Homebrew PCBs

Ed Okerson wrote:
>> Maybe but its a matter of pure luck that any given person comes across
>> one of these small drill machines your talking about. And spending
>> $1000's on a brand new drill machine is just not an option. Building a
>> CNC machine from scratch is a mammoth task compared, to building a
>> manual drill press.
> 
> 
> That is simply not true.  I built a CNC mill/drill based on the Brute
> design at www.crankorgan.com and it only took about a week to make it. 
> Granted it is not a professional unit, but it is accurate down to
> 0.00025", plenty good enough for hobby PCB drilling!  It cost virtually
> nothing to build, mostly scrap aluminum channel and scrap plastic blocks.
> 
> Ed Okerson
> 

They look interesting, but what is used as the linear slides ? How are 
they attached to the U channel ?
Is the lead screw standard zinc steel threaded bar or is it  the true 
thing ?
It looks like X, Y and Z axis are identically built, with only the 
length of the Z axis being smaller.
What CNC software are you using ? Did that take a week to write too ?
And most important, what is the minimum tooling required to build one of 
these ?