In this video I will show what I do with my broken end mills, how I reuse them. I have quite a few of these and decided to make some use of them, giving them a second life as drag engraving needles, scratching the surface. I simply designed and made one out of a 3D printed bearing holder, a linear bearing and an ER11 collet chuck holder with a 100mm long 8mm diameter shaft, a spiral spring, two washers and a locking ring with set screw. Easy, simple and very fast design and make. I will use it for engraving very fine lines, drawings and text into plastic and metal. In fact, my initial tests show excellent results even for steel. Of course, acrylic is no match for this tool, it is engraving very nicely, without any trouble even with a very light down press.
I will in some of the next video show actual use of this tool also, in this one you can see a quick example at the end, but only in acrylic.
Enjoy, and please don't forget to subscribe to my videos.