There were two "generations" of Model 16 mill. The original #16 was made from 1947 through 1955. Serial numbers indicate that 565 of them were made. The original #16 seems to be a transition machine, between the #12 and the larger machines. It is a little bigger than the #12, but not a lot. It has power feed for the table only, like the #12, but the feed motor is inside the knee as on the larger machines (which have power feed in all three directions).

The second generation of the Model 16 was made between 1955 and 1960. There were three variations: the 16L, 16M, and 16S. I don't have much detail about the L and the M, and I'm afraid the specs in the model number table probably mostly based on the original #16, but may contain a mix of the L, M, and S specs as well. However, I recently ran across a 16S at a surplus dealer, and I took some photos. Click on the small photos to get a larger version:

Unlike many of the older machines which had a fixed belt ratio and did all speed changes with gears, the 16S uses a combination of a four-speed step pulley and a two-speed gearbox to provide 8 speeds from 110 RPM to 3600 RPM:

The belt is loosened and tightened by sliding the motor. There is a lever on the right side of the machine behind the belt guard, which rotates a pinion that in turn drives a rack on the bottom of the motor slide. A pin locks the lever in the 'belt-tight' position. The previous owner of this machine must have used it almost entirely for vertical work, so they turned the overarm around with the support bracket hanging off the back. At least they didn't scrap the bracket, which so many machine owners seem to have done.

As mentioned earlier, the feed motor and feed gearbox are in the knee:

The 16S is one of the few Van Norman models to have a quill. The one I saw had a 30 taper spindle - I don't know if all 16S mills have the same taper or not.

The quill head has power feeds in both directions, driven by a pick-off from the spindle. The feed can be set to 0.0005, 0.003, or 0.006 inches per revolution, and can feed in either direction. The power feed can also be set in 'neutral' and a small round knob on the front of the head can be used to make fine quill adjustments, or the entire power feed mechanism can be disengaged and a larger quill handle can be used for drilling. I believe the widget in the last pic is either a depth indicator or a stop that disengages the power feed at a certain depth, but I wasn't able to figure out which.

Thanks for visiting.