Richard Mcfarlane wrote:
>Hi Curtis,
>>From Homebrew PCBs-Groups, I came to know about your
>interest regarding EDM.
>I am also an EDM diy hobbyist like you. I built
>several EDMs from the following plans :-
>
>1. Build This Space-Age EDM -( Popular Science,Mar-68)
>2. A Light-Bulb EDM Project--(Meadre Hanks)
>3. A Spark-Erosion Machine--(C.Roy Amsbury)
>4. An Workshop EDM--(Peter Rawlinson)
>5. Build This Shop EDM--(Robert Langlois)
> I observed these machines have poor mechanical
>constructions and moreover the EDM power supply are
>RC-Types.These are very slow and crude metal removal
>process and presently obseleted.
>
>
I agree! My prototype machine uses Thomsom linear slides mounted on
ground plate. I use 1/2 inch - 10 acme rod for lead screws. I used a
lead lap to remove any "drunkenness" and a double bronze nut to take up
backlash. I prefer the acme thread since speed of traverse is not an
issue and the "stick-tion" is an asset while EDM head makes a cutting
pass across the PCB.
> My friend Mr. Graham Stabler advised me to use PWM
>EDM Pulse Generator--to control Gap-Voltage and also
>cutting rate-Fine/Rough cuts.The "Garden Of EDM" uses
>this principle.I modified PWM power Supplies from
>various EDM Patents.
>
I've had good luck with the Garden of EDM supply, but I'm now working on
a Mosfet version controlled by a PIC that will be cheaper to build and
more flexible
>Camtronics EDM plans are also
>based on PWM technique.The mechanical construction is
>also very rigid.
>Regarding the Up-Down servo electrode quill
>movement I prefer to use a ball-screw instead of a
>lead screw to eliminate back-lash error.
>
>
My prototype uses a stainless 1/4-20 rod with a double nut. Although I
lapped the rod and used Teflon nuts I think you are right -- a ballscrew
would it's higher cost
>I will look forward to know more about your comments
>or advce to help me for building a CNC - Sinker/Wire
>EDM.
>If you need any help from me also I will be glad to
>co-operate with you.
>
>
I've started a thread on Yahoo's Homebrew_PCBs and will publish my
results there. They are a very helpful and innovative group. I'll be
glad of any comments you might care to add and will happily answer any
questions. My postings will be limited for a week or two as I am
looking for the "right" digital camera to document my prototype and I am
tied up on the circuit redesign.
>Regards.
>Richard.
>∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗
>
>
I'll post a copy of this e-mail and very likely Stefan or Dan will have
something useful to add.
--
Curtis W Richards
--
"The natural progress of things is for liberty
to yield and government to gain ground."
--Thomas Jefferson