8mm Tubing Cutter

Simple change to r2pDos's model to fit an 8mm tube instead of a PTFE tube. Works for any plastic or rubber tubing with an 8mm OD, I use it for Kegland's EVABarrier tubing.

I also only use one M3x10 screw to clamp down the blade, and an M3x12 for the hinge. The 10mm clamp can thread directly into the plastic, no need to use a nut. Simple box cutter blade slots in, as in the original model.