I’m downgrading Tarkin from Red to Yellow this evening.
After extensive testing this week by @dannym , @NickE, and some from me, there’s a few things to note.
Danny made a handful of improvements and tuneups in the hardware as well as in the controller to add stability and accuracy in the cuts. Nick’s cuts from last week vs yesterday were night and day different while using the same plywood and settings. I saw similar results with mine. While small patterns and tests were able to show smaller issues, the more consistent issues that have been popping up showed when we ran longer cuts spanning the bed.
Additionally, we were able to nail down a problem with some of the 1/4" plywood sheets.
TLDR; There is absolutely a difference in laser-able quality when it comes to plywood: Use interior rated plywood, not exterior. If you’re not sure, ask the lumber sales-folks.
There was one order that included some Baltic Birch 1/4" from a 4’x’8’ sheet. Normally I’d pick up the standard “Birch” 4’x8’ sheets which have not had any significant issues. The BB from 4’x8’ sheets however is the stuff that charred a lot and was hard to cut through. After a trip to Fine Lumber today with Danny, we learned the BB 4’x8’ sheets are intended for exterior use. This means it had a significantly different amount or composition of glue that ultimately inhibited a good laser cut. We tried a sheet of the Baltic Birch rated for interior use which comes in 5’x’5’ sheets. Despite being the same thickness, I saw a significant improvement in etching and cutting. I was able to move at speeds between 35 and 40 rather than the 15-20 for exterior rated BB.
Going forward we’ll continue to stock the standard Birch plywood 1/4" and Baltic Birch 1/8". When I make runs or order for delivery, I’ll be sure to ask that we’re getting interior rated plywood, just in case the manufacturer ever decides to change up their formula some day.
Why the Yellow Tag?
There are still some inconsistencies that can be seen detailed in this post:
While not a show stopper, these are signs to lookout for. It is not obvious what is causing this so please do report any issues seen as well as any signs of good runs. We are committed to a good quality laser for you all that can be used for your lasering needs.