Van Norman Model 1/2 "Duplex" Milling Machine

The Van Norman "duplex" machines first attracted my attention when I visited a friend who has a model 12. The head on the Van Norman "duplex" machines rotates about a horizontal axis parallel to the "x" axis, allowing the machine to function either as a vertical or horizontal mill. This feature was patented in 1896 and was the defining characteristic of the Van Norman mills until well after WW2. When a model 1/2 came up nearby, I went to look and immediately decided I had to have one.  Its a nice size for a home shop - large enough to do real work but not so big that its a major rigging job to move. I didn't get that one, but have since become a regular correspondent with the person who bought it.

I found one several months later in Havre de Grace, MD, about an hour away. As a bonus, I learned quite a bit about Havre de Grace history from Mike Tarbert, the seller. The machine is now resting patiently in my "shop".  Ken Cope, author of several books on old machine tools, was kind enough to help bound the date on this machine.  The earliest reference he has to this model is 1911.  My machine still bears the "Waltham Watch Tool Company" label.  That company was reorganized as Van Norman, and moved to Springfield MA, in 1912, so my machine was made in 1911 or 1912.  The serial number is 777.

This machine came rigged with a mechanical variable speed drive (a "Ringroller" by Graham), which is still serviced (and possibly manufactured) by Motor Specialties.  Zero to 1000 rpm output. . 

The Van Norman 1/2 and 12 (and probably some others) take a Van Norman "C" collet, also known as Hardinge "5V".  Still available from Hardinge, but at prices well beyond what most home shop machinists are willing to pay.  Fortunately, I got a set of collets with the machine, a couple of good arbors, about 30 nice end mills with B&S 7 shanks, and a Van Norman to B&S 7 adapter.  I'm not sure when Weldon shanks became popular, but it must have been after the date of manufacture of this machine.

Vertical Mode	Horizontal Mode. Note that the upper frame can be moved in and out to position the head to best advantage.
The handwheels are, from left to right, x-axis, z axis, y axis, and rapid x	A catalog page ca. 1920

A B&S #7 left-hand end mill and the VN "C" to B&S 7 adapter

Good sources of information on the Van Norman machines:

STRANGE WAYS -- The gibs on this machine are a bit different.  For the x-axis, one side of the ways is a heavy bar, one side beveled to form the dovetail.  The bar (gib?) is fixed in position by 4 vertical fillister-head screws with the heads running in tight counterbores.  The table lock is a threaded handle, running up from under the saddle, and threading into the gib.  So, to lock the table, we clamp down on the gib.  This implies that the gib must have some free movement, adjusted by the hold-down screws.  In the picture, you can see the clamping handle for the z-axis, which works the same way.