Small Lathe Extended Point Live Center

[PJs]

Great build and write up Doug. It solves a source of needs & creative frustration in many ways, especially with that shallow taper prior to the point. Thanks also for all the details on materials and ops!!

On bigger lathes the OA length of a center like this is not a problem but on "peanuts (7x10-14) and micro's" every inch of travel counts. I've often thought of different ways of shortening the whole assembly, perhaps using thrust bearings or combo of thrust and angular contact. Holding the point solidly by its shank is the issue. In your case you have 2 5200's rated at ~7k N (~1600 lbf) each and More than adequate, but at 14mm width gives a probable 1.5" OA on the housing plus the point. Also a big part of the issue for peanuts is the difference between the MT2 shank and socket when seated has about a 1/4-3/8" gap. If one could turn a taper that fit further in to minimize that then shorten the live center part it would give valuable travel back.

Sorry for all this blah, ba, blah, just to ask your thoughts on reducing OA length and using needle thrust bearings with much higher dynamic rating, but I think its a good topic for others and your wisdom is Always appreciated.

PJ