# How Do They Make Splined Axles?



## Grandcheapskate (Jan 5, 2006)

I was wondering how splined axles are made.

Does the splined section of an axle have a larger O.D. than the smooth sections of the axle? To me it seems this is true. If so, that would indicate the whole axle is splined and the sections which line up with the axle holes are somehow smoothed out.

Or is the axle cut from smooth stock and then the splines are cut? This would make the smooth sections of the axle the same O.D. as the splines.

Thanks...Joe


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## Top Down (Oct 30, 2009)

(Talking about HO here.) The act of making the splines pushes material out and up from the 'cuts', causing the peaks between them to be raised higher than the original dia. of the axle.

Not the same process as a 1:1 splined axle.


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## Grandcheapskate (Jan 5, 2006)

Top Down said:


> (Talking about HO here.) The act of making the splines pushes material out and up from the 'cuts', causing the peaks between them to be raised higher than the original dia. of the axle.
> 
> Not the same process as a 1:1 splined axle.


Great. That's what I wanted to know.

Thanks...Joe


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## smalltime (Jun 3, 2006)

Grandcheapskate said:


> I was wondering how splined axles are made.
> 
> Does the splined section of an axle have a larger O.D. than the smooth sections of the axle? To me it seems this is true. If so, that would indicate the whole axle is splined and the sections which line up with the axle holes are somehow smoothed out.
> 
> ...


The splined areas are actually called "knurling".

It is done on a metal lathe, in an action that doesn't cut, it moves material. Most knurling is done with two hard steel wheels that make a diamond pattern on the O.D. of the work piece. This particular patter is simply a straight line. The axles are smooth, and the application of the knurl is placed only where it's needed, then they are cut off and heat treated.

https://www.youtube.com/watch?v=nsCiVpi6qAk

Hope this helps.


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## rdm95 (May 8, 2008)

Splines are cut..Knurls are formed


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## Grandcheapskate (Jan 5, 2006)

smalltime said:


> The splined areas are actually called "knurling".
> 
> It is done on a metal lathe, in an action that doesn't cut, it moves material. Most knurling is done with two hard steel wheels that make a diamond pattern on the O.D. of the work piece. This particular patter is simply a straight line. The axles are smooth, and the application of the knurl is placed only where it's needed, then they are cut off and heat treated.
> 
> ...


Fascinating video. Having never worked in a machine shop some of the video went over my head and I will probably have to look at it a few times to get a better understanding of the process.

It does not appear to be a quick and/or inexpensive process. Amazing such a process would be done for millions of HO axles during the Aurora years and for all the years that followed.

Thanks...Joe


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## smalltime (Jun 3, 2006)

rdm95 said:


> Splines are cut..Knurls are formed


That's what I said.


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## LDThomas (Nov 30, 1999)

The splines are rolled on. Here is an example of a machine that can spit out parts by the zillions.

http://roto-flo.com/?gclid=CIS9q4vGhMwCFQEJaQod_JgBuw


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## vansmack2 (Feb 9, 2012)

LDThomas said:


> The splines are rolled on. Here is an example of a machine that can spit out parts by the zillions.
> 
> http://roto-flo.com/?gclid=CIS9q4vGhMwCFQEJaQod_JgBuw


Good video.


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## Grandcheapskate (Jan 5, 2006)

LDThomas said:


> The splines are rolled on. Here is an example of a machine that can spit out parts by the zillions.
> 
> http://roto-flo.com/?gclid=CIS9q4vGhMwCFQEJaQod_JgBuw


What software is needed to play an MP4 file?


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## Dushkwoneshe (Apr 27, 2012)

Grandcheapskate said:


> What software is needed to play an MP4 file?


This is the same one in a .wmv file (windows movie maker file), Grand... 

Should be no problem...

1*:*08 ...

*https://www.youtube.com/watch?v=oa58Uvweh34*

John
.


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## sizzlerjoe (Nov 21, 2009)

*how are axles made*

I would wager if someone wrote the tv show, 'how it's made' they would make a show of it. just make sure tell them they are toy axles and of what kind of vehicle. scale too.


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## Grandcheapskate (Jan 5, 2006)

Dushkwoneshe said:


> This is the same one in a .wmv file (windows movie maker file), Grand...
> 
> Should be no problem...
> 
> ...


Thanks. That is a much simpler process than the knurling in the earlier video.

Joe


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## smalltime (Jun 3, 2006)

Grandcheapskate said:


> Thanks. That is a much simpler process than the knurling in the earlier video.
> 
> Joe


It's the same thing.

That's simply a "high tech" knurling machine. It's very cool, but still a knurling operation on steroids.

Splines are CUT into the parent metal with a milling cutter similar to a gear hobbing machine. There is no cutting happening in the video.


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## Dushkwoneshe (Apr 27, 2012)

.
I think a lot are just pinched*/*stamped... No material removed,
just displaced...

John
.


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## Grandcheapskate (Jan 5, 2006)

smalltime said:


> It's the same thing.
> 
> That's simply a "high tech" knurling machine. It's very cool, but still a knurling operation on steroids.
> 
> Splines are CUT into the parent metal with a milling cutter similar to a gear hobbing machine. There is no cutting happening in the video.


Agreed. I can see there is no cutting or removal of material on the HO axles because the knurled area is a slightly larger diameter than the base axle. So the material must simple be "moved" to create the grooved areas.

Thanks...Joe


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## alpink (Aug 22, 2010)

there are elves in the wide wood
they bend metal with their minds when not making cookies
all splined axles come from the elves in the wide wood


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