Since .375 did not work, I thought I was focusing for a thicker piece of wood.?? So I should try it at .188? Should I change the speed and power too? Very new at this.
As a rule of thumb, you don’t want to have a focus that is above (higher, larger #, thicker) than the material for cuts. Defocusing is okay for engraves - it can be very good for smoothing acryclic engraves.
So for cutting 3/8" Baltic Birch I’d go with a focal point midway into the material (.188"). Then experiment. I run test calibration designs for all new materials. I start with full power and then set the calibration steps (colors in the design) based on similar material. If I don’t get clean cuts, I’ll start again and add in another pass.
There are a bunch of threads here on calibration tools & their use. You should be able to find one that you like and can use.
The other thing to check is to see if the plywood has voids or solids in between the veneers layers. If you shine a very bright flashlight from the back of the plywood you’ll see those. Also, real Baltic Birch will be more consistent than plain Birch plywood. You’ll get the former from specialty wood suppliers (or Amazon) whereas the big box stores will have regular Birch ply.
I understand setting the focal point. Not sure what you mean by calibration… colors in the design. What I am trying to do, there is no engraving, it is all cutting through. Go full power and start with what speed? There is nothing similar to the 3/8" thick in the Glowforge materials.
There are designs posted here that have for instance 10 boxes. Each of those has a separate color. In the GFUI you would set the power & focal point constant (say Full power & .188") for each color. Then you’d set each color to a different speed - say 10, 20, 30, 40, 50, 100, 200, 300, 400, 500). Run the job. It will try to cut out the boxes with different speeds.
When you’re done you’ll have a piece of material with a bunch of boxes that didn’t cut out, some that you’ll see almost cut out and some that completely cut out with various levels of char. (Hopefully)
You use the cleanest cut as your setting (or you can run it again with speeds in between a cut that was good and the next one that wasn’t.
In your case, I’d do my settings between 5 & 100 as you already know it won’t cut through at 100.
If you don’t get any that cut through or they’re only charred & not brown or toast colored, go back and run the same job except change the # of passes to 2 for each one. You’ll then see how well it cuts with different speeds & passes.
I have project designs posted that allow you to do this for cuts and others that allow you to see the effect of speed & power on engraves. Search for “calibration tool” or “calibration template”. Several people have posted their own designs to do the same thing.
There’s nothing special about the number of boxes in the calibration tool designs - my cutting one has a dozen or so I think - it’s just a matter of how many colors can you keep separate and so how many operations you want to set the settings for in the GFUI.
Once you do this for a given material it makes it pretty easy to pick the speed you’ll need to get what you want.
would you share your settings for 1/8" Bocote? I can’t find anything on the forums except people saying they could or couldnt but no setting being posted? please help.
My notes say:
Cuts nicely at 140/full/1x, 130/full/1x. Leaves a lot of residue.
This is on a pro. If you are not on a pro, your “full” will be different from mine.
As always, that’s a guideline, and very small variations in thicknesses can matter a great deal.
It was difficult enough that I decided that bocote was not worth my trouble, and switched to figured walnut and Wenge as my go to “dark brown” woods. Walnut cuts almost as easily as any other hardwood (it’s about like maple), wenge is a bit tougher, but it’s much easier than the ironwoods, rosewoods, and bocotes of the world.
You can see the walnut in effect here:
I have a basic machine and my settings for 1/4 bocote have been working very well. For 1/8 I simply cut the passes in half. The settings I have for 1/4 are speed 190, power full, 6 pass and 0.22 focus height. So for 1/8 I do like 2 or 3 passes. I’d start with 2 passes.
I make pet name tags with absolutely beautiful bocote. Sooooo pretty.
I hope these settings work well for you too!
A thing I have done when cutting half-inch plywood was to do a deep engrave that was a quarter inch deep, Then there was only a quarter inch to cut through.
Zebrawood will turn totally to Ash If a coal can get started. With most wood, it will stop when the cut moves on.
If the cut almost makes it a jewelers saw will finish the job.