Note: “Don’t waste” means to not use more than needed or to excess. It does not mean “leave untouched”. Refer to a dictionary on the word “waste”.
I’ve found that I can get much more consistent and less damaging cuts by setting the waste board as zero and then cutting down to it from the height of the piece in the machine. In this case the worst thing that can happen is I get a few air cuts in the beginning. For the alternative, setting the workpiece surface as zero, I can end up cutting up my waste board faster than I’d like or not cutting all the way through the piece.
This essentially moves any errors in my height measurement to be absorbed by either the safe move height buffer (and the first cut) or the air above my workpiece. I prefer this to errors showing up on my waste board or in a piece not being cut all the way through. Additionally, with the waste board zero method, any height errors show up during the very first cut. For the workpiece zero, any height errors show up on the last cuts.
For example, let’s say I have a piece that I think is 15 mm thick, so I enter that for my Z dimension in Easel. I might be wrong either way though, so let’s examine what happens if the material is actually 16 mm or 14 mm for the workpiece zero case and the waste board zero case. Note that in either case the machine can get to zero without error.
A - Workpiece surface is zero, workpiece thickness is actually -1 mm.
B - Workpiece surface is zero, workpiece thickness is actually +1 mm.
C - Waste board surface is zero, workpiece thickness is actually -1 mm.
D - Waste board surface is zero, workpiece thickness is actually +1 mm.
A - The workpiece is thinner than I thought, I cut through it by one mm, damaging my waste board.
B - The workpiece is thicker than I thought, the machine doesn’t cut all the way through the piece.
C - The workpiece is thinner than I thought, I cut one mm shallower than planned.
D - The workpiece is thicker than I thought, my safe move distance is one mm closer and my first cut is one mm deeper.
Note that the second method has the additional benefit of always cutting exactly through the piece.
All this would require is adding the material thickness to all the Z values traditionally calculated. Everything else works the same.
Perhaps a check box in the advanced options could perform this simple operation on all the Z values. I imagine this would be especially desirable for people who paid for the fancy Inventables waste board and don’t want to destroy it rapidly. Wrong place for this, apparently.