looking for alpha prt z gantry

[Brian Heritage]

looking for alpha prt z gantry
mine is getting very worn
anyone making or selling a new one ?
Thanks
Brian

[Chuck Keysor]

Brian, I have a PRT alpha, but I have just gotten done re-doing parts of mine. Though I am a dabbler, I will offer an initial comment, with the hope that someone who knows more will offer their opinions.

1) I put in a new pinion.
2) As per a recommendation by Brady Watson, I added two additional V-bearings to provide added support to the Z assembly.
3) I re-aligned the Z axis.

I think that unless you have excessive lash in your motor, or you have worn out springs, that the above simple steps should be sufficient to fix you up........ Again, that is my non-expert opinion.... Hopefully I will have primed the answer pump for you........

Good luck, Chuck

[Brady Watson]

It depends on how much you want to spend...there are several options:

1) Shopbot sells a RetroZ with PRS style rails
2) Source your own steel and make another
3) File the edges true again and move the v-rollers up and over to compensate for the t-rail being roll forged smaller than 4.000".
4) Similar to #3, get a weldor to lay a bead on the edges to build it up (TIG preffered), then grind to spec. It ain't rocket science....SB used to grind the early PRT X rails with a belt sander.

It costs me too much to fab them and offer them for sale... which is why there aren't many options off the shelf.