Missing a bit from the leadscrew?
Posted: Sat 15 Apr , 2023 11:45 am
I've been 'playing' with printing myself some gears and in the process I think I might be missing a spacer washer / bush as I seem to have a friction interference fit rather than a smooth and free fit.
In the gear side of my lathe, I have the shaft which holds the screw gear - an one piece item that also has the 8TPI thread that drives the main apron. There is some horizontal 'play' in this shaft, in that I can move it laterally about 1mm or so. When it is pushed in towards the headstock, the face of it goes past the face of the 'bush' it is mounted through. Thus when I put the existing 100T gear I have on there, there is metal to metal contact, moving to static, gear to lathe body - this is clearly incorrect and will only lead to wear / friction / heat / /additional strain etc.
On the Stud Gear arrangement, I have 2 keyway washers / bushes, one inboard and one outboard - should I have something similar on the main screwgear shaft such that it is small enough to sit within the static area but large enough to provide a mating face for the screw gear when it is fitted (or spacer bush depending on gear arrangement etc).
Pictures paint etc - you should be able to work out what is what from these:
In the gear side of my lathe, I have the shaft which holds the screw gear - an one piece item that also has the 8TPI thread that drives the main apron. There is some horizontal 'play' in this shaft, in that I can move it laterally about 1mm or so. When it is pushed in towards the headstock, the face of it goes past the face of the 'bush' it is mounted through. Thus when I put the existing 100T gear I have on there, there is metal to metal contact, moving to static, gear to lathe body - this is clearly incorrect and will only lead to wear / friction / heat / /additional strain etc.
On the Stud Gear arrangement, I have 2 keyway washers / bushes, one inboard and one outboard - should I have something similar on the main screwgear shaft such that it is small enough to sit within the static area but large enough to provide a mating face for the screw gear when it is fitted (or spacer bush depending on gear arrangement etc).
Pictures paint etc - you should be able to work out what is what from these: