Broaching Question

I couldn't see the number and size of the splines in the part in your photo, but I'd say that broaching is the way to go, particularly if they are rather shallow cuts. Probably best to leave cutting the clamping slot until after you do the broaching.

Are you planning on making these for just one make and model of bike? Are the shifter shafts the same size on other bikes?

Just Googling up "broach" will get you plenty of manufacturers who will give you a quote for what you need, once you send them a drawing of your part and tell them what the material is. Be aware that you will probably suffer sticker shock when you get the price.

Frankly, I'm a bit dubious about your being able to come up with anything along the lines of what your photos show which will take the strain of a few unintended hard pulls, pushes or knocks without failing somehow. I think you putting just too much leverage on a small splined shaft, but YMMV.

Good luck,

Jeff

For a low-volume application, I'd look for a heavier lever on another make of bike that has the same splines and enough material to cut, drill and thread for the handle. Then buy new levers to modify. I bet that would be cheapest.

I don't have the number on hand, but they're definately not cut very deep.

I was planning on making just one size, fortunately it will fit serveral makes and model years of older Triumphs, and possibly other British bikes.

Yeah, I'm guessing the price may stop me dead in my tracks.

You're likely right, my plan is to use aluminum to limit the weight on the spline and make the end around the spline beefier than the one in the picture.

Thanks, I'll google for some manufacturers.

Thanks for the suggestion, I'll do some searching to see if I can find a compatible shifter as an alternative.

Tony

Perhaps another tack would be to have the pieces cut by the wire EDM method. A CNC wire EDM machine should be able to crank this part out, including the clamping slot in short order.

This suggestion came to mind because at the last Meeting of the New England Model Engineering Society our speaker was Bob Bouley ,an application engineer at Methodes Machine Tool Co. in Sudbury MA. They specialize in Wire EDM and have, as I recall him saying, about 80 machines on the shop floor.

A big advantage of this method is that there is no tooling cost for you. You would just have to provide a drawing and they could take it from there.

Errol Groff

Instructor, Machine Tool Department

H.H. Ellis Technical High School

New England Model Engineering Society

To be blunt, I really didn't see anything in your photographs that would lend itself to broaching. Perhaps you can explain.

Do you understand what broaching is, and some of the applications where it is typically employed?

Were I you, I'd stick close to someone with a milling machine.

Harry C.

I'm no machinist, so I'll admit that this is the first time I've ever heard of that, so you've given me something new to look into, thanks for the info.

Tony

Harry wrote......

Not entirely, I'm green when it comes to metal work. I was thinking that broaching would be the process of pushing a tool through the part of the shifter that would fit over the splines of the shifter spindle in order to cut the corresponding splines. I could very well be mistaken.

Thanks, I've been given some areas to research that may be an alternative to broaching that I'll follow up on.

Tony

Make part , heat red hot , slip over spline die , squeeze with a mold using hydraulic jacks for pressure , cool off part and clean it up ? Forging seems ideal for this . Luck Ken Cutt

He's looking to broach the splines in the hole that mounts to the shift lever. Broaching is appropriate there. Forging over a mandrel would work too.

Cheers Trevor Jones