Vintage Windmill and Wind Generator Forum

I'm a rookie when it comes to working on Dempster, so any help you can give me would be very much appreciated throughout my project. Do I need to weld up the gap between the turntable and the pipe stem bracket so it sits flush when it turns in the wind? See pic below. Thanks.

No. Just grind the bottom of the pipe shoulder flat.

Thank you sir!

Yep. Oh...Turntable info.....If you install 5/8 balls and it drags, cut or grind 1/8 or so off the cup. Most have a faint line you can see. Do the inner circle also. Leave the top half be, it's ok.

We've worked with Dempster repair for over 20 yrs. I live 40 miles from the factory (now closed) so the country is filled with Dempsters. There are two changes made during production of this mill. Pre 1931, !931 to 1952, From 1952 on. If substituting parts from another mill some parts may not fit or be needed from one era to another era. For example the bearing preload spring was eliminated after 1952 and shims are used for correct bearing preload. Also a front seal was added

If your mill is before 1952 and has the preload spring the tension between bearings may disguise the shaft wear under the front bearing. One mill we worked on the bearings appeared to be good when trying to get up/down play with fingers but the tension prevented that. But after disassembly the shaft was actually worn half way through because the bearing race locked up and the shaft was spinning in the race The front bearing almost always needs to be replace due to improper oiling. Remove the bearings to inspect the shaft. Read my article in the 2018 fall edition of the Gazette.

Another big problem of the early Dempsters was the front hub comes loose and wobbles on the shaft and ruins both hub and shaft. Later hubs have an extended shaft collar to help prevent this.

Windy Bob & Dave,

All great advice thank you so much.

Does the Dempster have a stamped year date on it like an Aermotor does on the inside? Thanks

Jerry

Jerry,

There is no date stamped on the inside of a Dempster gearbox. Early Dempster #12 windmills did have a year date put on the tail logo, but that stopped in the early 30s. Very late produced Dempsters also had a tag put on the outside of the gearbox. I've never seen an actual tag, but have seen late model gearboxes with the missing data tag.

As Dave indicates, seeing what kind of inside shaft parts you have, as well as the inner and outer hub, give a good idea of when it was produced.

Lance