Can anyone ID this Pratt and Whitney? It's my new project! And I know NOTHING!

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Hi Everyone!
I know almost NOTHING about metal working other than rare lathe work, but I'm here to learn!!!
I found this bench top mill (at least that's what I think it is!) on CL, and purchased it today. No model number anywhere. It has a number "163" visible in the ways. Might just be a serial number...
Every Pratt and Whitney mill I've been able to find online is a "3" or "3C". I think this pre-dates them, as this doesn't have any provision for an overarm (obviously you can ignore the aluminum add-on)... And most interestingly, the rotating assembly can be positioned forward and back about 3 inches in the Y axis. The 3 and 3Cs seem to have fixed/immobile tops.
It was originally built for an overhead belt. The motor and belt configuration is a later add-on. The cabinet is an incredibly solid wooden one. Inch thick plywood, molded corner boards, even built-in wheels - you name it. So well made it looks like sheet metal.
Questions:
1) Anyone have an idea what this is?
2) It came with a single Bridgeport B3 collet and associated draw bar. There's another draw bar with it, slightly longer. I've looked, and these B3s seem to be rare... I don't know much about collets -do I have options - even if I sacrifice accuracy - if I can use other kinds?
Sorry this pictures are sideways... That gives me a headache!

I'm sure I'll have more questions. Can't wait to start exploring this! THANKS!
- Paul

What you have is a machine tool which started as a "stub" milling machine. These were very small/light duty horizontal milling machines built without provisions for an overarm and milling arbor. They were designed to run small cutters such as end mills, Woodruff keyseat cutters, and similar which could be mounted in an end mill holder or collet. This type of milling machine was often used in the production machining of small parts rather than as a true manual milling machine. It was typically outfitted with a setup or fixture, stops were set, and one machining operation was carried out repetitively. Parts for small mechanisms such as firearms, sewing machines, typewriters (remember those ?), clocks, pressure gauges, small electric motors and appliances...

Someone got the idea to convert this little production stub milling machine into a true horizontal milling machine by adding clamping plates to the mainframe of the machine to take a round overarm. This is all well and good, but if the spindle of the machine is made to take a small sized collet, getting a milling arbor to fit that spindle may require machining one from bar stock. Assuming an arbor did exist, the capacity of horizontal milling cutters would be quite light/small. Something like running slitting saws or very narrow or small diameter milling cutters might be about all the machine could handle.

Sorry to say you have a morphrodite or "frankenmill". In its original condition, the little Pratt & Whitney stub mill was capable of a high degree of accuracy. Having been through a number of hands and having been modified, it is anyone's guess now as to what condition the mill is in. Wear on the dovetail sliding surfaces on the table, saddle and knee as well as condition of the spindle bearings are the factors which determine accuracy. Whether the machine was hard used, whether it was properly maintained and lubricated, these are all unknowns. My guess is someone who worked in a machine shop or something like a college lab's shop got hold of the mill and modified it as a "government job". Government Job is the term oldtimers used for jobs done in their employer's shop for their own personal use. Various reasons for this name, but the likely one is simply that anything being built for the Government was usually "top secret". So, if a machinist brought in the neighbor's kid's bicycle frame to straighten it and braze it back together, or make a new axle for the family baby carriage, these were government jobs. If the guys asked what the machinist was working on, the answer would be: "It's a government job...." 'Nuff said. It was "top secret". Getting back to your milling machine, my guess is it was a government job, as the tooling plate used to make the overarm supports and the work needed to bore them would all be a stretch for some guy looking to make a small mill for a home shop. Cutting off "scrap" tooling plate and setting it up and boring it for the overarm, and finding a "scrap" of cold rolled round stock (or turned-ground-polished stock) of the length and diameter for the overarm would put a dent into a man's wallet if he had to buy those materials. Whoever did the conversion must have seen light duty horizontal mills like the "Benchmaster", which was common in lab machine shops in the 50's and 60's. The overarm mounting design looks like it was inspired by a "Benchmaster" mill.

