Van Norman Duplex No.2 with 50 taper upgrade?

Hello all,

I found myself a VN Duplex No.2 and it appears to have an upgrade on the cutting head. At first I thought it may be a high speed upgrade until I noticed that not many early VN came with a 50 Taper. By my research its a NMTB 50 taper, pretty cool.
It was also suggested in a different place on this board that it may be a roller bearing upgrade. Has anyone seen something similar to this?

WojMo said:

Hello all,

I found myself a VN Duplex No.2 and it appears to have an upgrade on the cutting head. At first I thought it may be a high speed upgrade until I noticed that not many early VN came with a 50 Taper. By my research its a NMTB 50 taper, pretty cool.
It was also suggested in a different place on this board that it may be a roller bearing upgrade. Has anyone seen something similar to this?

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I wasn't even aware that model existed, and I've been paying very close attention to Van Norman milling machines for over a decade. You have a very cool old machine, perhaps the only one of it's kind left, and it would be a real shame to do a lot of "upgrading" of it. You can get good service out of plain bearings, especially if you don't need to run it in production three shifts a day.

According to this link: The NMTBA was founded in 1911. It's not clear when the first NMTBA 50 taper standard might have been proposed. It was apparently patented in 1931 and adopted as a standard in 1938.
See also: http://www.practicalmachinist.com/vb/greatest-hits-and-links/milling-machine-standard-tapers-110670/

Here's an ad from 1913 that indicates that Van Norman made three versions of the Duplex miller, the No. 1/2, the No. 2 and the No. 3. A few No. 1/2 millers have turned up over the years, but this is the first No. 2 Duplex that I recall seeing.

This search will turn up other Van Norman Duplex Miller ads prior to 1930:But I haven't found anything that mentions the spindle taper. It's possible that you have a spindle that has a early version of the 50 taper and is original to the machine.

I would love to see more photos of your machine, especially a photo of the door on the side of the column and any patent numbers that you find elsewhere.

What part of Montana are you from? (I grew up in Bozeman and went to MSU.)

Cal

Here is another thread about another #2 on Craig's List right now.

Given that this mill is one of the early #2, with cone pulleys and no gearbox, I'd say that it was likely built before 1920s. I tend to exclude that the spindle modification is something done at the factory.
It could be working fine, but it is definitely a shop modification (perhaps, done after the original bearings were shot).

We have a #2 at Tuckahoe. Ours has a B&S 13 spindle. Although it's rather beefy, I don't think there is enough room for a NMTB 50 taper. If I remember, I'll check Saturday.

Paolo

Comparing the cutter-heads of the two machines, it looks like OP's machine might have 50-taper adapter in the spindle, rather than a modified spindle. It would be nice to have a peak under the black oil splash shields on OP's machine.

Cal

I also went to MSU (only for my first year) I am in Harlowton - 3rd generation mechanic in this small town. I'm also trying to find out how long these old machines have been in town.

I am currently making a deal for this machine and a couple others. So more pictures is going to take a few days.

I'm not sure of the oil splash shields you speak of. The knurled sections on top and bottom of the spindle are solid metal - no parting lines. In the first pic a mounting bolt can be seen at lower spindle.
The machine definitely has a 50 taper upgrade, the suggestion of a roller bearing upgrade seems possible due to the mass of the knurled sections.

OK, you're north of Big Timber. I've never been up that way.

I see what you're saying now. The black piece on the bottom has been added to the front of the spindle. It looks like the rear was machined down when the black piece in the rear was added. I guess if you're going to go to the effort of putting a 50-taper spindle on the machine, you might as well add taper or roller bearings. Whether or not this was a factor upgrade or something done in the field is anyone's guess. It's possible that the spindle from another machine was adapted to your machine. Have you found any other instances of a No. 2 Duplex with a 50-taper spindle?


It will be interesting to see how that was done.

Cal

Sadly, my memory isn't what it used to be. It turns out I HAVE seen No. 2 Duplex milling machines online before.

Here's a link to one with a fair number of photos: link

That machine had a "C" taper spindle (aka Hardinge 5V). Here's some photos of the cutter-head and spindle:




Cal