Involute internal splining?

Anybody here have access to tooling to make involute splines inside a gear? It's metric, 16 splines on a 26.6 OD shaft.

I have a file and three more vacation days if that helps

Man, that's a tall order, you'd need a serious broaching setup with the correct die or a CNC EDM machine, right?

Wally wrote: I have a file and three more vacation days if that helps

Your "file" better be a CAD file and then you'll still need access to some machines.

Or someone with a shaper. For those not into old metal working machinery, a shaper holds the work in a vise like on a mill, while a cutter not unlike a lathe bit is pulled across it. The machine lifts the tool on the return strokes, and the vise steps over. They're perfect for cutting internal splines, much like the equally obsolete horizontal mill is suited to external splines.

Manual mill + broach + indexing rotary table

There's probably a shop local to you that could do the job.

Standard machine shop operation. If there are any machine shops left that do anything but production CNC work.

You've got me curious what this is for, as most internal spline applications I can think of off the top of my head do not actually use an involute tooth profile.

motomoron wrote: Or someone with a shaper. For those not into old metal working machinery, a shaper holds the work in a vise like on a mill, while a cutter not unlike a lathe bit is pulled across it. The machine lifts the tool on the return strokes, and the vise steps over. They're perfect for cutting internal splines, much like the equally obsolete horizontal mill is suited to external splines.

Except you would have to disable the "step over" function and use an indexing head to hold the part. PITA, but I have done it years ago. Biggest problem now would be finding a machine shop that still has a shaper.

Driven5 wrote: You've got me curious what this is for, as most internal spline applications I can think of off the top of my head do not actually use an involute tooth profile.

It's for a motorcycle transmission shaft. It fits on the shaft like this:

I'm trying to adapt something that shouldn't be there in the finest GRM fashion.

Sounds like the perfect location for the liberal use of JB Weld.

I"m thinking JB Weld won't hold ~150 HP at ~ 7K RPM.

I've done it with a slotter, that's a shaper in a vertical position.

Does this gear have to slide on the shaft? If not, you could reconfigure the current shaft and the gear, then weld the two together.

How about a NC EDM machine (like JohnyHachi6 suggested)

They are good for creating arbitrary shapes in difficult locations, in tough metals.

Might not even require any pre or post machining heat treatment.

How close does the fit have to be?

Quick Googling found this:

http://www.vwbroaching.com/wire_edm.php?kc=k0Svl&tsid=msnppc&utm_source=msn&utm_medium=ppc

ThomasNet is a great resource for finding specialized services:

http://www.thomasnet.com/north-carolina/edm-25331000-1.html

Changing to South Caroline didn't yield nearly as much though:

http://www.thomasnet.com/south-carolina/edm-25331000-1.html

Curmudgeon wrote: I"m thinking JB Weld won't hold ~150 HP at ~ 7K RPM.

Does it have to come back apart? Or is this like a yoke fitting.

Like a yoke fitting. It's going to be the input side of the diff drive in the Berzerkeley. As in, sprocket on one end outside the gearbox driven by the engine, then double sprockets inside on that same shaft with chains running to double sprockets on the diff.

I'd really like to use a HyVo chain but the cost of custom sprockets (necessary to fit in the available space) gets stupid in a hurry.

Try talking with Dave Hawk at Hawk machine in NY. He make driveshaft adapters so he has some way of doing it and he's smart guy with CNC etc. http://www.hawkmachine.com/

The suggestion of wire EDM is probably the most economical. A single drilled hole through the center and then cut the shape. No special tooling required

As long as you can provide a sprocket with the right outer teeth and have the CAD files to be converted into machine code.

The surface finish won't be the smoothest, but not bad and fairly smooth after electro polishing.

Curmudgeon wrote: I"m thinking JB Weld won't hold ~150 HP at ~ 7K RPM.

then leave off the "JB" part and just weld it.. if it has to come back apart, well, then i don't know what to tell you..

I'd like to weld it, but the shaft steps are such that the gear has to be removeable so the bearing on one side can be installed. Also, my last attempt at welding stuff like this was, shall we say, less than successful.

44, I'm going to catch up with that guy at Hawk Machine. Thanks! If he doesn't work out, I'll see if I can find someone with an EDM machine who won't completely murder me on a one off deal like this. I understand an individual who was associated with the RoSpit has that ability.

How about a key and locking bolt, ala pulley?

I just ordered my BE driveshaft adapter from Hawk Machine, he seemed friendly and answered my silly questions politely and quickly.