In short, you have a very light duty horizontal mill. The BP collets or whatever collet it does take are going to be of a fairly small capacity. A true horizontal mill arbor would have a diameter of 3/4" or 1" for a light small mill. If you had an arbor with a small diameter in line with the collet capacity of the spindle, the arbor would likely be too springy for much work. If you had a 3/4" or 1" diameter arbor, asking the light spindle to turn it with a horizontal milling cutter becomes a case of the tail wagging the dog, in my opinion.

For small and light work, I am sure the machine will be usable. Something like playing making parts out of aluminum or mild steel with light cuts would be about it.

Hardinge Brothers made similar bench millers from around 1907 until the 1950's, some thousands of them. They were made with 3C (1/2") spindles at first, but most are 4C (3/4"). The table was about 3" x 12" with three T-slots. A wide range of accessories were made, including power feed, vise, indexer, tilting and swiveling bases for the indexer and rack and pinion feed for production work. I made a few hundred production parts on one of mine years ago and it was a perfect machine for that job. I saw one in Chicago that was being used for a tiny surface grinder. Most are horizontal, but they did make vertical versions.

The pictures are from a 1946 brochure and show the ball bearing spindle mills introduced about 1936 and built in Elmira. The previous versions had flat belt drive and plain bearings like the other Hardinge machines built in Chicago.

Larry

Thanks Joe and Larry!
I'm just a beginner, so I'm sure I'll find it useful. I've never used collets in my lathe (and honestly don't know much about them). I suspect specific devices use specific collets - does that mean I only have one option? Or are there some that will fit? This machine has "B3" on the collet) are there equivalents?

And by the way, this thing is HEAVY. I had NO IDEA something so small could weigh what this thing does!!!!!!

- Paul

Paul,

Welcome to the forum. We all started as beginners.

Yes, there are many sizes and types of collets, and most of them are NOT interchangeable !

This machine is old, probably made before WW2 and maybe before WW1. Unless someone re-bored the spindle to a different size, it will use some old-time collet type. How about a picture of the existing collet, with something to show scale? Measure the collet and post the dimensions.

It's a Pratt & Whitney, so if the spindle bore is original, AND it pre-dates the 3C, then it may use 3PN collets.

There are at least two firms, Royal and Hardinge, which make collets to order. Not cheap, but you don't necessarily need a full set. Plus, there's always eBay!

You seem to be correctly focused on identifying the collet type. "B3" is not a likely type for a machine this old. Get us the photos and dimensions, and the forum will do its best to help you out.

John Ruth

And, the spindle may not be at the original taper etc. My FIL has a P&W 1 1/2 very similar to that unit (but it is floor standing), and it has a taper that has been modified at least a couple times, IIRC it is now a Morse, MT2.

It'a been a long time since that unit in the pics was made, and since it is still around, there's a fair chance that it has been updated in ways beyond the overarm stuff.

There's a large doubt in my mind that this is pratt and whitney. There are a number of features that don't fit with
that company in this machine. The dials and handles in particular are very similar to sloan and chace.

There are apparently no maker's logos anywhere on this machine?

Hi all!!
Thanks for all the thoughts!!! I touch a bunch of collet and draw bar pictures. As to whether it’s a Pratt and Whitney, I have to assume so as it has what looks to be the original (painted over) plate. Unless they re-logo’d other vendors hardware.

Whalerman said:

Hi all!!
Thanks for all the thoughts!!! I touch a bunch of collet and draw bar pictures. As to whether it’s a Pratt and Whitney, I have to assume so as it has what looks to be the original (painted over) plate. Unless they re-logo’d other vendors hardware.

Click to expand...

WELL... if it has a makers plate.. for crips sake show us a picture!!!
kinda pertinent to the matter at hand, no?

