Reassurance on 'Evolution' chuck made by Axminster

[Haggy]

I have been told by Axminster that their new 'Evolution' chuck will not detach itself from the lathe when run in reverse direction.  I have asked for a left and right hand thread to be machined into the chuck body so that it can be used both on the inboard and outboard sides - i am told it does not require the two holes for the 'locking' grub screws normally found on this chuck which  secure it to the headstock spindle.
I must be missing something, and can't see the logic, surely the chuck will unwind without the grub screws to secure it to the headstock shaft when the motor spins in reverse?  The answer I got was that 'Jason Breach' said it wouldn't come loose, I'm sure he is right but why?
 I would be very grateful if anyone could shed light on this matter.
       Many thanks- Haggy

[julcle]

I thought that the two locking grub screws were for this very purpose !
What is the M33 x 3.5mm (ref T38R) extended body with radial reverse locking ?
I must confess to not knowing much about these things but I am sure that a phone call to Axminster will explain the dilemma.

[Richard Findley]

Hi

If your chuck is threaded with both left and right thread it fits on a standard right thread inboard spindle (which won't undo under normal running) and a left thread for outboard which won't undo under normal running. It'll only undo by reversing the lathe in either situation.

I saw a picture on another forum that showed these locking screws as standard so can't imagine there will be a problem.

Hth

Richard

[Haggy]

Thank you for your help. 
The chuck I recieved from  Axminster arrived with no 'grub screw' holes  and was threaded for the outboard side of the lathe only.  Axminster were very good and collected the chuck the same day they deliverd it.  They told me they would remake the chuck but the  grub screw holes were not required. 
From reading your replies I think they are.  I can now be more confident when i get in touch with them this morning.  If this fails I may have to take George up on his idea of using glue.
         Haggy