[jime]

I’ve got a part that lends itself to wire EDM (see attached). I’m getting quoted about $1K per part. With a projected need of 10 units per month, plus 10 each of other simpler parts, I’m thinking of installing an older edm unit to do the parts. Could I get some advise on the following:

1. Is WEDM the best for this part?
2. I’ve been told to look out for a Mits 90 series, or Elox O, Q, or R series. Any one familiar with these?
3. Know where one might be available? Price?
4. Any other suggestions?

Thanks!

Jim

[joepiejan]

hi Jim,
I'm working with a hitachi hi-cut. do you mean they charge you $1000 a part ?
Maybe i can help you with some, if you have a more detailed side view of the part. or 3d part, and i prefer metric if possible.

Jan

[Mi_WireGuy]

Hey Jim - I took a look at the DXF it definitely seems like wire would be the best choice for this.

Are they building the complete detail for a grand, including material, machining, grinding etc? You have around 23 inches of travel and a couple setups here.

Also is your tolerance +/- .0002" I noted the 4 place decimals, if so that would require some extra skimming to hold tight I am sure.

Depending on how this detail were laid out, and the tolerances, I would probably quote about $500 WIRE ONLY and that could be reduced depending on HOW the initial part is laid out and setup.

Regarding purchasing a wire and DIY, a Mits 90 or Mits FX would be a decent choice, ELOX, not so much. I would be thinking SODICK...

Good Luck,
TC

[roysol]

Presuming a tight tolerance on 4 place decimals, and a fine surface finish greatly add to the expense of EDM. The other important point to clarify is what inside radius you could accept in the areas where you have sharp corners drawn.

The typical most productive wire size for that part would leave a ..0055 to .0065 radius. If you want a smaller radius, there are shops working with under .001" diameter wire, but the cost goes up exponentially. Also keep in mind that regardless of processing order, the second (and possibly third) operations will not have good flush conditions, as you no longer have parallell top and bottom surfaces.

I think it would be a good wire EDM job, but some more detail is in order.

Cheers!

Roy Solomon

[jime]

That should only be three decimal places! .002! (just a small error!). The radii are not that critical. Shoot, we're cutting them now on a mill with a and a cutter! Jim

[cincinnatimachine]

I have just calculated that we would take about 25 hours to wire cut that part. The thick piece (2.6") can be done be done with good flushing, but then the second cut, will have no way of getting water jets close to the job. For production work like that, we charge NZ$ 60 per hour, so we would be looking at about NZ$1500, US$1125 for those parts. That is as a single cut, no skimming. I am presuming you are talking some form of steel here, not aluminium.

If you are looking at buying a machine, you could try Tom Truty [email protected] They deal in second hand Agie machines, which he fully reconditions and puts in a better flushing system and improved spark generation, making a reasonably high cut speed machine.

Your quote of US$1000, is therefore not bad, so this is the sort of figure you are looking at, or you need to redesign, to make production cheaper.

Regards, Colin

[cincinnatimachine]

Whoops it is early morning here. Just looked at the drawing again and I have priced cutting it all by wire cutting right round. With correct preparation, my previous figure could be cut down considerably, maybe half that price.

Colin

[jime]

Jan: My local salesman is trying to hook me up with a Hitatchi. It's a flushing type, 1991 model. Is that similar to yours? Hows the Hitatch?

TC: Wirecut only...no material...no grinding.

Roy: Tols only +.002, radii not so critical

Colin: Thanks for the info..yes, steel.

Thanks for the advise, guys. What should a decent second hand machine run?

Jim

[Mi_WireGuy]

I definitely think this is around a 9 or 10 hour wire job, being conservative due to the poor flushing conditions. this would definitely vary based on the layout of the block as Colin stated.

Regarding the H-Cut, keep in mind that there is no service or support for Hitachi in the US as far as I know. And electronic parts are VERY hard to come by. In my opinion I would stay away from that machine (far away). It would probably take you twice or MORE time to cut this part in that machine.

For a decent used or re-furb wire you will probably spend $20 - 30 K, I would definitely get something submerged cutting and auto wire threading. I would recommend in order > 1) Sodick 2) Fanuc 3) Mitsubishi.

I know alot of people like the Agie and Charmilles machines also, but I have very little experience with them so I cannot recommend them.

If you would like to discuss the best way to configure the block for this let me know.

Regards,
TC

[sodickappsguy]

I would agree that this is a EDM job for sure. One thing to keep in mind that most people starting out is that you should buy a machine that fits the job size. I see alot of people buy machines that are way to big for the job it is bought for and later trade in for a machine with a smaller foot print and cut area. I agree that submerged should be used and get a macnine that is still being made today. Just cause you can get a deal doesnt mean it is a deal when it is sitting there needing parts and there is no one to buy the parts from.

Smaller Dia wire means slower speeds but higher finish and tighter tolerance. (In the US most people use .01-.012 dia for speed and in japan they use .008-.004 and go as low as .0005 dia). Most machines you can get away with 2 cuts. If the tolerance is .002 that is wide open for EDM but the surface finish requires the second pass. I know a dealer that buys older EDM (all brands) and refurb them and give a warranty and training. If you would like some info on them or have any questions send me a PM and i will be happy to talk about it.

[jime]

Thanks for all the great info. I've gotten some quotes for less than half of the original. We're milling everything now and we're doing some time studies to see how much we'll save by EDMing and whether to farm out or purchase a machine.
Jim