Inconsistency when engraving. Is it the tube or ???

[Uros Sovilj]

Inconsistency when engraving. Is it the tube or ???

I am having this problem i can't figure out what can it be. When engraving acrylic i get those lighter lines. They appear random some time on beginning some time at middle etc.

I check alignment of mirrors and lens and all are ok. It's funny that i use same settings same place on table same focus distance and sometime i get those lines but jet next piece after 1 minute looks perfect.

I have also tried all possible combination of speed, power and resolution but didn't help.

Any idea why is this happening? I was thinking on some mechanical problem but doesn't make sence.
I am more thinking on power drops but can't figure why.

UrosProblem 1.jpg

[Dave Sheldrake]

Heat?

Check the right hand end of the tube for a bubble in the mirror chamber. Another cause can be re-deposited acrylic from the air assist getting blown back onto the job but more likely to be heat causing variation in output power.

cheers

Dave

[Rodne Gold]

Apart from what Dave says , the lasers are extremely sensitive to grounding issues as well as incoming power supply quality..we had issues with our mainstream machines with banding and using power conditioning helped.. also had issues with our chinese machines due to bad building grounding and just drove a copper rod into the earth and tied all the machine grounds to that and it stopped...you may have problem doing that in your area due to code violations or something tho..speak to an electrician..