Does anyone know how to turn down the end of a 3 foot threaded rod? Currently I’m doing it by rotating it by hand on a bench sander. It’s 5/8 so it does not fit my drill.
This is definitely metal lathe territory.
@John_Bump would a piece that long fit in a lathe? I’d consider buying one if that were the case.
Here’s an ugly hack I’ve done before: find a couple of bearings that are larger than the threaded rod, use some glue to adhere them onto the rod (this is a temporary thing) then stick some rubber hose onto the rod and clamp that in the drill chuck, and clamp the bearings in a vise. That way you can at least spin the rod and put a file against the end, and you’re much more likely to get a concentric cylinder than trying to rotate it evenly by hand. Then when you’re done break the glue loose. I’m thinking epoxy and use heat, but I suspect even wood glue would work. It doesn’t have to stick well, just provide some support. You could even wrap electrical tape around the threaded rod and press the bearing on.
Also, it depends on the lathe. There are lots of lathes that would fit in just fine. You can either get one with a more than three foot bed, or one with a headstock that has a greater than 5/8" spindle so you can put the rod through the spindle. (Generally if you do this you want to put something on the other end that’ll prevent it whipping around. I use a piece of plywood with a hole drilled in it slightly larger than the stuff I’m working on, clamped to something convenient nearby.) That’s a LOT of money to pay for this job, note, but it’s exactly the right tool.
I have run into quite a few situations I would have liked a lathe but was able to hack through them one way or another. Thank you for the advice.
I put my lead screws into bearings as others suggested and drove the rod itself with a pulley and a belt. I removed most of the material with an angle grinder then finished up with a file and some stones http://i.imgur.com/j36Ocil.jpg You want to spin into the work so the work sucks into your grinding wheel. Otherwise you get a lot of bounce.
