"PrecisionmachinisT" wrote in message news:FaCdneJsu86j0sPSnZ2dnUVZ_uKdnZ2d@scnresearch. com...

"PrecisionmachinisT" wrote in message
news:27udnTzUMPgGFMDSnZ2dnUVZ_qednZ2d@scnresearch. com...

"Karl Townsend" wrote in message
...
...
Your mileage may vary but the above probably describes the vast majority
of
milling spindles out there today with a fairly high degree of accuracy.

Wow! You know..if you keep out of politics, you actually DO know
something. Do yourself a favor and keep on mechanics and off politics,
which you obviously dont have a clue about.


Do us a favor and quit breathing, ****head.

Btw..he is correct.

Gunner


PT, thanks for the great advice. I bought all the bearings on eBay,
way less than the local bearing house, and I got top of the line
stuff. You saved me money.



Okay great....now I need to let you know that my discription above was
incomplete almost to the point of being totally wrong.

In the case of the above face /face installation, IF a UNIVERSAL set is used
then you would also need to place a thin shim in between the pair of inner
races--only THEN can you add preload by setting them into a shallower cavity
in the quill cartidge or housing...alternatively, with a back-back set, you
would add a shim between the outer races instead...

In practice, there is usually a inner and an outer steel spacer thats placed
in between the bearing sets and they range in height anywheres from say
about 1/2in thick for a r8 spindle on up to about 4in thick where you have
60 taper....

At any rate, either they are the exact same height or else one of them is
say .0007 or so thinner than the other--you can surface grind these as a
set if you have a surface grinder, what you do is you take them both to a
cleanup and then you remove one of them and continue grinding the other (
which one to remove depends upon whether the actual set you are installing
is universal, back-back or face-face )...If you do this, then any set can be
used in any configuration you want as long as you check preload and properly
compensate...by clamping in a vise thus compressing the outer races in both
configurations and measuring the play (if any ) with an indicator or by
using some plastic-gage or even a piece of solder......then you can
tentatively install by setting up the stack in a manner that INTENTIONALLY
results in slop and check the situation by tapping the assembly back and
forth with dead blow oe a brass rod or similar.

Anyways, good luck...hopefully, I've provided enough insight here where you
can sucessfully finish the job if you think things through carefully as you
go along...

--if you have any other questions I'll try and help if I can but since every
bearing manufacturer seems to have their own numbering system then the
research and cross refrencing is going to have to be be up to you because I
simply don't have very much free time these days.


This one is a pretty good book

http://www.ebay.com/sch/i.html?_from...All-Categories

My copy is the 6th edition but as I understand it New Departure basically was the company that pioneered angular contact bearing technology and so it covers the basics fairly well starting from an era in time back before flush grinding was the norm and so it was absolutely imperative that proper measurements, shimming etc were undertaken.

--definately handy to possess an understanding of this stuff should you ever find yourself in a situation where you've obtained bearings of unknown lineage or where you've got no idea how old a spindle unit is or how the preset was accomplished at time of last bearing change because otherwise, if you just toss them in there then there's a significant possibility they will fail in a fairly short period of time.