Polishing fine details

Hopefully someone can point me in the right direction. We are looking into a 'system' (vibratory, ultrasonic?) to polish edm scale of small details. Something like 1/4" x 3/8" x 2", with small cutouts ranging down to .05" x .1" deep. Ideally we could get to a 16 or so finish, but not sure if that is possible.

I tried my google-fu but it was weak and didn't turn anything up that looked promising. Maybe using wrong search terms...?

thanks

Have you tried electropolishing? What is material and hardness?

Blast media: plastic, walnut shell, CO2?

Aluminum material. Neever used any vibratory tumblers or anything so I don't know anything about different medias. I imagine walnut would be too coarse as the features are pretty small.

I'll search electro polishing, thanks.

Give these guys a call and ask what they've got for your needs: sPINner Deburring Machine for Small Parts

Would vapor honing be sufficient? It leaves a polished and closed pores (unlike dry blasting), but doesn't remove material like regular media blasting. I use 170-325 beads in the machine and parts are quite polished without significant material removal. The machines are kind of expensive for what they are, so I converted a regular dry blaster to vapor using a pond scum/mud pump with a bypass valve to keep the aggregate.

EDM scale is a very hard thin coating, I can't picture any sort of vibration system working. Based on how our mold polisher always bitches about it, you will need something much more aggressive. There are tempering processes that our local heat treating company does that softens the "white" layer but it's doubtful that would be much help. You will need some form of abrasive if you actually want to remove the layer. You can blast all day on it and maybe hide the porous surface a little bit and discolor it, but you will have the hard coating.

Hi Mike1974:
A lot depends on what you hope to achieve as it always does.
My background is in mold polishing, and there are criteria for that kind of polishing that don't necessarily apply to other kinds of polishing but here are the Cole's Notes for mold cavity work.
Paramount is the preservation of the geometry especially at the parting line, and the lay of the micro scratches that are left when the polishing is complete.

So if you're mold polishing you'll invest in getting those things right because it is supremely important.
For what I do, there are basically two ways forward.
One is hand polishing with abrasive stones.
The other is power polishing with a gadget of some kind and abrasive stones or diamond paste charged laps, hones or bobs.

It sounds like you're after a gadget.
Two kinds to look for for mold polishing:
One is called a Diprofil and is a mechanical reciprocator with a fairly long slow stroke, a bit like a jigsaw for woodworking.
The other is an air powered reciprocator with a very short fast stroke; NSK makes a very nice but very expensive one.
You clamp in the abrasive stones, turn it on, apply it to the surface, and instantly fuck up the parting edges unless you know what you're doing.

If that matters, you have to learn how.
Gesswein and other abrasive stone suppliers offer courses that are well worth taking if you do this often enough to want to get good at it.

With respect to which abrasive stones for EDM surfaces, there are a gazillion out there.
Every manufacturer offers EDM stones which typically are harder stones than those used to polish a milled or ground surface.
This is to get through the HAZ that 5 Axis Fidia Guy refers to without wearing the stone so much that it loses its shape too fast.
Once the layer is removed, conventional stones take over to develop the proper finish.
In addition, sometimes fiber reinforced ceramic stones are needed to polish small details and sometimes diamond paste impregnated wood or copper laps are needed in order to sneak into the tiniest details.

That's about it...you're just rubbing the stone on the surface but it takes patience and discipline and skill to do it efficiently and well.
I farm out most of my polishing now; there are specialist firms who do nothing else and can turn around a mold cavity faster cheaper and better than I can ever hope to.

Cheers

Marcus
Implant Mechanix • Design & Innovation > HOME
Vancouver Wire EDM -- Wire EDM Machining

Interesting read on recast....

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