Homebrew PCBs

Richard Mcfarlane wrote:

>Dear Master Mr Curtis  Richards,
> Gratefully received your two replies about my EDM
>query.For a long time I was searching for a real EDM
>master who could guide me to build a CNC -EDM.
>Now,I am fortunate to be acquainted with you!
>Before contacting you I wished to buy Camtronics-EDM
>plans.But now I have decided to buy that nice EDM
>book-by Mr.Ben Fleming which you have referred to me.I
>have Mr.Langlois EDM book.I also have EDM plans-By Mr.
>Peter Rawlinson and many Patents about EDMs.
>If you need to see any/all of these then please do not
>hesitate to let me know.I will be happy to co-operate
>with you.
>I like to learn more and more about your EDM
>experience. I am only an amateur EDM diy hobbyist.
>As I have stated previously that I intend to make a
>CNC -EDM with a Ball-Screw designed quill, I will look
>forward to see what more help I can get from you.
>I am also anxious to see your EDM results which you
>will publish on Homebrew PCBs groups.
>
>Best Regards.
>Richard.
>  
>
Hi Richard,

Please just call me Curt, I'm retired and have left  Mister, Master, 
Doctor and Professor on the scrap pile   :-)

I've been experimenting with the Fleming RC or relaxation design.  It 
cuts PC boards as fast as the Garden of EDM design, but has the 
advantage of costing MUCH less since you don't need the IGBTs.  About 
the only change I would make is to use a 2N3055 as a variable "power 
resistor" instead of the wire wound type.  Using kerosene as a 
dielectric scares the heck out of me so I used 36 volt AC transformer 
for my power supply ( and used higher voltage parts throughout    :-)    
) which when combined with the variable "power resistor" allowed the 
Fleming servo design to with de-ionized water as a dielectric.

I'm thinking of setting up a fiberglass laundry tub to work as a tank 
for a wire EDM so I can put my Garden of EDM power supply to better 
use.  With a Lexan cover on hinges it should be as least as safe as my 
parts washer  and would some interesting metalwork.  I'm thinking that 
the laundry tub is designed for conventional PVC plumbing so sump / 
holding tank should be easy to rig up.  Add  a spin-on automotive oil 
filter in place of the drain trap and you are in business!  The 
dielectric pump could use the filter as a pickup and you can use the 
tub's stopper  when you need to change the filter.   Of course 
sparkproof housings for the steppers and EDM head servo are a concern...

Have you investigated various wire transports?  Does the wire need to 
travel like a bandsaw blade?  Or can you use a fixed wire with a flood 
of dielectric?

It would be an interesting project since you would end up with poor 
man's "laser" cutter.  I'm thinking of really good looking cabinets for 
electronic projects or maybe an inexpensive way to build a Zoltar style 
machine for PCB drilling...


-- 
Curtis W Richards

--

"The natural progress of things is for liberty 
 to yield and government to gain ground."
 --Thomas Jefferson