Cutting axle splines on a lathe?

[great white]

Howdy all.

I'm not what I would call a "machinist", but I can manage most of the things I need to make on my old atlas TH42. Mostly basic stuff.

But now I need to make some axles for my Argo. 8 of them. They look like this:



and the sprockets that go on them look like this:



put together looks like this:



(well, maybe not quite so greasy! Lol!)


All I've got is my atlas lathe. It does have a milling attachment.

The axle is pretty basic, but the issue is those splines.

I figure I could broach them, but that's 8 axles and 6 splines per. 48 splines. Yeesh, that will take forever.

So, is there a way to cut those splines on a lathe that isn't quite so labor intensive?

I don't mind doing repetitive procedures to get them done as long as the lathe is doing most of the grunt work.

If only I had a mill......

 

[Terrywerm]

Splines like that are usually cut on a horizontal mill, using a cutter with the correct profile. You could do it on your lathe, but most milling attachments are not robust enough to handle such a cut. It would also be difficult to properly index your axle for making those cuts accurately. I am not saying that it would be impossible, but it would be difficult.

 

[BtoVin83]

You have a 6 straight sided spline one of the easiest ones to cut. Some use two cutters and straddle cut the spline using a spacer between the cutters. I have always cut them by milling one side and then the other to get the proper width. Then use a end mill or cutter and mill out the material in between the splines. On some we actually ground a bottom cutter with a radius but not always, it is common to see splines with the flat bottom.

 

[BtoVin83]

The biggest issue will be indexing accurately, if that is off they won't fit very nicely.

 

[Alittlerusty]

You could use a horizontal milling cutter of the appropriate width mounted in an arbor held by the chuck or even an end mill in the chuck and either mount the axle in your milling setup or build a jig out of wood even to hold it on the bed. Getting the indexing right will be the hardest part

 

[great white]

You have a 6 straight sided spline one of the easiest ones to cut. Some use two cutters and straddle cut the spline using a spacer between the cutters. I have always cut them by milling one side and then the other to get the proper width. Then use a end mill or cutter and mill out the material in between the splines. On some we actually ground a bottom cutter with a radius but not always, it is common to see splines with the flat bottom.

on a lathe? or a mill?

 

[BtoVin83]

On a mill, 4'"Lucas, but these were large splines for air drills. Your milling attachment might be sturdy enough. I would try that long before trying to broach them as i'm not that young anymore and would run out of time I think.

 

[BtoVin83]

I searched for an Atlas milling attachment and it looks like you would use an endmill to cut each side of the spline then clear the middle out. Indexing would still be an issue. My dad got a patent on a gadget to put on shafts and used the center out of a protractor. set it at zero and level, then on the next spline move the protractor to the required angle and re-level by rotating the shaft.

 

[Eddyde]

I think it can be done, you shouldn't have too much problem holding the work in the milling attachment's vise, the biggest issue is indexing. Perhaps make hex shaped holder that can fit over a section of the shaft just behind the splined section and fixed with set screws. then its a simple matter of clamping the holder in the vise and rotating it to mill each spline.

 

[Bob Korves]

I searched for an Atlas milling attachment and it looks like you would use an endmill to cut each side of the spline then clear the middle out. Indexing would still be an issue. My dad got a patent on a gadget to put on shafts and used the center out of a protractor. set it at zero and level, then on the next spline move the protractor to the required angle and re-level by rotating the shaft.

Depends on the type of splines. If they are involute a form cutter will be required.