[SEL] Sorta O/T..gear making

[Jim and Diane]

It seems unlikely to me that early engine people devised a unique gear
geometry.  This would have been a pretty demanding and expensive undertaking
and there would have been little if any advantage over what was already
invented. Almost surely these gears had a 14 1/2 degree pressure angle and
used an involute curve for the tooth form. There are other PA's in use today
and unless you are a real gear pro it almost impossible to eyeball different
pressure angles. There are also other tooth geometries besides involute, the
drawback is their shape makes them difficult to machine with no gain in
performance or life.

For gear terms see http://shopswarf.orcon.net.nz/spur.html

Jim

Jim and Diane Kirkes
Hemet, CA
jd.kirkes at verizon.net
----- Original Message ----- 
From: "Tommy Turner" <lcjudge at scrtc.com>
To: "The SEL email discussion list" <sel at lists.stationary-engine.com>
Sent: Wednesday, January 26, 2005 6:16 PM
Subject: Re: [SEL] Sorta O/T..gear making


> JB,
>
>     I've done the same thing several times with good results.  I've
> found it best to purchase  the crank gear and the cam gear and replace
> them both.  Some of the old timers had an odd ball pitch on their
> teeth.  I had a friend who needed a gear made and the guy who cut it for
> him had to have a special cutter ground to match the other gear.  Some
> of the real early manufacturers may have ground their own cutters and as
> a result, it was their own "design".
>
> Tommy Turner
> Magnolia, KY
>
>
>
> jbcast at charter.net wrote:
>
> >>What is the best route to take to get gear(s) made?  One is a
combination
> >>i.e. two gears, one casting.  I also need a smaller gear...all straight
cut
> >>teeth.  This is for manually traversing the carriage on my ole lathe.
Could
> >>the old ones be used for a pattern and is this something Rick Rowlands
could
> >>do?
> >>
> >>
> >>
> >Rick, get a Boston Gear or Rush Gear catalog, see if the gears are
available, width may be a little different, the center is adaptable also. On
my lathe I machined the hub and made a ring gear out of the new gear, heated
and shrunk it on and pinned it. On the double gear, if only one is bad, bore
it out amd press it on a shaft, bore the new gear and press it next to it.
> >J.B. Castagnos
> >Belle Rose, LA
> >
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> >
> >
> >
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