Take up nut on back of spindle

cannonmakerken

H-M Supporter - Gold Member
H-M Supporter Gold Member
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Jul 20, 2016
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I Bought an
Old 13 inch South Bend lathe and the take up nut on the rear of the spindle was broke so I purchased a new one from Grizzly Tools but the new one won't fit on the spindle so how can I fix it so it will screw onto the rear of the spindle.Was it machined wrong thanks.
 
Was it sold as a replacement part specifically for a 13" South Bend? They were made for many years, perhaps specifications were changed; contact them and ask questions. Unless you have another lathe, its not going to be easy to fix. Question; is the thread pitch the same as your spindle, but just too small to thread on? If so, the nut, if split for clamping will have to be provided with a spacer so that it will not collapse when re machining, and very carefully chucked up for rethreading, also you would need to make a thread gage to the same dimension of the threads on the spindle; this needs to be accurate, the spindle measured with wires or a thread micrometer and the gage carefully and accurately threaded, then, using an internal threading tool, the existing thread would need to be enlarged to fit the gage, and if the thread is very much undersize, it may need to be re bored on its minor diameter before threading.
First I would determine how much too small it is, if it is a very small amount you might be able to wedge into the split and open it up a small amount and be able to thread it onto the spindle.
 
Ok I'll measure in id of the new nut and the thread on the back of the spindle the new part is cast iron I think so if I wedge it I'll be careful thanks for the info.
 
well i put a wedge in that take up nut on my 13inch south bend lathe and it worked fine thanks for the information it helped
 
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