Working on a Van Norman 1/2 Mill

[Jimustanguitar]

So this is a "1/2" model not a "12" ? They are distinctly different machines?
Mark

Correct, model 1/2 not 12. It's an older, smaller model.

I think your gear is for the worm drive. Looks very similar to my No10 Worm gear for the auto feed of the table. The concave in each tooth is machined. I don't see any logical reason why a straight tooth gear would wear like a worm gear (profile).

Mind snapping a picture of it? I'm curious to see what else is out there.
There's definitely a concavity and a slight angle to it. Maybe it's both a worm gear for the shaft drive, and a helical gear for the handwheel... Although the teeth on Dave's gear in the 4th picture do look awful straight...

 

[benmychree]

That's awesome, thank you! Right now I'm the most curious about the worm drive for the table feed. Does yours spin like I think mine should?

I've also seen pictures of these machines with a 4th handwheel. One of the old scanned documents I found call this a "quick return". What is it?
View attachment 256132
Is that how your motor is configured?

A quick return is a geared up handwheel on one end of the table so that the table can be moved quickly, compared to the direct drive handwheel on the other end of the table. My Brown & Sharpe #2 has that feature.

 

[Jimustanguitar]

A quick return is a geared up handwheel on one end of the table so that the table can be moved quickly, compared to the direct drive handwheel on the other end of the table. My Brown & Sharpe #2 has that feature.

Is it geared to move the screw-nut faster, or is it just a pinion that treats the leadscrew like a rack and pulls it directly?

 

[Jimustanguitar]

Seth from YouTube sent me a picture that sheds some light on my table feed. Looks like there are two gears.

 

[benmychree]

Is it geared to move the screw-nut faster, or is it just a pinion that treats the leadscrew like a rack and pulls it directly?

It just turns the screw faster; on my B&S, the handwheel has an internal gear in it's backside that meshes with a much smaller pinion gear on the screw; I'd guess that it is perhaps about a 5:1 speedup ratio.