Gear lever not engaging

[Dr Stan]

(12-02-2016, 07:05 AM)aRM Wrote:

(12-02-2016, 03:27 AM)Pete O Wrote: As well as rotating the spindle by hand, try also rotating the leadscrew by hand as you engage the gear. Also, have you tried selecting the problem gear with the other levers in different positions? I think that if all of these suggestions don't help, the problem is likely something other than just the gear teeth not lining up.

Just spoke to the lathe supplier as well, who says the SPLINE SHAFT is broken 'cos we usually did not stop the Machine at the end of the thread run before engaging Reverse, which we were (incorrectly) doing all along.    He says we all do that and that's what causes the SPLINE SHAFT to break.    We always threaded from the Tailstock end towards the spindle and seldom used our Footbrake. He said that was why the Brake was there  !!!  And we always thread with the HALF-NUT fully engaged all the while - unlike how U Guys do it.

Do you have the machine manual including an exploded view?  If not get back with the supplier and get one as it will assist in the tear down & reassembly.  An additional technique is to take pics of the tear down piece by piece.

BTW, for internal threading I typically run the spindle in reverse with the threading tool upside down on the back side of the bore going from the bottom of the bore toward the tailstock.  Helps to virtually eliminate internal threading crashes.

I also either use the DRO or a travel indicator to set "0" at the bottom of the bore and make an internal groove in which to start the thread.