the move of the RDWorksLab forum to a new server?
Here's a screencap of what I see:
Clipboard01.jpg
Re: cutting circles with new linear bearing
Posted: Thu May 13, 2021
by Toby Hope
blimey that’s not right, i’ll see if it still does it if i attach again
24E5CF5F-596A-4DFE-A4A6-A3067A4ABD1C.jpeg
Re: cutting circles with new linear bearing
Posted: Thu May 13, 2021
by Dave Vigness
At first glance they seem oblong vertically. That would be an X and Y re-calibration if it's consistent across the machine cutting bed. Get out a big piece of old wrapping paper and do your test.
Re: cutting circles with new linear bearing
Posted: Fri May 14, 2021
by Toby Hope
Dave Vigness wrote: Thu May 13, 2021
At first glance they seem oblong vertically. That would be an X and Y re-calibration if it's consistent across the machine cutting bed. Get out a big piece of old wrapping paper and do your test.
that might be just the wise angle phone lens, ive calibrated the xy and they’re spot in. i wouldn’t be too concerned about an oblong circle if it was smooth, it’s the tiny kink which follows down stream of the direction if cut . as if it’s got some slack when changing direction.
i have done the scan backlash compensation and sadly it doesn’t seem to have any effect on the cut process. but i have my scan dialled in which is great!
here’s a pic of a couple of targets with infill hopefully making it a bit clearer to see the discrepancy.
14B69323-D696-4DA0-9443-1D2F3BF484A6.jpeg
Re: cutting circles with new linear bearing
Posted: Fri May 14, 2021
by Jeffrey Aley
Toby Hope wrote: Fri May 14, 2021
Dave Vigness wrote: Thu May 13, 2021
At first glance they seem oblong vertically. That would be an X and Y re-calibration if it's consistent across the machine cutting bed. Get out a big piece of old wrapping paper and do your test.
that might be just the wise angle phone lens, ive calibrated the xy and they’re spot in. i wouldn’t be too concerned about an oblong circle if it was smooth, it’s the tiny kink which follows down stream of the direction if cut . as if it’s got some slack when changing direction.
i have done the scan backlash compensation and sadly it doesn’t seem to have any effect on the cut process. but i have my scan dialled in which is great!
here’s a pic of a couple of targets with infill hopefully making it a bit clearer to see the discrepancy.14B69323-D696-4DA0-9443-1D2F3BF484A6.jpeg
The circles show classic mechanical backlash. The backlash calibration is shown here:
Screenshot 2021-05-14 080441.jpg
I forget if you also need to turn on the "backlash reapy optim", which is a typo for "backlash repay optim", where "repay" is Chinglish for "compensation", so this translates to "backlash compensation optimization". It is shown here:
Backlash.jpg
AFTER you adjust the mechanical backlash, THEN you'll need to (re-) adjust the power supply timing. We mistakenly consider this a "scan backlash adjustment". It's really an adjustment for the delay in the power supply (it does not turn on instantly).
This file is recommended for calibrating the backlash - it draws several rows of circles, and the start point of each circle is different, allowing you to see both X and Y backlash issues. I believe ATK Laser is no longer around (but am happy to be corrected).
BACKLASH TESTFILE ATKLASER.rld
Re: cutting circles with new linear bearing
Posted: Fri May 14, 2021
by Toby Hope
Jeffrey Aley wrote: Fri May 14, 2021
Toby Hope wrote: Fri May 14, 2021
that might be just the wise angle phone lens, ive calibrated the xy and they’re spot in. i wouldn’t be too concerned about an oblong circle if it was smooth, it’s the tiny kink which follows down stream of the direction if cut . as if it’s got some slack when changing direction.
i have done the scan backlash compensation and sadly it doesn’t seem to have any effect on the cut process. but i have my scan dialled in which is great!
here’s a pic of a couple of targets with infill hopefully making it a bit clearer to see the discrepancy.14B69323-D696-4DA0-9443-1D2F3BF484A6.jpeg
The circles show classic mechanical backlash. The backlash calibration is shown here:
Screenshot 2021-05-14 080441.jpg
I forget if you also need to turn on the "backlash reapy optim", which is a typo for "backlash repay optim", where "repay" is Chinglish for "compensation", so this translates to "backlash compensation optimization". It is shown here:
Backlash.jpg
AFTER you adjust the mechanical backlash, THEN you'll need to (re-) adjust the power supply timing. We mistakenly consider this a "scan backlash adjustment". It's really an adjustment for the delay in the power supply (it does not turn on instantly).
This file is recommended for calibrating the backlash - it draws several rows of circles, and the start point of each circle is different, allowing you to see both X and Y backlash issues. I believe ATK Laser is no longer around (but am happy to be corrected).
BACKLASH TESTFILE ATKLASER.rld
excellent! thank you this gives me some hope, will look into it
Re: cutting circles with new linear bearing
Posted: Fri May 14, 2021
by Toby Hope
Jeffrey Aley wrote: Fri May 14, 2021
Toby Hope wrote: Fri May 14, 2021
that might be just the wise angle phone lens, ive calibrated the xy and they’re spot in. i wouldn’t be too concerned about an oblong circle if it was smooth, it’s the tiny kink which follows down stream of the direction if cut . as if it’s got some slack when changing direction.
i have done the scan backlash compensation and sadly it doesn’t seem to have any effect on the cut process. but i have my scan dialled in which is great!
here’s a pic of a couple of targets with infill hopefully making it a bit clearer to see the discrepancy.14B69323-D696-4DA0-9443-1D2F3BF484A6.jpeg
The circles show classic mechanical backlash. The backlash calibration is shown here:
Screenshot 2021-05-14 080441.jpg
I forget if you also need to turn on the "backlash reapy optim", which is a typo for "backlash repay optim", where "repay" is Chinglish for "compensation", so this translates to "backlash compensation optimization". It is shown here:
Backlash.jpg
AFTER you adjust the mechanical backlash, THEN you'll need to (re-) adjust the power supply timing. We mistakenly consider this a "scan backlash adjustment". It's really an adjustment for the delay in the power supply (it does not turn on instantly).
This file is recommended for calibrating the backlash - it draws several rows of circles, and the start point of each circle is different, allowing you to see both X and Y backlash issues. I believe ATK Laser is no longer around (but am happy to be corrected).
BACKLASH TESTFILE ATKLASER.rld
I THINK THAT WAS IT!!!!! thanks so much Jeffrey, I could kiss you! but obviously not as not covid safe, but I was proper struggling to find the answer! this makes sense as tighter bearing putting more load on so increasing backlash.
All I did was change the x backlash to 0.15 after creeping up on it, the target on the right has the 0.15 adjustment.. the only thing I'm stuck on now is if I need to adjust the power timing? as no idea how to do that, and if this has it sorted do I need to adjust the power timing?
Screenshot 2021-05-14 at 17.06.50.png
Thanks again!!