Introduction: Use a Metal Lathe to Alter the Diameter of a Lead Screw

I'm building a Thickness Sander and I'm using Acme Lead Screws to raise and lower a table on the sander.

The plan calls for taking a 3/4" lead screw and turning off an 1/8" of steel from the lead screw so that the bronze bushing (see red circle) fits over the lead screw. 


Step 1: Securely Hold the Part in the Lathe

This lathe has a collet that can be changed to work with any diameter material that you need to hold.  This system is far superior to a 3 jaw chuck for holding steel.

Once you have securely held the rod, you need to use a center drill ( picture 2) to drill a 60 degree hole to allow for the tail-stock live center quill  to then support the work as you turn it down.




Step 2: Turn the Part Down to Size With a Carbide Cutter

In this video, I was not supporting the end of the rod and it was bouncing all over the place and I was getting a really poor cut.

http://youtu.be/gPzyyDrC7Ug

Once I got smart about the was I was doing this process -- and used the center drill, then supported the work with the live center, things started to go well.

The trick in doing this is to support the work, put oil on it to cool it as it cuts, and go SLOW. 

It took me a while to get the hang of cutting the threads off, but it worked out.

I had to alter 4 acme lead screws on each end of the rod.  I was able to use the DRO to make sure that I took off the right amount of the diameter, as well as the length of the material that needed to be removed.

I made these parts at TechShop.

Comments

author
mrbreezeet1 made it! (author)2014-12-02

is that a leadscrew off a lath,or just acme threaded stock from a metal supply?

Do you know if the leadscrew in my 10" Logan can be drilled?

I want remove the lead screw, and extend the leadscrew through my spindle, and center drill it, so I can drill and tap it. Do you know how hard the logan lead screw is?

author
CWKr made it! (author)CWKr2014-12-02

That is a 1" diameter Acme Thread that is being turned down on the lathe so that there is a shoulder.

I don't know what a logan lead screw is. Lead screws are usually made of metal that can be drilled and tapped.

author
mrbreezeet1 made it! (author)mrbreezeet12014-12-03

Thank You, It is the Lead screw from a 10" Logan lathe.

I want to set up a gear motor to drive the lead screw nice and slow.

(The lathe has no quick change gear box)

(Of course, if I want to thread, I will just use my change gears)

I took the bearing off, and nicked it (the leadscrew) with a file, and it filed pretty easy, so yes, I think your right, it should drill OK. I will pull the lead screw and indicate it in, in the 4 jaw, and center drill and drill and tap it to hold my gear.

that Logan only has about a 3/4" through hole in the spindle, but I was lucky, the leadscrew is about 5/8"

How did your sander turn out, is it done and running?

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