[HELP] The result is distorded

[Nalofox]

Hi Everybody,

I'm Nathan, an automatician and I'm here to get help on a problem with a custom laser engraver.

I built a laser engraver to make customized 3 by 3 round stainless steel water bottles (with 3 lasers in line). When I want to engrave a water bottle, it starts cleanly, but after a while the line shifts (with and without filling). I have tried many options, but nothing works as requested.

Here is a test on PVC (it's the same result on a bottle).

• Wanted :

• Reality :
  • Laser 3

• Laser 2

• Laser 1

Note that all 3 lasers receives the same TTL signal and if we engrave the same design with same configuration, the result is different on each occurence.

Here is the engraver configuration :

• 3 lasers syncronised and piloted by an TTL signal
• 1 nema 23 for the rotation with belt drive
• 1 nema 23 for the lasers moves
• CNC controller is a makerbase mks dlc v2.0 with 2 external nema 23 driver (MKS TMC2160)

Picture : https://imgur.com/a/XwitpV4 Config : https://imgur.com/a/5fvQwcd

My question is why at a given moment there is a lag...

Thanks for your help.

Nathan

[cgmllr100]

Is there a chance your pulley on the stepper motor is loose? the problem looks mechanical in nature and a loose pulley, shaft lock collar, or coupler can cause shifts like what you have in your pictures.

[Nalofox]

Hi,

I don't see lose step, i will add rubber on rotation bar to prevent very small shift.