I bought a sweet ballscrew off ebay awhile back. It's 2" diameter with a 1/2" pitch. Two ball nuts in the center - they're flanged, and they're huge. The flanges where the two nuts meet are 5" in diameter. Total nut length is about 10". The ends of of the screws are machined and there are helical stops mounted by set screws. Total travel is around 42".

The screw is brand new and looks to be ground nicely. I paid $20 + $40 shipping. :cheers:

:boxing: :boxing: :boxing: