On 4/9/2012 8:01 AM, Viesturs Lācis wrote: > 2012/4/9 charles green<xxzzb...@yahoo.com>: >> i wonder if there is any math out there on the ideal taper form, given its >> use in specifed materials and load conditions? > Ohh, conical fits (I hope that is the correct translation) is the > thing we have been discussing in university lately. > Answer to Your question is: No. Because You skipped another (and IMHO > the most important) factor: specific use-case also applies. > What I mean - the angle of taper determines: > 1) how well both parts are centered each to other - the smaller angle, > the better centering; > 2) how much will the distance between bases of both cones change as > the surfaces of cones wear off - the larger the angle, the smaller the > distance, > tolerances on each cone also will increase the tolerance of the fit > dimensions for smaller cone angle values; > > So larger angle improves one, the smaller angle improves the other, so > the optimum value lies somewhere inbetween, changing in different > situations. That is why there is not the one and only answer (which is > also my answer to Your original question). > The way I see it now is that the load and material will determine > mostly the diameter (and length) of the taper, but the application of > particular mechanism (required precision of assembly etc) is the main > factor to determine the angle value. > > Viesturs > >
Nice argument as far as it goes, Viesturs, but it doesn't address what I was taught lo these many years ago by a practicing machinist and which I find echoed in my Machinery's Handbook. He divided the world of tapers into two classes: self-holding and self-releasing. The self-holding tapers have small enough angles of taper for friction along the tapered surface of the joint to reliably resist the torque transmitted from the tool. That same friction makes it difficult to release the taper from its socket. The self-releasing tapers have large enough angles of taper to allow easy removal but require some other means to lock the taper in place so it won't slip when torque is applied. Presumably only the self-holding tapers would be subject to the kind of wear you mention in 2). I suspect the differences within this class were due as much to the need to work around patents as to any thought of optimization. As for the discussion about the varying angles of taper on the various Morse tapers, concensus of the sources I read is that Morse just wasn't that good with his metrology. Once a mistake is propogated into practice through industrial standards, it takes on a life of its own. Regards, Kent ------------------------------------------------------------------------------ For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
