I think it is pretty standard for scroll chucks to not repeat better than 0.001". My experience is that chucks are often considered good in the 0.001" to 0.005" run out repeatability. I suspect when the chuck is tightened, there is enough friction between the jaws and the chuck body that prevents the movement in the scroll to body clearance you reference below.
I understand power chucks are more repeatable with their wedge clamping system. I suspect that comes from functioning in a way that is analogous to a collet chuck. Adam On 2015-06-05 08:30, andy pugh wrote: > On 5 June 2015 at 13:09, Erik Christiansen <[email protected]> > wrote: >> Isn't the scroll on a close-fitting spigot, annular to the centre >> hole? >> If that's so sloppy that it can rattle, then it would be pushed to >> eccentricity by the lathe tool. Time for a new chuck, then. > > It needs enough clearance to rotate, and that tends to mean at least > 0.0004" clearance. ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
