The slide rods are Thomson 1/2" rods in Thomson linear recirculating bearings. The slide is approximately 3" wide by 3" deep by 12" long (with the stepper motor installed.) It has 3" of travel. It has several holes in the back plate for mounting; 4 holes 17/64" and 4 holes tapped 1/4-20 in addition to a 1/4" reamed hole in the center for locating.
The lead screw is 1/2-10 acme with a direct coupling to a size 23 stepper motor. Thrust is taken up by a flanged bronze bushing and lock collars. Single full step reolution is .0005". I have one like this on my PCB machine,(see picture below) and have been using it for 5 years now with no part replacements. The holder you see on the slide holds my motorised spindles for PCB engraving.
Well, I'm on the third run of Instant Z Axis slides and let me tell you, this is hard work! I am far enough ahead on spindles and slides so that I am just assembling now. I found a good source of aluminum for slide bodies up in Phoenix at Capitol metals; a giant metal supermarket with shopping carts with 500 pound capacities. I counted the thomson bearings I have left and I have enough for 25 more assemblies.When the Hardened rods are gone, the price will go up $20.00 to pay for brandy new t-rod in each slide. When the bearings are gone, that's the end of it unless people would be happy with Oilite bushings.The price for now is still $105.00 without a stepper motor and $120.00 with a bipolar or unipolar stepper. Shipping has run around $16.00 so far. The bad news is that the surplus bearings for the spindles will be gone in 6 more assemblies.Then the price on those goes up to $45.00. I would like to thank those who trusted me to produce a precision product and were not afraid to have faith in their fellow man. Also I would like to thank my beta testers, in particular Brian Foley. And finally, to my mother, who left us January 24/03, thanks for always being amazed and delighted at my little gadgets.You were an island of compassion in a sea of indifference.