Answers to Bicycle Lathe Questions
Don Weber’s Bicycle Lathe article in the August 2007 issue (#163) has sparked a lot of interest and questions. So below, Don has provided answers to some of the repeat questions. He’s also working on a plan drawing for constructing a bicycle lathe; we’ll let you know as soon as the plan is available, and how you can get it.
Concerning shaft dimension and fittings: I used a 1″ cold-rolled steel shaft procured from my local machine shop. Any 1″-diameter shaft will do; it fits a standard pillow block available from most hardware stores. The bicycle sprocket, purchased from my local bike shop, is a standard 13-tooth, single-gear sprocket. I had our local machinist turn a collet for me to thread into the fine threaded hole in the sprocket, leaving enough collar to drill and tap for a Ã?Â¼” 20 set screw. You can turn your own collet from hardwood (I’ve made one from Lignnum Vitae), but steel will last longer.
The attachments for the flywheel and faceplate, or grinding wheel attachment, were 1-1/2″ floor flanges with a 1″ reducer. The extra reducer allowed me to drill and tap for the 1/4″ 20 set screw. The floor flange does not have enough shoulder to accommodate a set screw. I had to drill out the threads in the reducer with a 1″ drill on the drill press. I did this by screwing the flange and reducer to a scrap of plywood, then clamping the plywood to the drill-press table. It made holding the reducer more secure and safe. It also helped to keep the bore true to the shaft.