Drag Knife

grabcad

I was inspired by Brian Oltrogge's (Grunblau) video online about his drag knife effort, so I thought I'd see if I could come up with something similar, and easy to fab on a CNC router.The sections I've drawn are thinner than his; it's designed for Aluminum. It needs one part cut out of 6mm thick stock and the rest out of 3mm. It should work for end mills up to 6mm diameter. All of the 3mm thick bits are identical, save for the one that is tapped, so in theory they could be done without changing the tool. All bolts are M5.The expectation is that the mounting rod and the blade holder will be pressed into the bearings, but not heavily so. I don't think the drag knife is meant to be axially loaded, so the fit, while it should be snug, isn't designed to support any weight.UPDATE 2 September 2016I initially published the model before I added any drag length. The model now has approx 1mm of drag. Also, I've discovered that not all blades are created equal. You'll want to check the model isn't too loose or (more likely) too tight for what you intend to use.