# South Bend 9x36 mid 1930's



## Joseph (Nov 7, 2012)

The #2 taper in the tail stock will not hold the drill chuck when drilling, it will break loose and turn when drilling using  a 5/16 plus drill even with a sensible feed. I mounted the drill chuck in the lathe chuck using a 3/8 rod as to hold it, now able to use emery cloth to give the taper an even cleaning, swabbed the tail stock bore with paint solvent to remove any filings, this helped a bit but did not seem to seat the taper enough to hold well enough. Any suggestions as to help the taper seat better. Hmmm!,   I wonder if hand lapping with valve grinding compound would help. Thanks for any help.


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## tripletap3 (Nov 7, 2012)

Hey Joseph. I am no expert in this subject matter but I had the same problem with a older Atlas. It takes very little slipping of the taper in the tailstock to ruin the fit. I have heard that even one slipped rotation can damage the internal taper. You have to be very carefull that the arbor is seated correctly. I would first replace the arbor on the chuck and if that doesn't work I belive you may only be able to fix it by reaming the tailstock ram using a morse taper reamer.


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## Joseph (Nov 7, 2012)

tripletap3 said:


> Hey Joseph. I am no expert in this subject matter but I had the same problem with a older Atlas. It takes very little slipping of the taper in the tailstock to ruin the fit. I have heard that even one slipped rotation can damage the internal taper. You have to be very carefull that the arbor is seated correctly. I would first replace the arbor on the chuck and if that doesn't work I belive you may only be able to fix it by reaming the tailstock ram using a morse taper reamer.




Hello, Thank you for your quick response. I will try those two options, one at a time.


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## GK1918 (Nov 8, 2012)

Joe, first off this does happen time to time, what we do is put regular carpenters string line chalk on the
taper and then this will give you an idea whats going on.  Very find lapping compound i guess will help.
I had that problem on a no name 1920s big big drill press, and with nothing to lose I turned a taper
out of Alum. then stuck this (MT3) in a SB also MT3 and turned the thread for the chuck.  That was a
good 20yrs ago and still works perfectly.  My thoughts were a 100 yr old machines female taper is bound
to be a litle messed up so the aluminum gives a little crush slammed in with lead hammer.  A little tip is
turn this taper a little longer and keep fitting, and trimming the (end) until you get a good fit and it will
eject.  A fast way to turn this taper is chuck up anything then center drill it, then put a good known
dead center against tailstock then adjust compound will dial ind. until its zeroed (most dead centers are
center drilled).  Now with a piece of stock/center drill and turn a major dia and lenght for threads, turn 
it around and start turning the taper with compound rest method. Just trying to help im still not to good
with words        sam


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## swatson144 (Nov 8, 2012)

I had the same thing happen to me. Soft 2mt arbor and it galled the socket. I replaced the arbor with a hardened good quality arbor and borrowed a 2MT reamer now it all works perfect. The reamers aren't very costly and I was gonna buy one but my buddy has one so borrowed it was.

Really all you need to do to the socket is knock the high spots off, not ream to perfection.

Steve


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## Joseph (Nov 11, 2012)

swatson144 said:


> I had the same thing happen to me. Soft 2mt arbor and it galled the socket. I replaced the arbor with a hardened good quality arbor and borrowed a 2MT reamer now it all works perfect. The reamers aren't very costly and I was gonna buy one but my buddy has one so borrowed it was.
> 
> Really all you need to do to the socket is knock the high spots off, not ream to perfection.
> 
> Steve


 Thank you for your help, that's is another great idea.


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## Joseph (Nov 11, 2012)

GK1918 said:


> Joe, first off this does happen time to time, what we do is put regular carpenters string line chalk on the
> taper and then this will give you an idea whats going on.  Very find lapping compound i guess will help.
> I had that problem on a no name 1920s big big drill press, and with nothing to lose I turned a taper
> out of Alum. then stuck this (MT3) in a SB also MT3 and turned the thread for the chuck.  That was a
> ...



Thank you, do have some chalk, never thought of that, the Amish would come up with an idea like that, they are so resourceful. I will try it to see where their are any high spots using this method.


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## Metalmann (Nov 12, 2012)

Used to use 'Prussian Blue' for such jobs.


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