Scan Angle Questions

Community Laser Talk
1

I am engraving 18" maple plywood…
When I change my scan angle to 90 degrees I get a much better burn then at 0 degrees. So I rotated the plywood 90 degrees and kept the scan angle at 0 since it is quite a bit faster. The results are NOT as good as engraving with a 90 degree scan angle.

Can anyone tell me why I am getting consistently better fill engravings using a 90 degree scan angle? Common sense would think that if you rotate the plywood grain 90 degrees at a 0 scan angle you would get the same results… I do not.

Any insight would be terrific!!!

2

This could be the reason right here, though you haven’t said anything about how the engraving is “better”, just that it’s better, which could mean anything.

When you run slower, the wood gets more heat, and will char more (darken) instead of just vaporizing, so if “better” means darker, then that’s likely it.

If the edges are fuzzy, that would mean you haven’t set up scanning offsets (also called reverse interval compensation), and when running faster left to right you’d be more likely to see this offset.

So, what do you mean by “better” ?

3

Here is a discussion about using ‘Scan Angle’, when, why, and what results could be expected that might help with understanding.

4

Thanks for the replies and help!

  • Rick, I did find that post yesterday and found it helpful.

  • Oz, By “better” I mean darker. I run the same specs for both 90 and 0 scan angles…
    100 watt / Ruida
    350 mm/sec
    14.5% Power
    225 LPI

When I say that the 90 degree scan angle takes longer it is because I am ASSUMING that the gantry travels farther past the design on the Y axis compared to the X axis. The settings are the same except for the scan angle of 90 or 0.

In LB the time estimate is the same at 53 minutes each. However with the 90 degree scan angle the actual time it takes is 77minutes to complete the job. Zero scan angle jobs are extremely accurate as far as the time estimate - 53 minutes.

So I guess maybe it comes down to that even with the same setting for both angles, I do not really know the speed of the 90 scan angle because of the controller or machine. ???

Thanks again guys for your help! Love the software. It’s by far the best value I have in my arsenal of Adobe, Corel, Vetrics etc…

5

350 mm/sec might be faster than your machine is allowed to go in Y when engraving, but you’d need to check the Y axis speeds to verify that. Aside from that, yes, the Y axis acceleration will be lower, and will give more overshoot, so the estimates will likely be off by more than when using the X axis. (We don’t currently account for the overshoot on DSPs)

6

Thank You Oz and Rick.

I will figured out my 90 degree scan angle speed and slow my 0 Scan Angle down to the same speed to get the same results. Much Appreciated.