Dempster #01201N Main Shaft Rebuild

[windybob]

Pin the spiral to the mainshaft. Slide the spring on and the binding washer. Heat the washer to swell it, and push the mainshaft from the other end in a loose vice till the binding washer shrinks and holds. If it's a 6 ft, install all the back end except the last pinion. If it's an 8 ft slide the shaft in the case, putting the pinions and bearing and spacers on inside the case. Then you can assemble the front part. MAke sure you test fit everything first, and check alignment with everything and bull gears before buttoning things up. On a 6 ft, the spacers inside the case are different. On a 8 ft, they are equal.
I am assuming you have the new race in the case bridge.

[JBarker]

Pin the spiral to the mainshaft. Slide the spring on and the binding washer. Heat the washer to swell it, and push the mainshaft from the other end in a loose vice till the binding washer shrinks and holds. If it's a 6 ft, install all the back end except the last pinion. If it's an 8 ft slide the shaft in the case, putting the pinions and bearing and spacers on inside the case. Then you can assemble the front part. MAke sure you test fit everything first, and check alignment with everything and bull gears before buttoning things up. On a 6 ft, the spacers inside the case are different. On a 8 ft, they are equal.
I am assuming you have the new race in the case bridge.

Windy,

Thanks for info, I think this is a 6ft mill isnt it? 01201N is the case #. I have the spiral pinned onto the main shaft now.
Also, I thought the binding washer went one after the front bearing? Im confused some, please let me know Dempster jedi master. I dont want to screw this up. I hope these arent stupid questions....lol
Thanks.

Jerry

[windybob]

Haha fooled you. I made up the name "binding washer" to make you think I was smart. LOL

Anyway, that washer goes up to the spring. Hope you marked it on the shaft before you took it off. I believe it also sets the front bearing distance from the front of the case.
The bearing goes on in front of it, and depending on the bearing number you use, a spacer washer also. ( the spacer washer first if it's a new style bearing) WHen the shaft is installed in the case, the outside race will go in over the bearing, and the setscrew should go up under the snout to lock in the race. Well, it goes in to keep the race from coming out, so you should see the setscrew before the race. ( it doesn't actually bind it,it blocks it.) The guide rod over the inside bearing race actually binds that one in.

On a 6 ft mill, as yours is, the outer pinion can pass thru the snout, but if you left the snapring in the inner race bore the last pinion won't pass thru the bore. That's why you can assemble most of the mainshaft before installing. You can't do that on a 8 ft. Also, on those barrell spacers next to the inner bearing, the longer one goes to the back , or between the last pinion and bearing..

PLEASE tell me the number on your bearings. It's important.

[Dave Straub]

The 8' Dempster bearings are Timken cup # 1931 and cone #1985 and are are readily available. The 6' Dempster bearings are Tinken cup # 1729 and cone # 1751. The cup is readily available however the cone is out of stock at Timken and many bearing houses are out. If you do find one expect to pay big bucks. Dempster recommended a change to use Timken bearing # 1779 with cup 1729. The thickness of 1779 is thinner than 1751. You will need to add a washer for each bearing .175 thick x .937 ID and 1.5 OD to = thickness of 1751. I found washers at an Implement store with .937 ID and .175 thick and had them turned down to 1.5 OD.

[windybob]

That's why I was wanting his bearing numbers.

I save everything off old shafts. I make spacers from bearing cone races. Many thicknesses for a variety of applications.

Also the short oil spirals are great for making pumprod guides for WB mills. That's when I change over old design to new design oil seal.

[JBarker]

Haha fooled you. I made up the name "binding washer" to make you think I was smart. LOL

Anyway, that washer goes up to the spring. Hope you marked it on the shaft before you took it off. I believe it also sets the front bearing distance from the front of the case.
The bearing goes on in front of it, and depending on the bearing number you use, a spacer washer also. ( the spacer washer first if it's a new style bearing) WHen the shaft is installed in the case, the outside race will go in over the bearing, and the setscrew should go up under the snout to lock in the race. Well, it goes in to keep the race from coming out, so you should see the setscrew before the race. ( it doesn't actually bind it,it blocks it.) The guide rod over the inside bearing race actually binds that one in.

On a 6 ft mill, as yours is, the outer pinion can pass thru the snout, but if you left the snapring in the inner race bore the last pinion won't pass thru the bore. That's why you can assemble most of the mainshaft before installing. You can't do that on a 8 ft. Also, on those barrell spacers next to the inner bearing, the longer one goes to the back , or between the last pinion and bearing..

PLEASE tell me the number on your bearings. It's important.

The original ones are #1751, they look like they are in good shape....Jerry

[windybob]

ok. don't need the spacers then.

[JBarker]

Pin the spiral to the mainshaft. Slide the spring on and the binding washer. Heat the washer to swell it, and push the mainshaft from the other end in a loose vice till the binding washer shrinks and holds. If it's a 6 ft, install all the back end except the last pinion. If it's an 8 ft slide the shaft in the case, putting the pinions and bearing and spacers on inside the case. Then you can assemble the front part. MAke sure you test fit everything first, and check alignment with everything and bull gears before buttoning things up. On a 6 ft, the spacers inside the case are different. On a 8 ft, they are equal.
I am assuming you have the new race in the case bridge.

Ok, Windy what do u mean by a loose vice to compress the spring??? You have a pic of a loose vice to use? Thanks

[windybob]

A vice that is not tight on the shaft. To slide through.

[JBarker]

Any tips on getting the spring compressed more on the shaft??? I still need to go 3/4 inch more. Thanks

Windy, I dont understand what a loose vice is you are recommending...sorry I know Im being stupid.