Of course I couldn't figure out how to load the pictures from the iPhone. So transferred them to the PC... Here goes!View attachment 218990View attachment 218989

Whalerman said:

Of course I couldn't figure out how to load the pictures from the iPhone. So transferred them to the PC... Here goes!View attachment 218990View attachment 218989

Click to expand...

Something goes wrong when I try to open those to a size large enough to actually SEE. "invalid link" message.

Figuring out the picture process SLOWLY :-) Not able to upload pictures easily for some reason...

Whalerman said:

View attachment 218993

Figuring out the picture process SLOWLY :-) Not able to upload pictures easily for some reason...View attachment 218995View attachment 218994

Click to expand...

That's working, but.. there are file size limits to the uploads. No warning message. Just carries-on, then eventually quits.

My photos are not great, but what has worked is to bring the high-res .jpg up on my own screen, mess with the zoom, then take a "screenshot" of part of it and save as a .png

The now-much-smaller file loses resolution, but will at least fit PM and auto-zoom "somewhat" when clicked on.

OK. This stinks, but I've been trying to upload photos and manage attachments for half an hour. So rather than struggle anymore, here are some measurements. Forgive my non-machinist collet terminology. If anyone can tell me other collets that might work, I'm interested. With the mill came a second draw bar of the same diameter, but half and inch longer... I'm wondering if there are other collets that are shorter that would also work in this device. THANKS FOR YOUR ASSISTANCE!

INSERT:

length - 3.112"
OD at narrow end - 0.648"
OD at wide end - 0.791"
ID at narrow (threaded) end - 0.391"

COLLAR:

ID at narrow end - .711"
ID at wide end - .800"
OD at wide end - .990"

DRAWBAR:

OD - .767"
length (internal portion, from inside of "washer", including threads) - 6.5"

One other thing - there’s a chain like a bicycle chain that falls through a hole in the top of the cabinet. It’s attached to a pulley (inside the mill), on the handle/gear that lifts the z axis (the really heavy part!!!). I’m wondering - could that be for a counterweight???

I know a little more now!!! Is there a resource that can ID collets out there?

Thanks everyone for your patience. I've learned a lot over the last week regarding collets and my mill. I took a flashlight out to my garage, and looked into where the collet goes, and WHOA - partially down the channel, there's what looks like a bushing that may have been inserted after the mill was manufactured. I'm only guessing this, but why wouldn't the manufacturer have milled it out to the dimensions originally... This bushing brings the spindle diameter to just big enough to accept my B3 collet.

So here's the question(s) I have - the drawbar is 3/4 inch. The channel it goes into is (OBVIOUSLY) just a bit larger. In FRONT of this bushing, the channel returns to 3/4", and then expands out to almost exactly a 1" diameter. I've looked ALL OVER for a table of collet sizes, but I just come up with a ton of random web entries.

Here's what I think I need to find out: what kind of collet has a .75" tube OD, a 1" face OD, a depth from face to the 3/4 spindle bore of about .615", and an angle of approximately 11.5 - 13.2 degrees on one side, or a total opening angle of 23 - 26.4 degrees? I'm calculating the angle based on crappy measurements, so a range is best I can do... Maybe I can do better with a protractor when I get home...

My thinking is that if there's a standard, easy to purchase collet set that would fit if that bushing we're down there in the spindle, I'd chuck this thing in my lathe and bore it out. Or get rid of it some other way...

ANY THOUGHTS??? THANKS ALL!!!

- Paul

Lots of collets listed in the ancient Hardinge catalog - when they were still in Chicago - none like what you are wanting.

Suggestion - assuming you actually want to use the machine sooner than later

Forget unknown / unobtanium collets - on edit - a reason for this is they can be astoundingly expensive to have made. I still have the Hardinge bill for over $1100 for two measly collets they made for me in 2003

Look into adapting ER series collets to your spindle nose - modern - readily available - in a large range of capacities