I'm sure this has been discussed before (probably suffering from brainfade), but what is the downside of just reversing the lathe without the toolholder swinging up ?
I'm sure its theoretically a bad thing but I've done threads this way without apparent issue - I've even cut threads without using the compound by just forcing the tool in and doing repeated cuts, [hangs head in shame] (cos the compound was removed and I thought it would work and it did), although the thread finish was not as good as with using the compound.
So the tool gets rubbed backward by the work on the return - probably pushing the carriage as the leadscrew backlash will make it ineffective. The carriage (at least on my lathe) moves fairly easily, the work is soft, the tooling hard. As long as the tool is withdrawn on the last cut all the previous rubs will be removed anyway.
I'm not saying its desirable, but for cutting a few threads in a non production environment to me it seems a bit unnecessary unless the threads are so small and fine that the carriage load would cause issues.
If I've missed something please let me know what it is. Not looking to start a war here just trying to find out if the benefits are real or illusory.
All comments - especially the ones explaining my erroneous assumption - welcome.
Best Regards
picclock