I had a huge problem with the lathe crashing itself during the initial usage of the threading wizard.  During the preparatory moves, the machine would rapid to a coordinate that wasn't listed in the generated code.  The only way to stop it was to edit out the G53.  I read the explanation of G53 but must admit my lack of understanding of proper G53 usage.  I forgot to edit it out last time I used it and killed a brand new threading tool (and a pair of not-so-new skivvies.)  Up 'til now my life has been just fine without G53 so I plan to edit the wizard to prevent it killing more tools or worse.

Having said all that, it must be there for a reason so can someone edumacate me as to why it's there and if it's needed to properly cut threads?  I'm getting decent results without it and I think the strange cutting characteristics I'm seeing are due to flex in the machine but I could be very wrong.

it's probably doing the g53 for a toolchange.

Ahh, OK thanks a/t.  It's too cold to venture into the shop yet but while piddling around with Mach on the house PC I may have stumbled across my dumba$$ "problem."  I always "Set Home X" home & "Zero World X" every time I start Mach but haven't been doing the same to Z since I haven't finished my Z home opto switch yet.  If I click "Zero World Z" after touching off the Z, things seem to work normally.  As usual, my problems are self-induced.

Warmed up enough to get out in the shop to double-check it on the machine itself.  Yup, that was it.  Sorry for the waste of bandwidth.

I do not like the G53 in the threading wizard as I do not want to go to machine coords zero to change tools. My tool change position is determined by the part I have in the chuck and not the machine coords zero.
 It however is simple to edit the macro to remove the G53 and once you do that the toolchange position DROs in the wizard will then reflect the work offset position which in my mind is much more suitable, especially if using a turret..
Hood

Thanks hood, your way makes sense to me too...macro now edited.