AL320G Half Nut

Kpar · Mar 30, 2020

Hi all, been absent for a while & now back. I've had the AL320g for a while now and just moving into threading, (with or without) the halfnut.
My question when I swing the thread dial out of the way there are two gib adjusting screws. Is this to adjust the half nut mesh , if so what would the procedure be to set this up ?.

awake · Apr 22, 2020

Kpar, I just stumbled across this post and see that you did not receive any answers. I don't know the lathe in question, so can't answer from direct knowledge. Can you post some pictures? If so, we can probably figure it out.

Kpar · Apr 22, 2020

Thanks Andy, Will take a photo next time up in the shed.
The manual supplied with the lathe is hopeless.
Kpar

Kpar · Apr 23, 2020

Andy, a couple of photos

Thread dial swung out of the way. Note the two adjusting screws, they don't seem to make any difference ?. I'm a little reluctant to move them too much as it might upset things.
Kpar

awake · Apr 23, 2020

Kpar, based on the placement, those surely must have to do with adjusting the half nuts, as you suggested above. I didn't have the foggiest notion of what sort of adjustment it might be, but I dug around on the internet and found what may be a manual for your lathe: https://images.machineryhouse.com.au/products/L141/PDF/L141 - Instructions Manual.pdf

If this is the right lathe, look at page 36 - you can see adjustment screws (parts 32 & 33) out to the side, and below the carriage you can see parts 50 & 51, which appear to go up into the carriage where the screws would bear. Part 51 is clearly the half-nut; 50 looks to me like a gib. From the picture, adjusting the screw would primarily affect the stiffness of the action (how hard or easy it is to move the half nuts) - which might have an indirect effect on the mesh, but it seems to me it would be fairly minimal. I would think the goal would be to adjust these screws until the half nut engagement and disengagement is smooth but not overly stiff - but that is just my guess, so take this with a dose of salt!

Kpar · Apr 24, 2020

Thanks again Andy. That L141 Instruction manual is far superior than the one I got with the lathe. I've now downloaded it and yes it is much clearer what the adjustments are for. Can't wait to have a go at it
Kpar