Posted: Sun May 03, 2009 5:37 pm
Bill,billmayo wrote:Since the single bearing quill shaft was not designed for the the second bearing, I find .001"-.002" differences in the shaft diameter (5/8") where the second bearing inner race rests/fits. Some go on easy and others a little harder. I use RED LocTite on the shaft to insure that the inner race will not turn of spin on the shaft. The machining of the housing for the second bearing must be precision and accurate. I did a dozen quill housings at a time so the machine shop will accept the work and give a good price. I have made use of the previous ones I had machined so may do another dozen in the new year. I do not sell these modified 2 bearing quills separately but only use them in the headstocks I sell because I give a warranty with them. This only applies to Poly-V drive Quills. Skip Campbell (10ER Guru) from Texas did sell a 2 bearing quill for the Gilmer drives.
Since I use one of my Mark Vs as a drill press and milling machine which puts a very high side thrust on the quill, I had a quill housing and shaft machined to accept the same size bearing directly behind the front bearing. This has worked well for me with no problems for many years now. I did a Gilmer drive at the same time too but as it cost twice as much for machining both the housing and shaft, I have not did any more.
Finally Note: I am finding that using the Fafnir 202KDD5 (C1 rated) bearing as the front bearing in the single bearing quills gives me excellant results (run out) as you get from the 2 bearing quill. Again, only my opinion.
Where do you buy your Fafnir 202KDD5-C1 bearings? I've only been successful in locating 202KDD5-C0 (standard) radial clearance.