What temperature would you want the bronze blank to be ? I really don't have much tool and die experience which is kinda the territory we're getting into here. Casting is always another option. I've poured 70#s of bronze before at my shop, if you where to do the same, make a male up with the 0.010 clearance and then cast around that. I wonder if you would be able to get it out afterwards ? I'm wondering if some sort of release would work ? Maybe smoking the shaft like babbit ?

casting would be iffy, the nut will contract onto the shaft as it cools. Very hard to get out. Maybe if you made a dry-sand core... but you'd still have to make an internal spiral in your core box and sand-casting is less precise.

Cast it in two halves, just like I outlined for forging.

So I'm seriously considering trying this. I've dug out the change gears for the old mill at work and I think I can come up with something for a thread. Might not be too standard with the gears I found, but I'm not exactly worried about interchangeability. I've got a fair bit of Aluminium bronze kicking around, what do you think of using it as the nut material ? Also any ideas on making sure the bronze doesn't stick to the steel mold ? I was thinking smoke it like babitting but not sure this would work for such high heat. And now the real question. What the heck am I going to to with the thing when its built. I already have a fly press.....

Change gears? Mill? What exactly are you going to mill? And how?

I'm planning on cutting the threads using a helical milling set up on a mill. The change gears go from a dividing head to lead screw on the machine. Rough em out square with an end mill and then just go back and throw the thread angle on after.
Way easier than trying to cut a four start 2" lead thread on a lathe.

I have a K&T universal mill with the thread milling attachment and the dividing head with the outboard power takeoff to sycronize the feed and the cutter so that you can mill threads like this I have made one and it was a big pain. I think you should forget this and move on with your life. This is a tough job for even a very skilled machinest let alone a hobbiest.

Sounds more like you're talking about milling the screw, I thought we were talking about the nut.

Grant, you're the one who suggested forging the two-piece nut onto the screw. You even told him to make a second, oversized male part ( ) as a mandrel.

You're losing it, man. That was only four months ago. :P

What was?:blink: