Powder coat generator used as EDM?

[ShavingMaker]

I bought a powder coating kit and it includes an electrostatic generator. Can this generator also be used as the power unit for an EDM?

[Thrud]

No.

[ShavingMaker]

Thrud, that is the shortest reply I have ever seen you give! Cat got your tongue?

[docsteve66]

Shaver: EDM needs low volatge (<100 volts so far as I can tell). Powder metal needs high voltage, almost no current (amps). The intent of the Hi voltage is to make the powder cling (like a silk slip on a winter day- thats a slip like a woman wears).
Steve

[darryl]

I wonder if a microwave transformer would be a good candidate for an EDM power supply- cut off the secondary, (with the sfmr plugged in, of course) haha , ok, anyway, cut off the secondary. Thread on about 100 turns, in groups of about 10 turns, for easier winding, making taps along the way to give various output voltages, and carry on according to plans. You might be able to eliminate much of the resistor network, as the transformer has a limiting feature already, by the magnetic shunts built in to it. I have not done any experiment with this, so take it as an idea only.
By the way, Thrud, elegant answer above. It's pretty hard to get confused by that one.



[This message has been edited by darryl (edited 03-30-2003).]

[Alistair Hosie]

I am impressed with the finish powder coating gives can anyone tell me how it works. I always thought you needed a large oven for this an am interested in this kit but would like to know more.Alistair

[ibewgypsie]

Allstair, I have built and sold powdercoat ovens. You hook the ground from the sprayer to the part, spray it till it looks like velvet then bake it at 400 degrees untill it all runs together like solder. Then cook it for 20 minutes to bake it. You can burn it like cookies if it cooks too long, I have. You can finish sand it to a slick finish, most times I ended up with a orange peel finish I had to polish.
I have a 5x5 foot oven sitting outside in the weather cause I have used all my shop up with mills lathes and english wheels. Bummer, I need a larger shop.

EDM.. SAve your money on the book on ebay, I got one and it is NOT EDM (ohojim seller). Charging a capacitor up and discharging it into a electrode with a gas shield is the right way.
There are good design books there.

[Thrud]

ShavingMaker:
Yes. You need low voltage high current (75V <30A).

Darryl

No. You almost need a welder transformer - not quite.

Alistair
You ever come over here and I will take you to a production powder coat line.

Their oven is 1,500,000 BTU and the stuff hangs on a line and passes through the oven. The paint room is about 140* and the painter wears a cooled suit. The paint is micronized plastic or epoxy coatings and can cause serious lung damage and should be handled like laser toner. The finish is super tough once cooled.

[dvideo]

On Ebay there are cheap Blue M ovens for sale all over the place (ie, CA and NE for sure - but also TX and Canada - all over).. I got one with a 24x24x20 box for about $150. 208V - single phase... I like them because they are precise - and I hope to do double duty with composites.

Sent my wife and son to pick it up. Won't do that again..... Bad idea..... no.. no.. no....

I can explain powder coating to them. Composites are a foggy explanation... but when I mention casting... well.. I stopped quick. One thing at a time...

Blue Ms are big, last forever, and heavy. Sometimes you can get a desktop that is just perfect size. It's the precision that helps make a qulaity job. Better than a home cooking oven. I have seen them go for pretty cheap, too...

Good Luck...

Jerry

[docsteve66]

Thrud: The HSM EDM uses lamps for current limiting. The home built edm that i have seen also use limiting resistros. My suggestion of <30 amps was based on the inability of a 200 watt lamp to pass more than 2 amps. My lastest practical experience with professional EDM used vacumm tubes so I am way out of date. Thanks for the correction.
Steve

[Thrud]

Steve

I am not sure what the newest machines are running now. They have changed quite a bit in the last two years and have super stable arcs and self feeding wires and what not.

The maximum current depends on the type of edm - Wire, Plunge, and the new ones I forgot.

[docsteve66]

Dave: Last one i played with had mercury vapor rectifiers, a BUNCH of 6L6 tubes, Knobs all over the place. Bunch of analog meters too. I THINK frequency, voltage and effective impedence were all adjustable. A real precise machine in the right hands. I suspet the newer machines have adjustments. I see Villagepress is publishing additions to their EDM, I intend to read every one. Still not planning to buid a home EDM. Iwill wait till i need one, then do it in a panic!!!! I got no brains
Steve

[Thrud]

Steve

I like the additions that Robert Langlois is doing to his EDM. The wire cutter is just what I need. I even have a spool of tungsten corona wire for it - don't ask where I got it.


Last mercury rectifiers I seen were attached to 140,000v line. The machine welded bridge plates 6"x1/4" on edge with round bar press welded into the bars. Not really spot welding, melted the bar into the plate - made them one. I can't remember how many amps it was, but I am sure it was well over 1.5Million Amps. The rectifiers were behind the machine and the whole back glowed blue. Made my skin crawl the closer I got to it.

They had a cool cold saw 36"x1/2" blade came up out of the bed to cut the 3' wide bridge plates to length. Had about a 25HP motor on a hydraulic drive. Nasty!

[Bullet-Bob]

Thrud -- What changes are you talking about? I am just starting my machine.Is it in one of the magazines? I am planning on building the modulator circuit from chapter 6. Has anyone worked out a good parts list for it.It would save lots of time.Thanks in advance.

[docsteve66]

bob- you asked thrud, but here is what I think: The modifications add to the old edm so you can chang it and stil use the oldstuff. He has not really done the mods yet. Hehas planned many mods. I think it will takein excess of ayear to get the whole things published. HSM is way to thing and deldom published. Two months is a long wait. But I intend to follow the series with interst.