Homebrew PCBs

On Mon, 16 May 2005 19:43:49 -0400, Bill Blackburn  
<billblackburn@...> wrote:

> Hi Guys
> I am going to start building a small CNC milling machine (X = 7", Y =
> 7", Z = 6") for machining PCB's and I am wondering what I should be
> using for the Feed Screws?  I am not sure if a small machine like this
> warrants installing Ball Screws?  What about using a good stainless
> threaded rod and a split nut to adjust the backlash?  I have a Sherline
> Mill with Stepper mounted directly onto the screws and I find the travel
> speeds to be very slow.  Sherline use 18 threads per inch on their Feed
> Screws.
> What are you guys using for your feed screws?  When using directly
> mounted Stepper Motors, what would be a good thread pitch for reasonable
> travel speeds?
> Thanks for the help.
> Bill


I will use M8 stainless on my machine. I think the pitch is too small but  
it will only travel slower, i can live with that.
Don't have the money for fancy screws.

ST