Restoring a Old Bell Hub Aermotor Windmill
by Kevin Moore
Bell Hub Aermotor Windmill
Kathy with the old Aermotor in a pile
The main windmill shaft babbitt
Pouring new babitt for the Old Aermotor
Warming Parts on the wood stove before painting
the old windmill is all together
My grandfather always said that he would rather be lucky than smart or good looking. I have never been told that I was good looking, but Iím sure I have been told a number of times that Iím not very smart. I guess that means that Iím bound to be lucky.
If you read the story ďFinding of a Real GEM,Ē you know how I found parts of a GEM windmill and Bell Hub Aermotor windmill. Now that was a lucky find. This is the story of what happened after we brought home the goodies.
The Lucky Find
The Aermotor Bell Hub windmill was literally rolled into a ball when we found it. A tractor had dragged it about 500 yards. I donít know how they did it, but the tail had been pulled completely around between the spokes.
So Whatís a Bell Hub?
The first time you see an 1897 Model Pumping Aermotor windmill, you will see why it was nicknamed the Bell Hub. The large hub looks just like a bell. This hub was only used for a short time and is very distinctive.
First Thingís First
I first took photographs of everything. Later, the photos would prove to be helpful in recalling how the windmill went together. I then sprayed penetrating oil on all the bolts and nuts.
As I waited for the oil to soak in, I started to search for other parts. Reminding myself not to focus on the main windmill, I looked around for parts that might be hidden in the grass or dirt. Iíve been told that the little parts can be the hardest to find replacements for later on, so I made a careful search of the area. While searching, I uncovered a number of parts a few yards away.
Taking apart a twisted 100-year-old windmill can be hard work. Trying to reach inside the bell hub and hold the bolt head was an ordeal. Everything was so twisted it was difficult to work with. I avoided the temptation to start cutting off parts. Iím glad I didnít cut anything, as I needed the old parts as patterns to make replacement parts.
AJ had told me to ďtake everythingĒ when I find a windmill. My daughter wasnít familiar with AJís ďtake everythingĒ rule, and made a reference to ending up with a windmill junk pile. I corrected her, telling her that at worst, we would have a historical ďwindmill resource facility.Ē
You should also remember something else my grandfather told everyone: Whenever I helped my grandfather work in his shop, he would say, ďHaving Kevin help is like having my two best men not show up for work that day. Everything takes twice as long whenever Kevin picks up any tools.Ē
Good Friends to the Rescue
As soon as I got home, I posted a few photos on this site and the response was great. I was amazed at the resources that became available to me. Steve had a great parts diagram as well as a few close up photos of a restored Aermotor Bell Hub windmill. AJ and Mark helped to identify the model right away. Shane owns an Aermotor bell hub windmill, so he was an experienced source. Many others also helped with information and good ideas.
After power washing the windmill, I took more photos of it and started to take it apart. Upon disassembly, I found out the hard way that the pitman bolt on the large gear has reverse treads.
The hub was in good shape, but the main shaft was bent and the Babbitt was worn through.
Donít Break the Hub
I wasnít looking forward to getting the shaft out of the hub. It was held in place by a wedge key and 100 years of use. The bent shaft didnít help.
I ground off the end of the shaft and then put it in the press. Next, I made a jig to slide down over the shaft so I was pressing on the hub at the connection of the shaft. It didnít move.
I applied more pressure and heat and it still didnít move. The more we pushed, the more nervous I became. I needed a new plan before I broke the hub.
We put the shaft in a lathe and slowly milled out the center of the shaft. The idea was to provide a relief point for the keyway and shaft. Hopefully the shaft would collapse inward as we pushed.
Fold Slat A into Slot B
I had one V arm that wasnít bent too badly, so we made a jig out of scrap metal. We followed the original arm as closely as possible, using flat stock. It took a while to get the jig just right. The V arms bolted into the hub at an angle and twisted slightly.
Some Assembly Required
After sandblasting, all the windmill parts needed to be painted. I found that heating the parts in front of the wood stove helps the paint stick. Here is another tip: Donít let your wife come home and see you cooking windmill parts when you told her you would be cooking dinner.
I ordered the book ďHow I Pour Babbitt BearingsĒ by Vince Gingery. By trial and error, I ended up with a good pour. I repaired the pins with epoxy, as noted in my article Repairing an Old Aermotor Windmill
Honor Past Craftsman
At some point, someone replaced the original metal pitman arm with a wooden pitman arm. The workmanship on this wooden arm is outstanding. I felt obligated to replace the wooden arm with a nearly identical wooden replica. A friend, who is a true craftsman, took the dog-bone shaped part home and returned the next day with an identical wooden arm. I added bushing and thrush washers which I found online at http://www.buntingbearings.com
Although it went back together much easier than it came apart, it still took a great deal of time. I made new shafts and milled or drilled each connection or washer to provide a smooth running windmill.
I also added grease fittings so I can lube the windmill with a grease gun and scratched the Babbitt from the point of the grease fitting to allow grease to flow down the shaft.
The Aermotor windmill tail vane was the old style swallowtail with black lettering, so I spent a great deal of time restoring it. The Wheel required replacement.
I put the used Aermotor windmill wheel on in the shop just to test it out. Iím sure glad I did test it in the shop, because there is no way I could have done it on the tower! It seemed like everything was about half an inch out of alignment.
I found that my replacement wheel was out of round and the V arms did not allow for any movement. After a windmill wheel adjustment and careful alignment, I slowly tightened it up.
What Happens When You Pull This?
The Aermotor furl system was not together when I found the mill and I didnít have a clue as to how to make it work. After laying it out on the kitchen floor twenty times, I finally realized I was missing a part. A few e-mails later, I made a furl disk that worked.
Slap It Up!
I was able to salvage the top few feet of the original tower; we just added a little angle iron and put it up. A small adjustment to the furl system was needed, but all in all, it went well.
I didnít restore this windmill by myself. My great friends Rick and Ray were with me all the way. Many others provided a great deal of information. I would like to say a special thanks to Steve Storm, Shane Spangler, Mark Nice and AJ for all the information and support.
At the end of the day, it looked like this!