[BeerFizz]

Hi,

I acquired a Thompson ball screw off of EBay which seems to be in good condition and I was thinking of using this for my Z axis on my Mini-Mill conversion.

The ball screw appears to have a diameter of .7235 inches and a lead of .2. I don't know if it's ground or rolled, but there is a small grove on the 'apex' of the threads if that helps (you can see that on the pics).

The thread portion of the ball nut appears to have a diameter of 1.2465

There is no apparent backlash (testing by hand) and the nut takes a little force to turn but all in all it's quite smooth.

What I would like to do is purchase an additional length of ball screw (about 30 inches), have it machined and then transfer the screw over.

So, my questions are:

What are the specs on the screw and where can I get a short length?

What are the specs of the thread on the ball nut, so I can a get a flange and where?

Finally, what are the issues of transferring the ball nut from one screw to another?

Thanks
Phil

[ViperTX]

Sounds like it's a 3/4 inch (0.725 diameter) the 18 and 20 mm metric are much smaller or larger. Thompson Industries, or there is a guy on ebay that sells them with oversized balls in the nuts...don't know if he will sell you just the ballscrew. I think Nook is interchangeable with Thompson and you can get those at McMasterCarr.com.

[BeerFizz]

Thanks Viper... Thats a help.

Phil