RE: [CAD_CAM_EDM_DRO] B/S vs. acme was Re: What makes a machine CNC ready?

Hi Jon,

As I recall, your carriage is about 12" long. Do you remember how much the
Kerk assemblies cost? It must be WAY up there if it is 10X!

I've been perusing several lead screw and ball screw providers, and they all
want you to contact them for a quote. I'm still waiting for a quote! And
the fixings to request for the ends of the lead screw are a little
intimidating as well. ;>)

Application is a little PCB mill, 12" X, 12" Y, 3.5 Z. I finally got around
to using some of the surplus motion control stuff I'd collected, i.e.,
precision round rod with recirculating ball bushings, and ACME lead screws
w/ bronze nut bushings. It's almost built!

I did notice one drawback to using surplus components. The ball bearing
races that were used (8mm x 22mm x 7mm) don't appear to be standard! 8 x 20
x 7 seems to be widely available.

With a little effort, I may be able to slip in ball screws if needed at some
time.

Alan KM6VV

><snip>
> I think these Kerk screw/nut assemblies work quite well for low-load and
> moderate speed
> applications. And, the Kerk set cost almost 10 x more than the cheap
> ballscrew, but performs
> much better.
>
> Jon