galaxy
10-20-2006, 01:03 PM
I want to build an EDM power supply, therefore i need some specs to come to a good design.
So the following questions arises:
AC, DC, or PWM ?
Frequentie ?
Volts ?
AMPs ?
Anything else ?
It is intended for light-duty EDM. Let's say PCBs :)
I am able to design a processor controlled power supply.
I am willing to publish the schematic on this forum, after i have succeeded.
Thanks in advance for your replies.
Theo
Mat-C
10-21-2006, 01:50 PM
From my research (currently building my own WEDM, so not actually tested)
AC: pretty advanced, used to avoid surface electrolysis, esp. for titanium.
DC: Do you mean capacitor discharge? Easy/works/slow.
PWM: Standard "DC" methord, should be reasonably simple to make.
Volts: Commercial machines seem to use 27 to 250v. Bigger voltage = easier life (larger gap) but more dangerous. Seriously, be careful.
Amps: Try it and see... more amps = faster cutting, but speed isn't your first problem.
PCB's: you also need to control the z height fairly accurately I'd think. What do you plan to use for a probe?
Are you upgrading an existing machine or starting from scratch?
galaxy
10-22-2006, 04:10 AM
To start with your last question, i'm starting from scratch.
I intended to make a pcb milling machine. Lucky enough i stumbled over EDM before i actually made the Z-axis.
Power supply: Maybe the best solution is to make a PWM-contolled one in the whole voltage range you mentioned.
I have a 4 AMP variac at home. Maybe that is a good starting point.
I found on the web a dedicated forum about DIY EMD.
For me, it is the place to be...
http://tech.groups.yahoo.com/group/EDMHomeBuilders/
Thanks for your reply.
Theo
Mat-C
10-22-2006, 12:12 PM
4amp variac should do it. Be careful with those voltages! Use an RCD on the mains side and have an audible and visible warning of the wire being possibly live.