Halcohead
Stainless
- Joined
- Apr 10, 2005
- Location
- Bay Area, Ca
I have a part on my unicycle (well two) where there's a very tight slip fit on a 3/4" 48 spline interface. I'd like to make one of these (manual machines, sadly no CNC), and I'm wondering what kind of tolerances you would choose on these things. Yes, I understand that the size and shape of the splines matters, but I don't have the tools to measure this. I would figure they are at most 0.075" tall. The material is 4130 cro-mo for both parts, although the axle is occasionally done in titanium.
Furthermore, what would you use to make this? I was thinking a dividing head on a VERY beefy horizontal mill (I have a friend who will let me use his gigantic KT). Get a cutter with the shape of the splines, and do a single, full depth pass. Use the removal of the cutter as a finish pass, using the flex of the mill to allow it a bit more meat to smooth out. Once I have the axle made, grind a HSS cutter to fit with these splines, and put it in a small boring bar on a shaper.
The issue I have is that there's only one shot on the shaping of the internal splines. I can't imagine being able to take down and remount the part in order to test the interface.
Sorry if this is an elementary question for some of y'all. It seems rather difficult for me, mostly because I'm not even sure how exactly to tolerance the splines.
I would make a broach fort the internal splines, but from what I understand, splines of that size require gigantic broaches. Also, I don't have an arbor press that could drive a broach of the size I figure I would need. Is it possible to make a single tooth broach that runs in an indexing collar? It would index off one initial spline that is cut on the shaper. That way if the splines are slightly too tight, I can just shim the broach and cut a bit more off?
Furthermore, what would you use to make this? I was thinking a dividing head on a VERY beefy horizontal mill (I have a friend who will let me use his gigantic KT). Get a cutter with the shape of the splines, and do a single, full depth pass. Use the removal of the cutter as a finish pass, using the flex of the mill to allow it a bit more meat to smooth out. Once I have the axle made, grind a HSS cutter to fit with these splines, and put it in a small boring bar on a shaper.
The issue I have is that there's only one shot on the shaping of the internal splines. I can't imagine being able to take down and remount the part in order to test the interface.
Sorry if this is an elementary question for some of y'all. It seems rather difficult for me, mostly because I'm not even sure how exactly to tolerance the splines.
I would make a broach fort the internal splines, but from what I understand, splines of that size require gigantic broaches. Also, I don't have an arbor press that could drive a broach of the size I figure I would need. Is it possible to make a single tooth broach that runs in an indexing collar? It would index off one initial spline that is cut on the shaper. That way if the splines are slightly too tight, I can just shim the broach and cut a bit more off?