The thread on millwrights got me to wondering about something.

I have seen one mill (I am sure mechanism was reconstructed) that
actually had wood crown and pinion gears (many mills required a right
angle change in shaft axis). And I see many diagrams of wooden gears in
history of technology books on mills.

Most gear sets I see are metal, from mid to late nineteenth century.

Now, I wonder if there was a complete, sudden transition from wood to
metal gears, or was there a transitional period with what we might call
composite gears- part wood, part metal.

For instance, we could have metal teeth mounted in a wooden wheel. That
to me would seem more reasonable than vis versa. Has anyone ever heard
of such a composite gear in a mill?

Don Stauffer wrote:
The thread on millwrights got me to wondering about something.

I have seen one mill (I am sure mechanism was reconstructed) that
actually had wood crown and pinion gears (many mills required a right
angle change in shaft axis). And I see many diagrams of wooden gears in
history of technology books on mills.

Most gear sets I see are metal, from mid to late nineteenth century.

Now, I wonder if there was a complete, sudden transition from wood to
metal gears, or was there a transitional period with what we might call
composite gears- part wood, part metal.

For instance, we could have metal teeth mounted in a wooden wheel. That
to me would seem more reasonable than vis versa. Has anyone ever heard
of such a composite gear in a mill?

Don,
I haven't seen any such but it does seem likely. It is not much
different from a steel-tired wood spoke wheel or pulley, both of which
were in common use. Except ... hmmm .. casting a gear ring would be
harder than bending a simple strip. Tractor wheel lugs (kinda'
tooth-like) were individually riveted on.

--
Fred R
________________
Drop TROU to email.

Don

I'd guess metal first showed up as strengthening brackets, bearing
surfaces and facings. Metal was darned expensive before the industrial
revolution. The reason finding a horse shoe is considered good luck is
you could take it to a smith and get tools made. You had to provide your
own material back then or buy it from the smith for high prices. Horse
shoes are made of good quality metal (people that could afford horses
were like modern Porsche owners, they didn't mess around with cheap
hardware) so they made great tools.

I was at a folk museum in Norway years ago and saw a hybrid set of gears
on an old grain mill. The large gear (about 15' in diameter that a horse
or two were attached to - on the inside of the gear oddly enough - it
had hinged pieces so the animals could be taken in) had replaceable
wooden teeth on the main gear and the right angle take off gear had thin
metal strap facing the sides of the wooden teeth. All the other gears
were wood (looked like some kind of dense fruit wood). My guess was the
metal was added for wear resistance. You could see the marks of the
metal strap on the big gear. The whole system was well worn and the wear
patterns matched so I don't think it was a replica.

In general, folk museums are worth going to. Some of the most amazing
blacksmithing I've ever seen was in a Hungarian folk museum.

Jim

Don Stauffer wrote:
The thread on millwrights got me to wondering about something.

I have seen one mill (I am sure mechanism was reconstructed) that
actually had wood crown and pinion gears (many mills required a right
angle change in shaft axis). And I see many diagrams of wooden gears in
history of technology books on mills.

Most gear sets I see are metal, from mid to late nineteenth century.

Now, I wonder if there was a complete, sudden transition from wood to
metal gears, or was there a transitional period with what we might call
composite gears- part wood, part metal.

For instance, we could have metal teeth mounted in a wooden wheel. That
to me would seem more reasonable than vis versa. Has anyone ever heard
of such a composite gear in a mill?

I've seen pictures of mill gearing where the teeth were wooden and the
bull gear itself was a cast iron "cage". I assume the tooth sockets
were tapered. The mill owner could then renew the teeth as they wore
out without having expensive tools, just simple wood working tools
would be all that was needed. The teeth would wear into each other,
too and bad meshes would eventually wear themselves in. Would be
farily quiet, too, compared to all cast iron gearing. I think the mill
itself was from the 1860s or so.

Stan

On 30 Aug 2005 11:10:18 -0700, wrote:


Don Stauffer wrote:
The thread on millwrights got me to wondering about something.

I have seen one mill (I am sure mechanism was reconstructed) that
actually had wood crown and pinion gears (many mills required a right
angle change in shaft axis). And I see many diagrams of wooden gears in
history of technology books on mills.

Most gear sets I see are metal, from mid to late nineteenth century.

Now, I wonder if there was a complete, sudden transition from wood to
metal gears, or was there a transitional period with what we might call
composite gears- part wood, part metal.


Yes, there is grist mill in Long Valley, N.J. that has a mix of
smaller all metal gears and large metal hubs with wooden teeth - less
noise and more on the spot repairable - but must importantly - Wood
on metal DOESN"T SPARK! In the dust ladent aireof a grist mill a
spark can be spelled B O O M!! No building!

wrote:
On 30 Aug 2005 11:10:18 -0700, wrote:


Don Stauffer wrote:

The thread on millwrights got me to wondering about something.

I have seen one mill (I am sure mechanism was reconstructed) that
actually had wood crown and pinion gears (many mills required a right
angle change in shaft axis). And I see many diagrams of wooden gears in
history of technology books on mills.

Most gear sets I see are metal, from mid to late nineteenth century.

Now, I wonder if there was a complete, sudden transition from wood to
metal gears, or was there a transitional period with what we might call
composite gears- part wood, part metal.



Yes, there is grist mill in Long Valley, N.J. that has a mix of
smaller all metal gears and large metal hubs with wooden teeth - less
noise and more on the spot repairable - but must importantly - Wood
on metal DOESN"T SPARK! In the dust ladent aireof a grist mill a
spark can be spelled B O O M!! No building!

Mixed wood and metal gear sets were used in sawmills for the same
reason. One variation used a composite gear with a cast iron 'cage' that
held wooden gear teeth. Normally this ran against an all metal gear.
Also, as was stated, many were of the bevel or crown gear type to
change angles between the shaftng.

Dan Mitchell
============