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Dempster #01201N Main Shaft Rebuild

Posted: Sun Jan 27, 2019 9:49 am
by JBarker
Ok, you Dempster experts. Any last minute advice and/ or tips before I reassemble the mainshaft? This will be my first. Thanks

Re: Dempster #1201N Main Shaft Rebuild

Posted: Sun Jan 27, 2019 12:10 pm
by wind fab
j barker
guessing you are replacing bearings?

Paul

Re: Dempster #1201N Main Shaft Rebuild

Posted: Sun Jan 27, 2019 12:36 pm
by JBarker
I havent yet, thought the old looked good but I'm not sure.

Re: Dempster #1201N Main Shaft Rebuild

Posted: Sun Jan 27, 2019 4:57 pm
by grezmonki
Is it going to pump water or is it for ornamental purposes?

Re: Dempster #1201N Main Shaft Rebuild

Posted: Sun Jan 27, 2019 6:43 pm
by windybob
Gee don't forget the little square keys for the pinions.

Re: Dempster #1201N Main Shaft Rebuild

Posted: Sun Jan 27, 2019 6:46 pm
by JBarker
This will pump water

Re: Dempster #1201N Main Shaft Rebuild

Posted: Sun Jan 27, 2019 6:55 pm
by windybob
Add to, or replace the seal felt in the front plate. You can't put too much felt in. Oil it also. There should be a setscrew under the snout with a locknut on it. This keeps the bearing race from coming out the front. Also, inside the snout, at the bottom where the bearing race goes, there is a cast 'bridge' covering the oil return drain. Make sure it's open under the 'bridge'. I have seen castings where it's nearly closed, I've had to knock the excess cast out. Rollers from bad bearings are wonderful for jamming it shut also.

Re: Dempster #1201N Main Shaft Rebuild

Posted: Sun Jan 27, 2019 8:50 pm
by JBarker
Windybob....where do u get felt?

Re: Dempster #1201N Main Shaft Rebuild

Posted: Mon Jan 28, 2019 7:52 am
by windybob
Might try Hobby Lobby or something.

Re: Dempster #1201N Main Shaft Rebuild

Posted: Thu Jan 31, 2019 11:22 pm
by Dave Straub
I should also mention that the mast pipe can wear through where it rubs on the platform bearing. When this happens the head will fall off to the side and the pump rod is all that's hold it from falling to the ground. Also wear will be seen at the storm stay area. We make and replace many mast pipes.

Windy does the same as we do on grinding down the platform bearing race if new balls still won't allow clearance. I hold the race along side of my chop saw blade and walk it around the blade to give a good even grind. Put in the new balls and check clearance. We also install a press in zerk on top. There is a small flat spot to drill. Use a 3/16" bit half way, then a smaller bit the rest of the way. But this metal is extremely hard. Takes special bits. Have the hole come through not in the valley of the groove but up always on the side. Don't mix upper and lower races as production can vary. A good fit will be when there is no side wobble. I haven't been able to find 90 deg. press in zerks. Forget trying to thread the hole for threaded zerks. I now use a 90 deg side adapter for my grease gun. I'm starting to now use water repellent marine grease sold at Menards. I buy new grade 25 balls at the Ball Bearing Store on E bay. Always buy about 100 or so at a time Use 15 balls not 16.