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EDM for Production?

MHSR130

Plastic
Joined
Sep 11, 2018
Hi Everyone.
I’ve got a part that’s fairly complex and the more I look at EDM, the better fit this process seems to be for production. Burr free cuts and flatness requirements for some areas of the blank are a big factor in this decision.

303 Stainless Steel

General tolerance of .001"

The part blank is roughly 1.1”L X .350”H X 1.9”D.

The WEDM Profile cut is 3 inches in total length and is cut to the full depth of 1.9”.

There’s no taper associated with the cut and within that total wire cut path of 3”, there are 2 surfaces totaling .20” that need a 16 micro-inch Ra finish, all other areas can be the EDM standard finish.

The wire cut follows the outside profile only so as far as I know, there should be no threading required for each piece.

In addition to the blank, there’s a slot cut that measures .050” wide that requires a sinker EDM cut to a depth of .170”.

The minimum volume is 5 thousand parts.

EDIT: I understand what a print/drawing is worth but won't be posting one here. I'm hoping I included enough info for you guys to determine if I should continue designing for production edm.

My questions are:

1) Is this part blank a good candidate for nesting and stacking parts for lights out
WEDM production? If it can be stacked, can a .001” flatness requirement be
repeatedly produced?

2) Is the volume a good fit for the part size?

3) Would the setup cost for wire, sinker and traditional machining(a few holes) be
too costly for the final part?

4) From what I’ve read, using a larger diameter wire would be better suited for
production. Is there a significant difference in cost and cutting speed between
.010” and .006” wire?

5) I don’t need a detailed number quoted but can anyone give me a ballpark figure on
part cost for those volumes either in this thread or a PM? Even a range for the
EDM profile blanks without the additional cuts would be helpful in deciding to
continue pursuing EDM as an option.

Sorry for the long post and thanks for taking a look.
 
Hi Everyone.
I’ve got a part that’s fairly complex and the more I look at EDM, the better fit this process seems to be for production. Burr free cuts and flatness requirements for some areas of the blank are a big factor in this decision.

303 Stainless Steel

General tolerance of .001"

The part blank is roughly 1.1”L X .350”H X 1.9”D.

The WEDM Profile cut is 3 inches in total length and is cut to the full depth of 1.9”.

There’s no taper associated with the cut and within that total wire cut path of 3”, there are 2 surfaces totaling .20” that need a 16 micro-inch Ra finish, all other areas can be the EDM standard finish.

The wire cut follows the outside profile only so as far as I know, there should be no threading required for each piece.

In addition to the blank, there’s a slot cut that measures .050” wide that requires a sinker EDM cut to a depth of .170”.

The minimum volume is 5 thousand parts.

My questions are:

1) Is this part blank a good candidate for nesting and stacking parts for lights out
WEDM production? If it can be stacked, can a .001” flatness requirement be
repeatedly produced?

2) Is the volume a good fit for the part size?

3) Would the setup cost for wire, sinker and traditional machining(a few holes) be
too costly for the final part?

4) From what I’ve read, using a larger diameter wire would be better suited for
production. Is there a significant difference in cost and cutting speed between
.010” and .006” wire?

5) I don’t need a detailed number quoted but can anyone give me a ballpark figure on
part cost for those volumes either in this thread or a PM? Even a range for the
EDM profile blanks without the additional cuts would be helpful in deciding to
continue pursuing EDM as an option.

Sorry for the long post and thanks for taking a look.

I've been out of the general wedm game for a little while, I'm sure Marcus (implex?) will show up with much better thoughts. :)


4) From what I’ve read, using a larger diameter wire would be better suited for
production. Is there a significant difference in cost and cutting speed between
.010” and .006” wire?
Not sure about cost, but yes on speed. I think you could even gain a little on .012" wire, but not sure how common that is.

The wire cut follows the outside profile only so as far as I know, there should be no threading required for each piece.

More than likely, threading will be required if you nest the parts.
 
I'm interested in any and all advise from machinists so thanks for the info. One more question to add.. What happens to the slugs when they are cut through? In other words, do they hit the wire and short or does the wire break and that's why it needs re-threading? That's one question I wasn't able to find anything on. Thanks.
 
Depends on the size of the slug. If small they fall into the tank, you stop the machine and remove them, then continue with skim cuts if you need them. If large, they may need to be supported by a magnet or strap so they don't damage the bottom flush cup. If the slug is the work piece you want, you leave a tab (or 2) and skim to size , then cut off the tab with the wire and second operation wire off the tab or surface grind the tab.
Most wire breaks happen when the wrong amount of power is put into the wire, during a change in thickness of the work piece, or entering or leaving the work piece.
Happy to look at your application if you post picture or print.
 
5000 how often?
A week, a month, a year, a decade????
Rarely is EDM alone used for a production process. It does have it's place.
........"Not enough information to process this question."
Bob

The initial volumes are estimated to be five to ten thousand for this year. After that, there will be steady work as things are tweaked and new parts are introduced. Continued yearly volumes of 5-10k are unlikely and my best guess would be around 1k per year after the initial order.
 








 
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