Mark VII Quill bearing

[wannabewoodworker]

I was wondering if any of the brain trust hear knows of any issues with adding a second bearing to the quill housing on my Mark VII to make it into a 2 bearing quill thereby giving it extra support??? It looks as though you could easily install a second bearing on the back side of the quill housing where the splined shaft is just inside of the quill housing as long as a suitable sized bearing could be located??? What do you guy's think?? I am sure this has been thought about before but I thought I would ask to see if anyone has tried this before either successfully or unsuccessfully.

[billmayo]

I was wondering if any of the brain trust hear knows of any issues with adding a second bearing to the quill housing on my Mark VII to make it into a 2 bearing quill thereby giving it extra support??? It looks as though you could easily install a second bearing on the back side of the quill housing where the splined shaft is just inside of the quill housing as long as a suitable sized bearing could be located??? What do you guy's think?? I am sure this has been thought about before but I thought I would ask to see if anyone has tried this before either successfully or unsuccessfully.

Yes, other forum members and myself have done this. You need a machine shop with a metal lathe that has a 2" or bigger spindle bore to machine the back of the quill housing to accept the same size bearing as the front bearing. This needs to be centered and within .001 tolerance for the bearing. The quill shaft should have a 5/8" OD surface just in front of the splines to take the same ID bearing as the front quill bearing.

You can also add a second bearing just behind the front bearing that requires both the housing and shaft to be machined.

[wannabewoodworker]

Bill,
The guy who is doing my new cam measured the quill housing when I was there and he said that machining the inside of the quill backend would cut into the teeth on the upper outer surface of the quill housing. Another words he said there was not enough material to machine the inner surface of the quill housing. So what you are telling me is that you have machined the backend of the quill housing to accept the same size bearing as the front of the quill without any problems of cutting into the quill advance teeth????

Once you did this how did you retain the bearing in the housing???? I also assume that the bearing needs to be set up inside the housing quite a ways as the drive bushing seems to enter the backside of the housing somewhat.