That video is impressive. The surface speed is really the information there and the hand work is like any master craftsman. Utterly amazing to the layman and way harder than it looks!

I really enjoyed watching him do the hollow grind. I have fooled around with that on my burr king grinders but getting the part same cut multiple times with the same coverage has evaded me. I was amazed at the material removal rate without a burr on the back-side during the profiling. Thanks for sharing that.

I don't really understanding what you are describing for your process.

When I freehand miter I use a belt on platen or disc and grind the profile that (on a bike) would be seen from the side of the bike. On the roll cages I use a chop saw and make two cuts and finish it on a 20" disc then tamper a bit with a big 1/2 round file.

'pics would be great!

I will try to get a film of what I am describing also!

This was something fun from a couple of days ago. I bent and mitered these tubes on this piece of medical equipment for these two brilliant young engineers. We went through the steps one by one to get the information I needed out of this massive 3D drawing to make these tubular parts that were pretty basic compared to a bicycle chain stay.

I did the two end cuts on the long bent tube like a typical machine shop would then the lower miter on the long up-tube and both cuts on the smaller tube were done by hand. It took two days to bend, ovalize one end and miter the main tubes and no more than 5 min to do the last three miters on the little home made belt sander in the background.


29 1037 by frankthewelder, on Flickr

Two more fun things in the photo is the bottle brush and touch up grinder way back in the photo. The bottle brush is a motorized reciprocating wire brush with about 2" of stroke. The machine on top is a regular bench grinder mounted up at eye level so I can really see to do fine work.