Homebrew PCBs

Quoting Markus Zingg <m.zingg@...>:

> Hi Stefan
> 
> I figure CNC drilling is definately on topic - at least if using
> lasers to drill and "mill" PCB's is on topic too :)) (sorry guys,
> could not resist - AND it was interesting)
> 
> With regard to the slides, the slides used in the link are NOT those
> I refered to. The ones I refered to DO NOT use ball bearings. Instead
> the balls are palced along the whole slide making it extremly stiff
> and precise. 

I don't know how the surplus market is in your area, but here we have
a semi-monthly auction for surplus goods from all over the state as
well as the state university system.

There are often mainframe racks with very well engineered rack slides
going for US$10 or less for the whole rack.  Using the standard rack
as the mechanincal base is easy, just lay it on its back.  Most of them
are steel.  If you get one of the smaller hard drive units it has
four very nice slides in it that are rated for several hundred pounds
and are very smooth so as not to crash the drive heads.

Other surplus equipment can have very good positioners also -- I once
got a Matrix camera for $10 that had meter-long threaded rods with
recirculating ball bearing mounts, and the complete motor and driver
schematic taped inside the door.

Sometimes scavenging gets you a lot more than you'd think. ;)
-Dan Barlow