Algemeen's Electronics and Bicycle Tinker Blog

Made the SIFAM collet knob tool today! And it turned out quite nice, see the pictures below. I don’t own a Proxxon or Dremel. Instead I used a normal 550Watt Metabo power drill at 2800 RPM. The maximum setting.  Such tiny diamond coated grinder bits are usually run at about 20000 RPM, so this made progress a bit slow. For a one-off it’s okay.  Proxxon Micromot 28 240 diamond coated grind bit (1.8mm) It’s a bit awkward to steer such slightly heavy machine for those small movements. To ease the grinding process, I’ve put the extra front handle in a horizontal position. Also used a bit of drill/cutting paste to improve cutting performance. Tried to apply as little force as possible since such miniature bits aren’t made to be used under high loads, such as with normal HSS/Carbide milling or drill bits. Because it’s more a cylindrical steel shaft instead of a disk type tool, it probably is a bit sturdier. The Metabo power drill with grind bit. WARNING: Never try the other Drem

Last time mentioned ordering cheap 8mm slot screw bits, 1.2mm thick. This to make my own SIFAM collet tool. Received the bits with a bit of delay, just before I left last weekend. It is a small pack of 3 bits for €2.75 so one bit is about only 90 cents. When unpacking, I was slightly alarmed by the claims ‘Extra Hard’ and ‘Made in Czech Republic’. So this actually might be very good quality, instead of the cheap and soft steel I had hoped for at this price... Bosch 2 607 001 468 Extra Hard S8 bits Tried a small needle file file on it, and can confirm it is really good steel. Instead of using a lot of patience and elbow grease ordered a Proxxon Micromot 28 240  diamond coated grind bit (1.8mm) for about €3.49 Bit clampled in a small vice with red marker     Will try it in a drill at a high RPM setting and gradually mill a small indent, as marked inside the red region in this picture. If it fails, still can have two other tries.