Homebrew PCBs

> What the heck is the thing on
that mpeg video???

   Look up "propeller clock" on the net.  Bob Blick gets the credit for 
putting it on a motor which is brilliant, but a friend and I were doing 
the same thing on RC Heli blades for night flying visual a year or two 
before his site.  Actually there are toys with similar ideas back to at 
least the late 70's early 80's.

 >    It is a very interesting machine... Do you have more pictures or
drawnings of it ???

   (CNC that is)  Not yet, although it's pretty simple.  I may 
eventually sell some on Ebay, but even then may still decide to put up 
some plans.

Ted Huntington wrote:
> That looks impressive.   I guess those are bipolar motors that you
> attached to gear reducer heads and control with a serial/parallel
> port?    That is interesting that you were able to use brackets that a
> person can buy at most hardware stores I guess.  Can you use a drill
> file from software like Eagle to do all the drilling from the diagram
> automatically?  I guess because you have to change the drill bits by
> hand, you have to edit the drill file then.  Are you using a chip like
> the HIP4081A or a PIC like PIC16F77 to control the motors?
> 
> This person has a useful tutorial on a home-built PCB drill/mill:
> http://cryolite.ath.cx/i/pcb-router
> 

   Yep bipolar.  My controller is my own design and will run any stepper 
5 phase or less.  No gear though, just straight shaft to 1/4"-20 
threaded rod.  That is 200 steps X 20 for 4000 steps/inch.  Do have 150 
or so geared Vextas if I needed them, but never used many so far because 
they're 3600 steps/rev to start.  Need coarser pitch ballscrews for those.

   My controller is intelligent, and the basic program on the PC just 
outputs coordinates to it and waits till it signals done moving.  Easy 
to do the drill files from Eagle, and I typically just have it go 
through the file twice.  First does the smaller drills with one bit, 
then lets me bit change and does all larger drills with another.  Two 
drills that have one doing the smaller range of holes and one the larger 
is pretty effective, little need for 10 real drill sizes on a homemade 
board.  Actually I largely surface mount now, so not so many holes 
anyway.  It's 16F877 based on the controller.

   Thanks for the refresh on the link, I've seen it before but it's been 
a while.  There were reasons I went with the gantry though, to build a 
larger CNC it gets cumbersome to have the hanging fixed Z.  Have to get 
my second generation controller board done now though, it's similar but 
much advanced over the first one.

Alan