Post by jimustanguitar on Jan 29, 2018 21:05:30 GMT -5
I started to upload some pics but the forum seemed cumbersome so here is a selection.
drive.google.com/open?id=11vj9dToVkCbIAywDMflg0hb5qcbJONop
I haven't had the table drive apart, but there is a selector lever (the brass one in the front of the table) that engages the worm which then drives the feed handle and the table. There is a pin to lock the X hand-wheel from spinning, this needs to be engaged or else the screw spins against the feed. I think the feed nut must be within the worm gear so that it behaves like a regular screw feed without power but the power spins the nut allowing it to move the table with the screw locked in position. Try US-patents there are some for Van Norman. I also attached photos of pulling the spindle apart. Feel free to post any of these pictures to the forum if you want. I think if I needed to re-enginner the feed I would rig a stepper motor on the right hand side of the table with a clutch to disable it. I think that would be much easier and cheaper than trying to recreate the original. I would miss the feed hand wheel on my mill though as it does provide a nice rapid traverse, it is too bad they removed it when the redid the drive on your machine.
I hadn't thought of looking up the patents yet, that's a great idea! I should also probably dig into the Waltham Watch Company's documents, because that's who originally manufactured this model.
I agree 100% with your tip on not recreating the 100 year old wheel. I actually came upon some tube motors that came out of 15' long projection screens that I was going to tear apart and look into the feasibility of rigging up for a power feed. Those are AC motors with adjustable stop points, so they wouldn't be as nice as programming steppers, but they'd certainly have the torque for the job. I bet I could raise and lower the knee with one of them...
Anyway though, thanks again for your pictures and description! I'll keep the thread up to date with my progress.