Splines on a dividing head?

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BT066

Aluminum

Joined

Sep 15, 2004

Location

Mass.

• Oct 28, 2004

• #1

During my apprenticship (decades ago) I worked for a mint. One job I had was creating graphite electrodes to burn (EDM) reeds into collars for coining. This required me setting up a dividing head and a small cutter on a bridgeport. I was splining the graphite. I haven't seen or used a dividing head since. Now many years later, I need to shorten an axle for a Hotrod. My question, is there a dividing head with a though collet (chuck) opening in the back big enough for say a 1.75 axle? Am I on the right track? Is this the proper proceedure to respline an axle? Does anybody have leads on a old dividing head? I see a couple on eBay right now but can't tell if they go through....thanks alot. BT

 

D

damonfg

Titanium

Joined

Apr 23, 2003

Location

Portland, ME, USA

• Oct 28, 2004

• #2

I think you may be better off to not go through the dividing head, just configure the shaft to be "on centers" - driven with a dog and mated to a tailstock on the mill table.

We do many that way, no constraint on the bore size. You can cut up to about a 20" long spline
on a 42" B'port table.

 

M

metlmunchr

Diamond

Joined

Jul 25, 2004

Location

Asheville NC USA

• Oct 28, 2004

• #3

Most car axles have rolled splines these days. The shape is tricky to reproduce and since they're fairly fine , like a 31 spline Ford for example, if the engagement into the side gear is the least bit sloppy it'll split the side gear. The second problem is most of the axles are necked down behind the spline and not big enough to recut anyway. There are a couple outfits in California that shorten and respline axles for way cheap prices. Can't remember the names offhand but they advertise in the small ads in the back of Hot Rod and Street Rodder magazines.

 

Forrest Addy

Diamond

Joined

Dec 20, 2000

Location

Bremerton WA USA

• Oct 28, 2004

• #4

Prep and machine the splines on the axle before you cut the axle to length. Or at least leave some extra length. This give you something to hang onto when you cut them.

You can check the size as you go by measuring the spline PD over wires.

 

D

damonfg

Titanium

Joined

Apr 23, 2003

Location

Portland, ME, USA

• Oct 29, 2004

• #5

1.75" sounds pretty beefy... What is it out of?

Plenty of aftermarket shafts today come as blanks and are cut to length and then splines are cut to suit. We see a set every couple of weeks or so.

 

B

BT066

Aluminum

Joined

Sep 15, 2004

Location

Mass.

• Oct 29, 2004

• #6

Thanks for the input all. I need to index the shaft accuratly, how would I do that between centers? The shafts do have centers already so this might work. The axles need to be cut way back to the body in order to re-establish the right diameter and respline.I know about places like Moser engineering, I want to offer the same service overnight delivery for cheap cash (barter?)in New England. Shipping a 9" Ford is murder. The axle diameter is under 1.75 I just wanted to know the maximum a dividing head could go through. There is alot of call for this here and I think it could be profitable for me to put many hours in my shop...but I keep turning people away. Thanks again! BT

 

johnoder

Diamond

Joined

Jul 16, 2004

Location

Houston, TX USA

• Oct 29, 2004

• #7

I've seen a photo of Currie (west coast) milling the spines on one of their after market 9" Ford axles. It was being done between centers, using carbide, with sparks every where, so you know the axle was being cut in the hard condition. They were just using the corner of a square insert - I.E., the splines looked like it - cutter sweep on one spline flank but not the other where the splines ended. The axles I bought from them were also cut like this. See my article a few years back in Street Rodder on bulkheading a nine inch.

John Oder

 

johnoder

Diamond

Joined

Jul 16, 2004

Location

Houston, TX USA

• Oct 29, 2004

• #8

You could eliminate the bulk and "iffyness" of a dividing head by making up a dedicated 31 spline indexer from a short section of C6 output shaft and its mating slip yoke. This spline is indentical to the 31 axle spline FWIW, and is also found on some of the HD five speeds, like the TKO.

John

 

D

damonfg

Titanium

Joined

Apr 23, 2003

Location

Portland, ME, USA

• Oct 29, 2004

• #9

I was gonna post a pic but then again since you're trying to compete with our business, I'll just say to ship em up the road a piece

 

M

metlmunchr

Diamond

Joined

Jul 25, 2004

Location

Asheville NC USA

• Oct 29, 2004

• #10

They were just using the corner of a square insert - I.E., the splines looked like it

Click to expand...

John, do they really just use the corner of an insert and make an approximation that will fit into the side gear spline? If so, now I know why it looks like they can do it so cheap.

 

B

BT066

Aluminum

Joined

Sep 15, 2004

Location

Mass.

• Oct 29, 2004

• #11

Whoops! Not trying to compete at all. No-one down here knows about you. Send me an e-mail and maybe I can send you some work. (untill I tool up!)

 

johnoder

Diamond

Joined

Jul 16, 2004

Location

Houston, TX USA

• Oct 29, 2004

• #12

metlmunchr:

Sure looked that way both in photo and actual part. Even though the post above talks about very close fits my experience is that they are a little loose, so maybe the geometry is being fudged on by these el cheapo processes.

I do know some of the bigger axles (40 and more spline - that I do not know if they are machined as crudely) are transmitting some really prodigious HP in the professional classes at the drags - at least for awhile.

OTOH, if you look at a factory rolled spline on an axle, it is certainly nothing to write home about as to quality.

John