I did a search and I could not really find a answer so I post the question here. When I flatten the sacrificial board I know my cnc will not reach all the way if I measure and cut the board to fit the full length and width of the cnc the X,Y will not reach and I will have basically have a raised end all the way around. The flattening bit will be 1 1/4" across. So do I need to just measure or mark on the board where the outside cutting edge will be and just cut my board that size? I have 1/2 sheet of 3/4" birch plywood and using it at my sacrificial board
Couple options: 1) knock down the remaining edge after surfacing, with a handplane or sander 2) learn to love the raised edge as a precision alignment edge to butt stock up against before clamping - its great for that! 3) install a smaller sacrifial 1/4" MDF spoilboard of the exact dimensions on top to provide clearance Main spoilboard = full machine bed size - do not shrink it - it plays a role in holding the machine rigid too...
Cool, didn't think about a built in edge. And with premium birch plywood being expensive I will go with MDF
