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vacagary
10-09-2002, 01:02 PM
I'm looking for information on milling external splines. All of my books are silent on the subject. Are special cutters required? Where do you get them. When I examine the spline, its sides are square but the space between the splines is a trapazoid. Any leads will be very much appreciated. Thanks Gary

John Stevenson
10-09-2002, 05:46 PM
Gary,
This is covered very briefly in Machinery handbook. In their infinite wisdom this isn't under splines but under Milling Cutters - Spline.
The cutter needs grinding to an angle that is equal to the sides of the spline. This is 360 divided by the number of splines. The width of the cutter at the tip is equal to the width of the bottom of the spline. Machinery Handbook gives formulae for this but it's as easy to measure it. Any decent tool and cutter grinding place can do this from an old side and face cutter. This just then requires a simple indexing operation to cut the splines.
See http://homepage.ntlworld.com/jodiebell/spline%20cutting.jpg

An alternative way to use standard cutters is to do this in two cuts. The first cut is made using two identical thin slitting saws with a spacer between equal to the width of the parallel spline. All the splines are cut at the same setting. The work is then indexed round 1/2 a spline and the excess material is removed from between the two previous saw cuts with a wider cutter. The bottom of the spline can be left flat as the outside diameter will locate.

John S.

vacagary
10-10-2002, 12:56 AM
John
Thanks for the great response. I really appreciate you taking the time.
Gary

chip's
10-10-2002, 10:05 PM
Vacagary,
I know you said milling splines but a shaper sure works great for this type of work.
Rick

Uncle Dunc
10-10-2002, 10:16 PM
You can also cut splines with a hob. Not the same tooth form as a gear hob, obviously, but the procedure would be similar. I don't know if you could do free hobbing, where the hob drives the work. You might have to have a gear driven hobber.