Non-proofgrade cut setting?

Using birch ply that is 0.13 thick. Non-proofgrade.
Manual settings asks for manual cut and passes.
Does manual cut depth mean same as focus height?
I am trying to cut through the ply I engraved…hopefully!
If cut is set at .13 will it cut through the material if focus height is also .13?
If not, do I increase cut depth, power, the number of passes of cutting, or slow it down?

Each sharer of knowledge earns a gold star :star:️ ! Thanks, pb2u2 in Paducah

2 Likes

You’ll have to experiment to get final settings for the wood, but I’d start with medium Birch ply, change to manual and slow it down a bit. Then check it without moving the wood to make sure it cut all the way through. If not, cut it again.

1 Like

For 3mm (1/8") baltic birch ply, I usually pick medium maple ply from the proofgrade settings, and then up the speed to 180 zooms.

But your mileage may vary.

4 Likes

As you’re cutting, you have material to spare, so create a simple line, and perform test cuts outside the desired area with the suggested settings. Selecting a similar PG material, then switching to manual, keeps the numbers and you can adjust from there after each test.

Not sure where you are seeing “manual cut depth” - you define material thickness for custom materials, and the laser settings ask for focus height as you say. They should (typically) be the same.

1 Like

As @eflguy mentiond, should be no mention of manual cut depth. What you should have is “Focus Height” under each job operation. This entry box is the height above the crumbtray that the laserbeam should focus at, so it generally coincides with the material height. In fact, this value is set by default to the material thickness that is entered into the unknown/use uncertified materials box when using non-Proofgrade materials.

You’ll have to come up with your own values for speed and power to get through the material. As others have mentioned, using the Proofgrade settings can be a good starting point. Your best bet though is to stick in a piece of scrap material and test it before you try to run the cut around your engrave.

3 Likes

Baltic birch can be wildly inconsistent between suppliers, and you should note that some suppliers use formaldehyde-based glues that are unpleasant to breathe in (3M makes a reasonably affordable formaldehyde vapor mask).

For Rockler BB ply, I use 125/full power, and keep a close eye on it (some glue pockets flare up). I’ve also used 140/full power and two passes, but that tends to really ignite the glue pockets.

I also have about a 30% failure rate on the cheaper BB plywoods, as they can have pockets of a filler material that’s practically impervious to CO2 wavelengths.

Conversely, I recently got some high-grade cabinet-maker plywood that cuts perfectly at 170/full power, or 140/80.

3 Likes