Spindle Indexer

wa5cab said:
No. That is for the 1/8" dia. pin that gets installed after you slide the index pin through the hole in the headstock over the spring loaded ball. It just keeps you from accidentally pulling the index pin out of the headstock (and probably losing the ball and spring). There is no groove or ring for the ball. It just holds the index pin in position by friction.
Click to expand...

For exactly that reason of the pin not being locked in both the in & out position I turned two small grooves to locate the ball bearing to the pin to give it a better lock , as on one occasion I accidentally pushed the pin into the bull gear when I was fastening some thing to the face plate .
I didn't notice it till I tried to rotate the face plate by hand before starting the lathe up .
 
Round in Circles - the two grooves you mentioned make sense.

The index pin tip on mine is gone by prior owners. I don't know if I still have the ball and spring (my chuck needs to come off to extract pin). Not sure if I can turn the end down into a pin or not. The hole for the roll pin is still there, so turning the end would make it shorter. Perhaps put groove(s) for a c-clip(s) to hit the head stock so pin can't come out.
 
In 35+ years in service, I've never found any need for indexing grooves in the indexing pin.

I suspect that the pin will be too short if you try to turn down the end to make a new 0.125" dia. end. To begin with, you will have to cut off 0.162". Then turn down another 0.070" to 0.125". Then step over 0.100 and drill if for the retaining pin. Better to just make a new one from scratch or buy one from Clausing.
 
Robert my original pin was parallel , knurled at the tail stock end & it had a flat section cut out the middle where the bearing pressed against . It was easy to accidentally rotate the pin by accident and start it on its journey of coming out . The ball bearing didn't really hold the pin very well at all .
Another is to use the lathe to face the broken end of the pin up , center drill the end where the pin is missing and insert an interference fit new pin end , Perhaps even using some thread lock to hold it in place .
My indexing pin is in a flat bearing cap face with a pre drilled access & oil hole leading down to the ball & spring ( it's under a felt oil pad ) but similar to the one shown inthe picture
I played about for a while trying to get the ball & spring back down the hole and the indexing pin reinserted .

In the end to put the pin back in I turned up a blunt rounded nosed slightly tapered aluminium pin that also had a hole in the end to take to pointed tip of the indexing pin so it just slipped in the hole .
Slid it in to just past the hole for the spring and ball bearing , fiddled around with a small screw driver that I'd put a blob of grease on to get the spring in down the hole & the ball sat on the spring . Then used the screwdriver to gently press the ball down & slide the aluminium pin back to hold it all in place . That done it was really easy to reinsert insert the adapted indexing pin .

Had to go fishing with a blob of grease on a steel ruler to fish the aluminium plug out the bottom of the head stock housing .
 
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Well, OK. But the original pin in my 3996 has no flat on the side and has never moved from its position other than when physically pushed.

On salvaging the original pin with broken off end, I took some measurements on the intact one in my machine and concluded that it is not long enough if you cut it off such as to eliminate the cross drilled hole. When engaged, none of the pin is sticking out of the headstock to grab onto and disengage. And I don't think that there is enough length to the left of the original hole to face the end and bore it for the pin. Perhaps on the 10D and 10F, the section of headstock casting where the pin is located is thinner than on the late 12".
 
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