I was doing some cutting earlier in a really difficult material - 3mm MDF. I was cutting some small components which needed to slot into each other, and after the first attempt none of them fitted. Measuring, I found that I was getting dimensions consistently about 0.7mm out. That was averaged over a dozen or so different dimensions, internal and external. I regenerated the gcode using a cutter of nominal dimension 2.3mm instead of its theoretical 3mm, and all the pieces cut and fit perfectly. Question is, is it my crap machine bending with the strain of a 1.7mm DOC in MDF, or is it likely to really be cutter size? It's a single-flute carbide cutter from CNCRouterParts, but I can't check its diameter directly as it is single-flute. I don't have much experience with these kinds of cutters - do you need to do trial cuts to find out their effective cutting diameter before use? I'm happy to blame the machine, but curious about cutter accuracy as well.