Originally Posted by
gcz
i've been following this thread about spindles and googling all over to learn about it myself.
what i seem to get is that the worst problem will be heat induced elongation of the shaft and consequent excessive loading of the bearings.
? - if the spindle chassis and the shaft are made of identical material, will this not obviate the problem entirely?
? - if each end of the spindle is in a roller bearing only, and a thin disk on the lower end of the shaft is captured between thrust bearings, then will not the thin-ness of the disk obviate any problem of elongation just simply because it's not very long?
obviously the smaller the diameter of the shaft, the faster it will max because the bearing travel will be proportionately shorter each rev than on larger diameter.
these look like good clues to start making a test spindle - anybody see flaws or something i overlook?
Hi gcz,
Now we really get into the meat of the problem/solution.
If you had a company that hired the engineers, did the research, the countless hours of testing various metal alloy expansion rates, developing theories, testing theoritical solutions, etc. and could manufacture a quality spindle that is stable and stays within tolerances required at say 1,000 -- 30,000 rpm then run sweetly for years with continuous heavy/light/no load cycles without a rebuild. Would that be worth something? Would you be able to sell it inepensively to a limited market? Would you share the information with the world? I think not. ebay really does rock!
The rest of us mortals must learn to live with compromise.
Mike
(Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)