Thanks rustyolddo,
This is sounding more reasonable cost wise. It sounds like I could do this with ACME or ball screws just as easily so I might start with ACME first to keep cost low, then upgrade later down the road if I feel it is necessary.
What do you think about this idea for pre-loading using the idea of bearings over the threads...
Fix one end of an ACME thread rod with a bearing sandwitched with appropriate nuts/washers and trap the bearing in it's machined mount on one end of the axis. On the other end of the axis machine a seat for the bearing so that the rod can pass through the mount, then on the "outside" you slide the bearing on and into the seat, follow that with a nut and torque the nut appropriately... this would create pre-tension by pulling on the ACME thread rod but would it be a satisfactory method?
I've got plenty of tools and woodworking machinery, I'm an avid woodworker and most of those tools will work aluminum "ok". I have plenty of carbide
I'll have to draw up some plans and post them to be sure I'm getting things right.