Variable number of passes?

Community Laser Talk
1

Long time lurker - first post…

Cutting 3mm ply with S30 Pro Max (about 2 months in - and loving it).

Currently using 550mm/min and 55% with two passes. Gives a nice clean cut with minimal scorch (air assist on).

Is there a setting I am missing that allows the speed / power to vary by the pass that the laser is on? I know the alternative is to tweak the speed/power so that 2 passes is not overkill - but was wondering if a second pass at higher speed would help decrease cut times?

Cheers
Glen

2

Hello Glen

Welcome!

A couple options.
The simplest might be to use sub-layers with different speeds.

Lets assume you wanted 2 passes at 55mm/min 55% power, then a 3rd clean up pass at 750 mm/min 75% power.
They will run in sequence within the same layer

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3

Perfect - I’ll give that a go on my next cut.

Thanks @ gilaraujo for the clear answer and screen shot.

G

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4

Using two layers of different speeds would not be my preferred method, I think. If you want to have maximum speed, then speed up your layers until it doesn’t cut through anymore. Then go back a little. So if 550 nearly cuts through, and you just need some areas to be cut again, then try two passes at 1000. If this doesn’t cut through, go back to 2x900, for example.

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5

400 / 50 just doesn’t quite in 1 pass (75%)
400 / 50 in 2 does 99%
450 / 55 needs 2 passes 99%
500 / 55 is clean after 2 passes.

Playing with power/speed to try and get the sweet spot between overall time of cutting (minimise) and lowest power.

Haven’t tried it, but suspect 80% at 500 would do it in 1 pass (but also looking to minimise scorch)

Enjoying the tinkering to be 100% honest.

Will try both on next cuts.

G

6

Keep in mind that plywood can vary substantially from peace to peace. Internal moisture and distribution of glue can cause one piece of plywood to not cut as well as another. Unfortunately, there is no way to tell from the outside.

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7

Totally run into that so far.

  • 3mm ply at 3.2mm (dealt with that in CAD)
  • Some boards warped slightly (dealt with that with wet sponge and hot iron)
  • Glue and hidden knots have caught me out a couple of times (Exacto knife and sand paper sorted that).

The other thing that caught me out (should have figured it through before) is the considerable difference in strength in ply (especially very thin) between “with” and “across” the grain. Doh!!

Gx

8

Yes, and be aware that most laser spots are not square but rectangular and have a better cutting performance in one direction.

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