No one could guess so far

Hi all,
i have the oddest issue with my machine.
- Bodor 1300x900 150W reci. just under a year old.

- circles won't close properly.
https://www.cnczone.com/forums/attac...d=400392&stc=1



- squares with a 0.5mm opening on one side won't close.
https://www.cnczone.com/forums/attac...d=400398&stc=1



- X,Y backlash parameters on RDWorks had to be pushed so high (0.23mm) that it distorts the circles.
https://www.cnczone.com/forums/attac...d=400394&stc=1


- squareness of x,y was checked and adjusted.
https://www.cnczone.com/forums/attac...d=400400&stc=1


- mirrors aligned and tested.
- backlash correction of 0.--0.23mm was tested.

what am i missing?

Under "File Parameters" there is an "Auto Close" setting .... try that. Backlash is technically just for engraving, not cutting.

Quote:

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Originally Posted by TheREV

Under "File Parameters" there is an "Auto Close" setting .... try that. Backlash is technically just for engraving, not cutting.

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Thank you!
I just checked and it was enabled, but a good thing to check.

another test i just ran trying to figure out the backlash the system has on X:
https://www.cnczone.com/forums/attac...d=400458&stc=1

the 50mm center line is engraved first
and then the lines from one side and back to the center and the other side and back to the center.
the numbers are the order of engraving

oddly enough the backlash is only present from left-to-right but not right-to-left.

Is that engraving? It looks like cutting.

Quote:

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Originally Posted by TheREV

Is that engraving? It looks like cutting.

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sorry for the miscommunication,
everything i did and uploaded is vector cutting (just not through).

Ok - so set the backlash back to 0 because it is really only for engraving. Try set the Auto close curves to 0.1 - or even as high as 0.5. If none of that works, you have a gantry straightness issue.

Quote:

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Originally Posted by TheREV

Ok - so set the backlash back to 0 because it is really only for engraving. Try set the Auto close curves to 0.1 - or even as high as 0.5. If none of that works, you have a gantry straightness issue.

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Thanks for the tips!

unfortunately it didn't work, i was able narrow down my issue to backlash in the X (and probably Y) axis.

i checked part of the gantry yesterday against a reference piece, and over 200mm i got <0.02mm deviation. so it might still be off for large pieces but probably good enough for smaller 45mm circles.

https://photos.app.goo.gl/MvnRxUXXNYTadWUV6

the diviations i have are >0.2mm, the most i got pulling/pushing the cutter head is 0.03mm, so i'm not sure i have any substantial backlash in the pulley/belt system.

what's next??

Run test file from origin.
Next move head a bit, say by 2mm in each direction, set new origin and repeat exactly same test.
IF displacement is similar on both cuts that's mean "fault" is related to location.
One from common and possible problem can be belt - was too tight and due this reason it is worn or stretched.

I have a laser that does this in the y-axis if the belts are too tight.

Check for belt tightness and also that all the sprockets are properly attached to the axles. Sometimes the grub screws are not properly tightened.

I too started experiencing some distortion in cuts and scans when I downloaded the file first. I stopped using the Download button and now I only hit Start once I setup layers/speeds/power.

My Chinese laser had the same problems. After wasting an enormous amount of time attempting to fix them, I gave up and sold it...
These problems are typical for all gantry machines and present a major challenge to the companies designing and building them.
There are a lot of components that could contribute to such errors. Solving them requires excellent quality control on both - components and assembly and they are also a major driver for the companies to write their own software.

Dealing with these errors should not be the responsibility of the user! So in response to "No one could guess so far" I have 3 guesses:

1. The manufacturer didn't test the machine before shipping it.
2. They tested it but did nothing to fix it.
3. Tested it and decided these errors are in the acceptable deviation range.

Since the machine is made by Bodor I suspect it is the latter.

You've made the same mistakes I've made - you ordered the machine from the wrong place/company and did not request these test to be performed and the results sent to you prior to making the final payment.
The major lesson for me was - the majority of the Chinese companies don't care about prestige or quality and will make everything possible to push some garbage to you especially if they feel you are shopping by just comparing prices and "features".

Hello sir, did you solve the problems?