Quill bearing Burke Mil-rite

[BDriscole]

Well I have a plan. The lower bearings seems to be in good condition, so I'm going to repack them and use them. The with of the inner and outer rings on these bearing measure the same. I'm going replace the shim that came out when I disassembled it. Not really sure what it was doing, but someone thought it should be there so I'll replace it. For he top bearing I'm going to machine and install a pushing after I get the bearing in. I'm not saying this is the best plan, but its a plan within my set of skills and knowledge. If it doesn't work, I can always go to plane C. I'll keep you posted.

Bob

The old top bearing is MRC 206 SFF, I'm looking at McMaster-Carr is 6206-2RS (part # 6661K107).

6206-2RS

30

62

16

Steel

4,550

2,500

7,500

Lubricated

-30° to 210°

ABEC-3

6661K107

36.39

 

[Ischgl99]

Sounds like a good plan. I bought my upper bearing from McMaster-Carr, I used the shielded one, but the sealed bearing should work fine. The shim should have been between the two bearings on the outer ring so that when you tighten the bearing nut, it preloads the bearing. McMaster sells ring shims, but it doesn’t look like they have the right size for that bearing. You might need to experiment a bit to find the right thickness of the shim.

When putting the bearings on the spindle, it would be best to heat them up so that they slip on and don’t scrap off any metal on the bearing seat as they are being installed. An easy way to heat the bearing is to use a hot plate, but since you have seals on the bearings, you don’t want to place that side directly on the hot plate. To heat up the inner ring, you can make an aluminum stub shaft with one diameter slightly smaller than the bore, and then a larger diameter that sits on the hot plate. Once the inner ring gets to about 200-210F, it should just slide on, but you can go a bit higher. You don’t want to go over 250F to make sure you are not drawing out any hardness from the bearing. I also heard of people using a shop light and sitting the bearing directly on the bulb, but that will only work if you have incandescent bulbs, fluorescent or LEDs won’t work since they don’t get very hot.

 

[Beckerkumm]

You can also use a candleabra bulb to heat a bearing. I'm not sure shimming a deep groove with get you there but it is a cheap experiment. You want CN or C2 clearance, not C3. Dave

 

[Ischgl99]

You want CN or C2 clearance, not C3. Dave

Good catch, I was thinking about that but forgot to write it!

If he doesn’t shim the bearings, then there will be axial play and he’ll have poor rigidity. It might not be much better with the shim, and could be the reason for the chatter he experienced, but without, I think he will be disappointed.

 

[BDriscole]

Though I'd catch you guys up on my mill repair. Last weekend I spent a good part of Saturday trying to chuck the quill up in the lathe to cut it for a bushing. After several attempts, it keep walking out my chuck, I figured that my steady rest was not opening up enough. So I tried to open up the bolt slots on the steady rest. Could not get them to open enough. So on Monday I took to the local machine shop and had them install the bushing and bearing. Spent most of Tuesday getting it back together. Doing some cleanup and readjusting. Photo shows one pass. Prior to the work I would have had to make 2 or three following passes to get it this clean. Concentricity, for easy f typing, is +/- .001. That is better then when I purchased the machine. Bottom line I'm quit happy with the results. Thanks for your help.

Bob

 

[BDriscole]

I thought I would catch you guys up on my Mill repair. I spent most of last Saturday trying to chuck up the quill in my lathe to cut and install the bushing. After several attempts I could not the it in the chuck without it walking out of the jaws. Finally determined that the my steady rest was not open up enough to allow it to square up with the chuck. I even tried opening up the slots in the steady rest. I could not get it open enough. So I decided to pack it up and took it the a local machine shop on Monday to have the bushing and bearing installed. I got it back on Tuesday and after a good cleaning, greasing and adjusting of the parts, its now up and running again. I check the concentricity and for easy of typing its +/- .001". That's better then when I purchased it. Attached photo shows a good clean cut. Before repairs I would have had to make 2-3 following passed to get it that clean. Thanks to all for your help and suggestion.

Bob

 

[Ischgl99]

I’m glad to hear you got it back up and running better. I have about 0.001” runout on my spindle as well, when it comes time for new bearings, then I’ll worry about improving that.