I finally pulled the trigger and built a pneumatic cylinder/belleville washer type power draw bar for my Shopmaster Mill Turn. I had previously built and posted a draw bar using a butterfly impact wrench for which the long term results were lacking. The torque seemed to be unpredictable and temperamental based on air pressure. The impact wrench sometimes would stick and bypass air. I may not have had large enough supply. Also, over time, the socket and bolt head started to gall and stick. I was afraid I would get galling on the draw bar threads.

I'm very happy with the new system and its performance. Here is a video review of it:

https://www.youtube.com/watch?v=P188_Xuwogw