Selecting involute spline cutter

pianoman8t8 · Jan 4, 2021

Hi all,
I think I have at least 1 involute spline I need to reproduce. It's a driveshaft for an old tractor that's no longer available, shaft snapped, 21tooth spline at one end, 19tooth spline at the other end. Maybe weld, re-turn section, re-harden? Doubt it would be overly straight after that...
Edit: This post was more intended to see if the cutter selection was similar to spur gears? Or, since it's a spline, different? I've cut a couple spur gears way back in trade school, but no gears since then, and no splines.

1st spline is approx 0.908" OD, 0.775" minor, 21 teeth.

2nd spline is approx 0.780" OD, 0.690" minor, 19 teeth. Considerably "flatter" teeth. Worn?

Phil in Montana · Jan 4, 2021

To make just one you will have to grind your own fly cutter and use a dividing head, not a big deal...Phil

pianoman8t8 · Jan 4, 2021

Phil in Montana said:
To make just one you will have to grind your own fly cutter and use a dividing head, not a big deal...Phil

Phil, I was sorta leaning that direction at one point as well. I just don't have much of a template to go by. Suppose I could take an impression with putty and match that as closely as possible?

Phil in Montana · Jan 4, 2021

Grind it close and push it in to the spline and see what light shines thru, or do the math and grind it straight sided, on old worn parts it works good...Phil

Turbowerks · Jan 4, 2021

From your numbers it looks to a 24/48 pitch involute spline, could be od , side fit or, probably won’t mater cause the hub is probably worn too.
Im with Phil, grind a cutter and get it done. Done many splines like that when I get a oddball or one I don’t have a hob for. Look up ansi b92.1 spline tables if you want to.

Sent from my iPhone using Tapatalk

pianoman8t8 · Jan 5, 2021

Turns out I have a 2nd shaft to make as well (qtny 3, same spline on both ends, would prefer gear cutter vs fly cutter). This one seems a bit easier to determine, at least to a non-expert on gears vs involute splines.
1.25" OD
14 Teeth
Flat root (actually it's more of a diameter-shape of the minor if that makes sense, likely due to it being hobbed)

Would a #7 gear cutter be appropriate for this spline? I'm still not sure a gear cutter is the same as a spline cutter?
McMaster 3034A735

EmGo · Jan 5, 2021

pianoman8t8 said:
would prefer gear cutter vs fly cutter.

No, Phil told you right, just make a fly cutter. It's easiest and most accurate. Gear space cutters are not anywhere near correct for splines.

One way that works is to take a piece of 3/4" bar for a shank (assuming you have a Bridgeport, if you can hold bigger it's better), then rough in your hss tool, about an inch and a half long, braze it onto the end of the bar with the tool bit aligned across the center, then finish grind to fit your sample. Hold up to light to match the shape, as suggested. This will give you a pretty rigid flycutter that will hold up okay and cut well. Will easily last for three parts. Maybe don't climb with it, though

pianoman8t8 · Jan 5, 2021

EG,
Thanks for the tips. Yeah I didn't know if the gear cutter would work for a spline? But that appears to be a no. I could either do it in the B-port, or in the Abene. I'll need to rig up a center support for the rotary either way, or find one on fleabay.

Turbowerks · Jan 6, 2021

Dont know if you have a tool grinder , but i have taken old angle cutters dull ,broken (read cheap) reground them to fit the spline takes time but work real nice but flycutter is the way to go for the amount of splines

Sent from my iPhone using Tapatalk

Search

Largest Manufacturing Technology Community on the Web

Search

Selecting involute spline cutter

pianoman8t8

Hot Rolled

Phil in Montana

Stainless

pianoman8t8

Hot Rolled

Phil in Montana

Stainless

Turbowerks

Cast Iron

pianoman8t8

Hot Rolled

EmGo

Diamond

pianoman8t8

Hot Rolled

Turbowerks

Cast Iron

Similar threads