On Sat, 15 Feb 2014 15:55:25 -0500, "Phil Kangas"
wrote:
Guy showed up here the other day asking if I
could repair the table lead screw nuts for a
RF mill drill. ;)} They are brass and one was
stripped out and the other was almost there.
He got it from a school shop and looks like
it was bumped or dropped, maybe that's why
the nuts are like this. So, buy new ones from
Rong Fu. Nope, can't find anything on the net
he says so I looked but nope, none. They are
7/8 - 10 acme. Did a web search for them but
nope, none available!Huh? Anyone know of
a source this nut? It would be easier to weld it
to a flat bar to make the mill useable anyway.
Or spend time to make two of them on the
lathe. Time is money...
=============
see
http://www.amazon.com/Loctite-Form-A.../dp/B000WSEUII
As you likely know, standard for 7/8 is 6 tpi
and for 10 tpi std diameter is 1/2.
http://en.wikipedia.org/wiki/Trapezoidal_thread_forms
I can't even find a tap that size, and the 7/8X6 stds are c.
150$.
brass nuts in 7/8X6 are c. 50$us
http://www.amazon.com/dp/B004ZNUJMC/ref=biss_dp_t_asn
Here is what one guy did in a similar situation
http://mckgyver.pbworks.com/w/page/20654129/AcmeTap
FWIW delren or nylon may be better than brass
Some of the old time machinists books mention rebuilding a
lead screw nut by babbiting around the lead screw.
http://www.conquestind.com/babbitt.php
http://www.smokstak.com/forum/showthread.php?t=71468
the more modern version is epoxy/teflon trade name moglice
http://www.moglice.com/
http://www.practicalmachinist.com/vb...ebuild-148285/
snip
I've used Moglice 1000 (the Teflon-based epoxy) to cast
leadscrew nuts when I had my Mill/Drill. It wasn't that
difficult: I drilled-out the old nuts, sprayed epoxy release
agent (that comes with the Moglice kit) on the screw, and
made a set of dams for the ends of the nut (to keep the
epoxy in). I drilled three holes along the length of the old
nut to inject the Moglice.
snip
--
Unka' George
"Gold is the money of kings,
silver is the money of gentlemen,
barter is the money of peasants,
but debt is the money of slaves"
-Norm Franz, "Money and Wealth in the New Millenium"