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Original Mark VII Upgrades

Posted: Sun Aug 09, 2015 11:38 am
by Steamdragon
I have some more questions before I start Frankensmithing my old Mark VII set up. Do any of you know what Mark V parts are direct fit for the old Mark VII. For example there has been discussion regarding the two bearing spindle being a better design than the old ones. Are the newer bearings a direct fit or would that be a waste of time? Any thoughts on how to update the old girl would be greatly appreciated.
I really like the reversing motor and the adjustable rack gear set up and the double tilt table.

Re: Original Mark VII Upgrades

Posted: Sun Aug 09, 2015 3:53 pm
by JPG
Steamdragon wrote:I have some more questions before I start Frankensmithing my old Mark VII set up. Do any of you know what Mark V parts are direct fit for the old Mark VII. For example there has been discussion regarding the two bearing spindle being a better design than the old ones. Are the newer bearings a direct fit or would that be a waste of time? Any thoughts on how to update the old girl would be greatly appreciated.
I really like the reversing motor and the adjustable rack gear set up and the double tilt table.
The Mark VII quill shaft is shorter than the Mark V.

IIRC, the quill body is also a different length. EDIT = Recollection incorrect! See post below.


It may be possible to modify a Mark 5/V two bearing quill, but IMHO not worth the effort. That from one who sees minimal advantage to the two bearing quill. Better, yes. Way better? . . .

Re: Original Mark VII Upgrades

Posted: Sun Aug 09, 2015 4:43 pm
by JPG
The quill splined shaft is slightly longer on the MV.
QUILL MVII - MV TWO BEARING A.jpg
QUILL MVII - MV TWO BEARING A.jpg (519.34 KiB) Viewed 833 times
Note the difference in the coupler. Drive shaft 'nest' the same dimensions but no retaining spring on the MVII. Quill shaft splines are shorter on the MV coupler.
QUILL MVII - MV TWO BEARING B.jpg
QUILL MVII - MV TWO BEARING B.jpg (460.88 KiB) Viewed 833 times
Both will pass into the MV quill body, but the MV coupler drags slightly on the MVII quill.
QUILL MVII - MV TWO BEARING C.jpg
QUILL MVII - MV TWO BEARING C.jpg (412.3 KiB) Viewed 833 times
I think it could work with shortening the splined shaft, and retaining the MVII coupler. The drive shaft is slightly different requiring the MVII coupler.