Zing laser cutter accuracy

[LukasFreeze]

Gregor and I noticed today that the Epilog Zing laser cutter we are currently using is not accurate enough for some technical parts.

Example measurements with the same Vernier caliper:

• 20 mm part in design = 19.7 mm result in Y direction (factor 1.015)
• 5 mm part in design = 4.75 mm result in X direction (factor 1.053)
• 4.9 mm hole in design = 4.6 mm result (factor 1.085)
• kerf approx. 0.025 mm (changing the line thickness in Visicut did not have an effect)

What definitely sticks out is that there is always a similar amount missing, not a factor (0.35 mm missing, or 0.175 mm per cut).

we already determined that

• inkscape line width doesn't matter
• X or Y orientation produces the same error
• Visicut resolution doesn't matter (tested 200 vs 1000 dpi)
• exact size displayed in Visicut doesn't seem to matter (looked like rounding errors at first)

Any ideas what we might be missing?

[Pakue95]

What did you cut to measure the sizes? Can you cut some paper or engrave something to see if it is not some material-related issue?

[LukasFreeze]

It's independent of materials, we measured an older piece from a few weeks ago and it also had that error (just wasn't noticed due to a much larger scale).

Also note that the hole size and part size both have the same error - if the cause was just material burning away, holes should become bigger while parts become smaller :-/

[Pakue95]

That sounds like there is some backlash in the XY drive of the cutter. Maybe one of the pulleys came a little loose and is causing the loss of the 1/4mm.

[NitramLegov]

Since we will be giving back the Laser tomorrow: Can we close this? ;)

[Pakue95]

Laser is gone, so let's close this.