Missing a bit from the leadscrew?

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mynewviceroy
Posts: 22
Joined: Tue 11 Apr , 2023 13:15 pm
Hardware/Software: Denford Viceroy TDS 1 S
Location: Nr Newent, Gloucestershire

Missing a bit from the leadscrew?

Post by mynewviceroy » 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:
Attachments
IMG_20230415_103047a.jpg
Stud Gear shaft with rotating aspect proud of the lathe body.
IMG_20230415_103047a.jpg (20.28 KiB) Viewed 17128 times
IMG_20230415_103622a.jpg
Screw gear shaft with bush fitted. Bush touches and rotates against lathe body
IMG_20230415_103622a.jpg (20.43 KiB) Viewed 17128 times
IMG_20230415_103101a.jpg
Screw gear shaft pushed towards the lathe body
IMG_20230415_103101a.jpg (19.59 KiB) Viewed 17128 times
IMG_20230415_103012a.jpg
Screw gear shaft pushed towards the lathe body
IMG_20230415_103012a.jpg (18.63 KiB) Viewed 17128 times
IMG_20230415_103656a.jpg
Close up showing where screw shaft bush has worn against lathe body
IMG_20230415_103656a.jpg (15.7 KiB) Viewed 17128 times

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