View Full Version : lathe concentricity
10-10-2001, 09:54 PM
Looking for articles or books that deal with ways of maintaining concentricity when doing lathe work. Thanks spinrow
10-10-2001, 10:18 PM
I don't understand your question. Unless a lathe is worn out, it naturaly machines true and straight. If you are having problems with out of round or taper, then the problem most likely will be in the machine. Lood headstock bearings, worn ways, crossfeed etc.
Can you give us more details?
10-11-2001, 01:58 AM
If I understand properly, you are talking about removal and replacement of work in a chuck or some other workholding gear?
In normal instances with pieces larger than 5C capacity you need to dial the piece in with a 4 jaw or Adjustable Super Precision Chuck (such as a Buck 6 jaw).
For 5C sized (1 1/16" max) or with a 5C step collet Hardinge recommends machining an emergency collet to required dimensions. This (In a HLV series lathe) will insure the same runout as the spindle (.000025 on an HLV) as long as the collet is not removed from the spindle. Maximum accuracy with Hardinge super accuracy collets is .0001 - still pretty good!
To insure concentricity on things like Morse Taper sockets you have to do the internal grinding while the piece is still mounted in the lathe.