Here we go again...not using John's design so we have full rein on what we are going to do.
I have salvaged some slides from unused dot matrix printers and other equipment destined for the garbage. A little cutting, a little grinding and I should be able to get them to work.
The slides have high quality Thompson linear bearings. I have managed to get four of them out of the plastic carriers. I will reuse the bearings, and the stainless steel slides. The bearing assemblies need to have a tight sleeve to properly align the internal ball bearings.
The sleeve has to have 5/8" I.D. so a trip to Canadian Tire gave me two solutions. The first was a 5/8" I.D. steel pipe, the other was standard copper pipe fittings! Yes, a 1/2" coupler has a 5/8" I.D. and will work great! I will cut them to length, then use pipe clamps to fasten the trolley to the bearings.
The base and end pieces will be cut out of MDF, and the "standard" floating nut design with 1/4-20 lead screw.
Well, the construction went very well. I managed to build the Z axis in a night. It works really well and I am very happy with the result and the cost. I figure it cost me about $10 to build the Z axis (slides, bearings, lead screw, limit switches, MDF, paint - not including the stepper).
The Z Axis worked so well, I thought it did not work the first time I jogged it...it is so quiet, I did not hear it move!
Check the photo's for more details (uploaded later).
That concludes the construction info.