keyways

As a gear manufacturer, many of our parts are keyed. For jobs with large keys & parallel sided splines, about 3/4 width, we have done by wire EDM. These gears are typically about 3" thick. Volume is, 10-15 parts/month. Outlay for EDM work often exceeds combined value of other operations. Am exploring adding this capability in house. Is this a feasible idea? If so, what entry level, used, machines and pricing should I consider?

Machine type/age would be dependent on your tolerance needed. Don't be so quick to settle for something old and cheap that will hold +/- .005" on a straight keyway. If you take a look at what newer machines are capable of in the gear cutting realm, you just may find they'll open up new avenues of business or make some of your other machines obsolete.

A 3/4 wide keyway (let's say 3/8 deep), in 3" tall material is 1 1/2" linear times 3" talll equals 4 1/2 square inches of burning. On my relatively slow Mits FX10K, that would take less than an hour to rough, even accounting for bad flush at the entry and exit. Add another hour to trim.

Less than an hour of set-up and programming, at 10-15 parts/month, maybe what you need isn't your own machine, but a new vendor.

I have posted more times than I can count about the perils of shops without EDM experience starting out with a used machine. The learning curve is steep, and EDM's are notoriously finicky. Without manufactures support, you could be in for a world of hurt. I would at least consider getting a reconditioned machine direct from an authourized distributor to give you a better chance.

(Edit), All that being said, I cut keyways and other internal features in our production parts, all the time. It's not a profit center for us, my boss wants to be able to take in work without regard to the secondary operations, and still be in control of our own destiny. If that's important to you, it may make sense, even if not economically speaking.

Cheers!

Roy Solomon.

PS, I would echo what Jay Cee said about EDM broadening your horizions. If you could justify the expenditure with enough work, you might not feel compelled to try and do it on the cheap.

I would invest in a low cost wire edm like an older brother most of the programming is done on screen and you can pick them up pretty cheap. You will have no problem with the machine they are easy to pick up on and easy to maintain. I don't remember what brother I used to run but it was a great machine I'll find out what the model was and give you another post tomorrow

What roysol said. We have seen many of our customers over the years buy their own WEDM or waterjet only to find out how "hard" it is or how expensive the machine maintenance is. Many of them no longer have their own machines and those that do still send the work they cannot or don't want to do to us.

That being said, you should take a look at the Brother HS-70A. I don't think you can get more for your money in a WEDM. It doesn't have all the bells and whistles of the high-end machines, and I wouldn't cut zero-clearance dies in it, but it's easy to use, fast, has a small footprint, built-in tech, and is affordable.

The other thing is wire EDM machines don't like to sit. I to have had customers buy their own machine to only use them once a week or so. Its not like a bandsaw or drill press you go turn on as needed. They are very high maintanance machines. Consumables and parts are expensive. There is also a learning curve. Most of my customers that bought their own machine have either sold them or pushed them to the back of their shops. One shop uses their machine for roughing parts for their mill and I still get the complicated and rush work from all of them.

As everyone says they are finicky machines. The bossman shut mine down for the weekend to save energy and I ended up spending the morning getting them back up and running which lost him more than what he saved by shutting them off completely. Go with a machine you can have free service phone calls to help you get through the problems. Also if there is a chance you will be getting another eventually, do the research so that you will buy the same machine the second time around. It is really handy to have a spare of everything to do troubleshooting with. We have troubleshot boards this way, it works like a charm because when you go ahead and order what you need you will be getting what you need and not just shooting blanks with a cost of a day of downtime each time.

Husker

Hi 10 Fingers
I used to cut keyways using a vertical gear shaper by disengaging the rotary motion of the cutter and use the machine like a shaper.
Good luck

Are they still soft? why not broach ?

I do allot of them with a Slotter.

Konrad