Desktop EDM Sinker for Mold Work

Hello there,

I run a small company that makes small ABS plastic parts. I make small injection mold tools from Aluminum.

I've been wanting to get into making molds from tool steel and other parts that need small EDM features.

So I've been looking for a small EDM sinker machine. Main concerns are power usage (I'm in a garage with 3 phase 70 amps).Second concern is space. I'm running out of work bench space and that's why I need a small machine (also the parts I make are small).

Ideally I would like it to not use a whole lot of amps so I can still run my VMC and injection molding press all at once.

Molds/parts I make are well under the size of a 8.5x11" piece of paper.

Every now and then I will see a Charmilles brand machine on ebay for a couple thousand and they look like a desktop sinker.

Any advice or machines you would recommend. I would be buying used, I've never ran a EDM sinker before FYI.

Thanks!

You could also check into the benchtop Handsvedt machines. Usually come with a bench, and they run off of 115V. Usually find them cheap and complete. Anything I would consider buying would have to have the manuals! Also, go with a brand name machine as it's easier to find parts, and people that can help you with it. Good Luck! ------------------ John

Hi BrickTactical:
This is a subject that has gotten a lot of airtime on this forum over the years, so there will be lots to search and digest.
I encourage you to do so.

However, the short version follows:

First, sinker EDM is a process you have to think hard about before you try to do it in your garage.
The principal reason is the fire hazard; it's manageable with common sense but maybe not to your insurance guys.

Second, if you get an old manual machine, you have to get one that is not a beater, and it's not always easy to tell.
Truly old machines (1980's or older) overwhelmingly are hydraulic ram machines with two main drawbacks.
a) they're noisy as hell from the hydraulic pump.
b) the servo valve that controls the ram is just about unobtainable and it's definitely un-rebuildable, so if you buy a thrasher, you can't fix it.
So you MUST see it running and evaluate the servo valve before you lay down cash on such a machine; either that or pray a lot when you first fire it up after you bring it home.

Third, EDM is expensive and it can be incredibly dirty and stinky too...just the thing to keep your Lovely Wife happy.
If you buy a synthetic non-stinky dielectric oil like Ionoplus, it'll cost you well north of a thousand bucks just to fill your tank.
Super stinky Rustlick EDM 250 is not much cheaper and you might not be allowed back in the house after you douse yourself the first time, so be warned.

Fourth, sinker EDM, especially on an old manual machine is almost as much art as science, so it can be extraordinarily frustrating for a beginner especially if you have no help to sort it out, and even more so if you don't have the burn tables that came with the machine.

Fifth, to the best of my recollection, my Hansvedt sinker did require 3 phase input power and ran on a 30 amp breaker...that's what my current machine (also a Hansvedt but newer and CNC) needs too.

Last, and this is an unrelated note; you wrote "Molds/parts I make are well under the size of a 8.5x11" piece of paper. "
An 8.5" x 11" mold is not a tiny mold (typically 120 to 150 lb in steel), and an 8.5" x 11" part is a BIG part requiring lots of clamp tonnage to run safely.
At only 3000 PSI injection pressure you're talking about a minimum 150 ton machine just to keep the mold halves together, so I assume you must be talking about the size of the mold base, not the part.

Even so, If you buy a piddler like a Hansvedt SM 150 B you will struggle to use it on molds of that size unless you plan to insert all the cavities and never burn anything directly into the mold base.
Please believe me on this; I had one, and it was a great little machine but not for a mold plate that big.

Cheers

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

Hi - What kind of injection molding machine are you using? Thanks

Karl R. said:

Hi - What kind of injection molding machine are you using? Thanks

Click to expand...

Probably a toyo top injector...just speculation though.