- Joined
- May 30, 2018
- Messages
- 5
I'm looking to make an expanding lathe mandrel to turn the outside of a pad cup after the inside has been machined from nickel silver. Here's an example of a pad cup: https://www.windplus.net/supplies/pad3.gif
I've seen expanding lathe mandrels that use a socket head cap screw to tighten, but that works better for ring or tube shaped work. Since I wouldn't have access to the face end of the mandrel, I thought it might work to counterbore a hole in the shank (straight shank would be held in a collet) for a cap screw that pulls a cone shaped wedge. I'd have to remove the mandrel to remove the part, but I'm okay with that. I'd also cut a shoulder into the front outside of the mandrel to provide a square face to register the part up to.
Any suggestions or thoughts of what material to use for the mandrel? I'm thinking a cylindrical shaft of about 3/8". The parts would be 3/8" - 7/8" diameter and less than 1/4" overall thickness. I've thought of using 12L14 leaded steel or C360 brass. It's not something I would be using often or making a lot of parts with, but if I'd like it to hold up to at least a dozen uses. Brass would probably be easier on my slitting saw and won't rust, but I don't know if it would hold up.
-- Nate
I've seen expanding lathe mandrels that use a socket head cap screw to tighten, but that works better for ring or tube shaped work. Since I wouldn't have access to the face end of the mandrel, I thought it might work to counterbore a hole in the shank (straight shank would be held in a collet) for a cap screw that pulls a cone shaped wedge. I'd have to remove the mandrel to remove the part, but I'm okay with that. I'd also cut a shoulder into the front outside of the mandrel to provide a square face to register the part up to.
Any suggestions or thoughts of what material to use for the mandrel? I'm thinking a cylindrical shaft of about 3/8". The parts would be 3/8" - 7/8" diameter and less than 1/4" overall thickness. I've thought of using 12L14 leaded steel or C360 brass. It's not something I would be using often or making a lot of parts with, but if I'd like it to hold up to at least a dozen uses. Brass would probably be easier on my slitting saw and won't rust, but I don't know if it would hold up.
-- Nate