tail stock will not eject

[RWasiczko]

Hello
I have a South Bend Model 9A lathe
when I use some centers and tools in the tailstock,
the tailstock will not eject the center when I have it
fully retracted
I would appreciate any suggestions
Thank You
Bob

 

[Bill Gruby]

Take the barrel all the way out of the tailstock and see if there is something in the tailstock stopping the barrel from retracting all the way.

"Billy G"

 

[RWasiczko]

the barrel retracts all the way in
almost flush with casting

 

[Terrywerm]

Hello
I have a South Bend Model 9A lathe
when I use some centers and tools in the tailstock,
the tailstock will not eject the center when I have it
fully retracted
I would appreciate any suggestions
Thank You
Bob

Bob, from what you have written, this problem occurs only with some of the morse taper items that you have. I would be willing to bet that the ones that give you trouble do not have a tang on the small end of the taper, and might even be drilled and tapped instead. If this is the case, you can make a 'tang' to fit from a short piece of threaded rod or a bolt that has been cut off to an appropriate length. A 9A would have a #2 MT if I remember correctly, so the threads that you find should be 3/8"-16. Once in a great while you may even find a Morse Taper tool that has no tang, but also is not drilled or tapped. You could probably drill the end and press in a short pin to use as a tang also. Try comparing the tools that give you trouble to the tools that do not and you should quickly see the difference.

 

[gjmontll]

Hi Bob,

I had a similar problem on my Logan 820, which also uses a MT2 taper in the tailstock. At least in my case, the cause is apparently that the Chinese mini lathes use the MT2, but in a non-standard manner, and they require a slightly shorter male taper. I know that Little Machine Shop sells both the standard and Chinese-compatible tooling. I imagine that other vendors do too.

See my photo here, the drill chuck is the Chinese short one, the live center has the proper, standard length. The difference is about 0.175. To fix the problem, you see that I JB-welded a nut to the end.


Greg

 

[Wreck™Wreck]

Hello
I have a South Bend Model 9A lathe
when I use some centers and tools in the tailstock,
the tailstock will not eject the center when I have it
fully retracted
I would appreciate any suggestions
Thank You
Bob

Add length to the tailstock leadscrew on the tool end, this will disloge every taper tool.
If you are concerned about modifying a classic lathe put a spacer in the taper before the tool, dime coins work well on small MT tapers.

 

[higgite]

I have a couple of "short" tailstock tools that don't reach the end of the T/S leadscrew. When I use them, I place a short piece of steel round bar in the barrel to fill the gap between the tool and leadscrew when it's cranked all the way in. It's easily removed with a magnetic screwdriver. A proper size ball bearing works as well. In a bind, you can just remove the barrel and use a piece of bar stock to knock the tool loose.

Tom

 

[Bill Gruby]

the barrel retracts all the way in
almost flush with casting

The only cure I know of from this point is a longer lead screw.

,"Billy G"

 

[Ulma Doctor]

to echo another post, (kinda)

i have a Hercus 9" SB Clone, and have the same issue on some tooling.
i simply cut a mild steel rod,1/2" diameter x 3/4",
and insert it into the TS bore before using the troublemaking tooling.
the rod piece pushes the MT2 tooling out really easily.
i retrieve the slug with a magnet when i need to take it out .

 

[f350ca]

When I redid my Hardinge I must have assembled the tailstock wrong the first time around. Same problem, would eject the drill chuck but not the live centre, but the ram appeared to be retracting all the way. Tore it down again and it worked, think the ram was bottoming out before the tread was all the way in, if that makes sense, the thread moves with the ram on mine. Might be worth a check.

Greg