Vintage Windmill and Wind Generator Forum

Hi -
On 2 separate properties within 20 miles of each other outside of Denver CO I've seen an Aermotor 702 with a vane that had a distinctly V shaped vane brace in that the end was pointy, not curved.

The Field Guide says the Pumping Aermotor had a V shaped brace but the drawing on the section head shows a curved V, or a narrow U. A photo on windmill-parts.com also shows a Pumping Aermotor vane with a curved V vane brace.

There's no lettering on either vane. I'm wondering if maybe a craftsman in the area made up these vanes? Or do some Aermotor vanes have pointy V vane braces?

The attached pic shows a later gear box, I'm figuring this got put on when Aermotor did the self-oiling upgrade.

Thanks in advance for any info.
Beverly Braid, Aurora CO

I have seen several like this up here in South Dakota and have the same question. Will be interesting to see who else chimes in!

Wow that's really interesting, now I know this is definitely a thing, altho what kind of thing remains to be determined.
The Field Guide specifically says the Pumping Aermotors had a V shaped brace. Maybe some Pumping Aermotor vane braces were pointier than others?
Thanks for your reply!

I have never seen any that I thought were original to open gears. The ones I have seen and the one pictured are after market. The wheel you have pictured is after market also. The 2 biggest after market rebuilders and builders and out of south dakota probably did not produce them. If they did, it was very short duration. There was a time that the original owners of Dean Bennett produced and rebuilt windmills. I think they may have produced them. I have seen them in CO, KS, NE, WY and SD so it was someone that had a distribution nerwork. .There is a very characteristic look to open gear vanes in the seaming and the corners that these don't have.

Ron Stauffer
Montrose CO

Thanks Ron, that was so helpful!

Here's a pic of two open gear Aermoter tailvanes. The bracing is rounded also.The swallowtail one is off the original 1888-89-early 90, the other is off late Bell Hub or model 99.

Thanks for confirming that the V brace on the older models is indeed not really a V but more of a U.
All these replies have been so very helpful and educational!

Additionally I'm finding some Aermotor 702s with completely blank vanes (a few have been on the ground so I can examine them closely, there's no faded lettering), and typical curved-V shaped vane braces.

I wonder if these perhaps came from a different rebuilder than the rebuilder doing the pointy braces. Interesting to speculate on the history of the windmill business!

Beverly

Part of Aermotor's success was the interchangeability of parts over a long period and this invited lots of aftermarket and clone parts. Vanes without lettering are likely aftermarket/clone. The quick litmus on these is the horizontal seam at the top back corner of a Chicago Aermotor on 8 & 10 vanes as aftermarket clones were one piece. Besides being one piece, a lot were galvanized sheet versus hot dip. Aermotor was more proprietary at one time so aftermarket/clones didnt have lettering.

Considering the age of golden era Chicago and older Aermotor, there are few that are entirely original. Most have been down for repairs or rebuild with parts replaced.

The above second pic of Dan's post is an example. The vane sheet is over 100 years old but is an early oil bath, not an open gear. Both the lettering logo and construction style are consistent with oil bath.

Ron Stauffer
Montrose CO

That pic of the second tailvane came off a model 99 Aermoter and the tailbone is a model 99 with the cast iron brackets.