13" threaded spindle nose sizes

[jmm03]

Hello all, a friend of mine has a 13" with a threaded spindle and has asked me to be on the lookout for a three jaw chuck. What thread size should I be looking for on the back plate? (if there are several different threaded spindles I realize that I will need to get him to measure the actual one he has, but I am just starting the search and am not sure of what to ask him to check, serial number, model number etc...) Thanks, Jim

 

[BKahler]

If it is a 13" then there are two possibilities that I now of. If the bore is 1" through the spindle then the spindle thread size is 1-7/8". If it is larger than 1" then I think it is 2-1/4" but I'm not 100% sure on that one.

The 1-7/8" threaded plates are hard to come by. Once in a while you can find them on ebay. It's been a while since I've had to look for one.

Brad

 

[johnoder]

For certain all of them from '46 back are 1 7/8 - 8

Or if it has the single tumbler QC gear box, it no doubt is that size..

A very quick test WITH CHUCK ON (and nothing in spindle bore) is to see if a bar of 1 1/4 or 1 3/8 dia. won't slide thru spindle it has the 1 7/8 - 8 nose

 

[MrWhoopee]

2-1/4 - 8 is the larger option, the bore is big enough for a 5c collet draw-tube.

 

[packrat2]

Let's hope your friends lathe has the 2 1/4-8 inch spindle nose, chucks are easy to find and like MrWhoopee said you can use 5C closer..

 

[MyLilMule]

You can find a partially machined back plate for the 1-7/8" - 8tpi spindle at CDCO tools.

 

[jmm03]

thanks to all for the help, he has the more readily sourced 2 1/4" thankfully. I turned him on to a variety of sources with suggestions. Jim