10 ft Aermotor B702 & Dempster tower

[whyjay]

It’s been three+ weeks since my first posting in the Introduction section. I was slowed down by an inflamed tendon in my ankle/foot. Oh well it gave me time to research more about my recent purchase. Anyway just in the last few days I’ve been able to disassemble the blade sections and remove the gearbox. I believe the stamping indicates the gearbox was assembled November 1943. Next steps will be to disassemble the gearbox and order rebuild parts.

[windybob]

Yep, sometimes, life gets in the way. You are right on the date.

[whyjay]

Thanks for confirming the assembly date. I was told this was a working windmill when replaced with a solar setup. I disassembled the gearbox today. Didn’t look too bad bearing were definitely worn out. I’ll know more after cleaning.

[windybob]

702 Aermotors are one of the easier mills to rebuild, repair. Parts are not much of a problem, and they are engineered very well, most of the clearances are built in. 702 mills were put on the market in 1933 I believe. Very common even up untill now.

[whyjay]

Hello all, no photos yet but I did get the B702 motor guts and housing cleaned up. Took two mornings while it was cool, lots of scraping and a three gallons of Superclean, a bristle brush and lots of water but everything is almost touchable now. I have a rebuild kit on order but have a question about the guide wheel and hoop. I left both in place but the guide wheel seems a bit loose? How do you determine if wheel and/or hoop needs to be replaced? Second question: I know the lubrication oil is supposed to be 10w ND but is there a consensus about which brand of oil works best?

[Windcatcher530 Dan]

Luke I think your hoop and wheel looks fine to me there should be a little play . As far as the oil any brand should do.

[Ron Stauffer]

Judging from the trees and the grass you are in Palmer Divide area? If mill came out of NE and being a short stroke 10 , it likely was in the Sandhills?

If you can see or feel wear on the hoop, it can be welded and built up and ground smooth easier than removing/reinstalling. Guide wheel to hoop clearance at max 1/8.

There were years of 10 fan blades that liked to break in half. They started with hair line cracks out from the corners of the rectangular notch for the outer band. It being a single rivet wheel, I dont think you will see that but you should look. The B585 tailbone casting was never scaled quite right and likes to wear the eye socket

A 10 is much more long lived and durable than an 8 and the mast pipe is almost always good. Rebuild kits are more tho

Ron Stauffer
Montrose CO

[whyjay]

Thanks for the reply Ron. Good eye. Yes north side of the Palmer Divide. You set up a friend’s old windmill here locally.
I've got everything cleaned up and the case painted red primer now. Eighty years of grease and grime was a chore. I’ll check the clearance between the hoop and guide wheel in the morning. Meanwhile I have more questions. I spent time cleaning the tower mast area today. It’s the cup style mast and I just can’t figure out what goes between the bearing surface of the mast and the bottom of the gear housing. Ive seen mention of a plain steel washer and also a split washer? This rig had neither. Is there a a bearing in this stack somewhere?

[CTXmiller]

Part # 576 is a flat steel washer. The split washer (521) is something you could add without removing the gearbox completely off the mast pipe. They are wear items and act like a thrust washer and a spacer.