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Pratt & Whitney 12B Profiler - How does it work?

Citxmech

Aluminum
Joined
Aug 23, 2018
Location
Seattle, WA
Anybody have a link to a video or manual showing the basics of how an old manual profiler actually functions? I was recently looking at an ad for a P&W 12B for sale locally, but from the pictures and a P&W brochure I was able to find, I can't really figure out how it works. Seems like it should have some kind of pantograph mechanism, but the unit I was looking at had none - and didn't even have T-slots for the table.
Thanks!
 
Follows template made for each job. You supply the muscle via the two cranks to move things around in "X and Y" (terms never applied to machine tools then) while keeping tracer stylus hard against template

No feeds
No screws
Often two spindles
Optional side uprights for taller parts
1923 tool catalog by them shows many cutting tools offered for profilers - though does not show the inverted "barrel" cutters for the elegant but understated CURVE on the periphery of such as a trigger guard

Never panto graph equipped that I know of

P&W sold them world wide - up to the 40" size - used to know where to find one captured in an old Mauser factory photo in the fatherland

Manuals available

VM has 1908 catalog - Profilers start on PDF page 25. Check out work done at the end of section - ON EDIT PDF page 32 is showing some SHARPS rifle parts from the 1870s:). Looks like Model 1874 side plate and trigger guard / block dropping lever ( I own a M1874 by Shilo)

http://vintagemachinery.org/pubs/1412/21553.pdf

ph
 
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I used a Morey profiler which was very similar to the PW. Ditched that for a much smaller Thompson sliding table mounted to a vertical mill. Perhaps the sweetest manual set-up would be an old Gorton with wobble table...?
 
Thanks! That's the brochure I found - I just couldn't identify where the stylus is or where a template would be clamped. I'm very intrigued by those parts examples though. I'd love to see one of these things in action.
 
Thanks! That's the brochure I found - I just couldn't identify where the stylus is or where a template would be clamped. I'm very intrigued by those parts examples though. I'd love to see one of these things in action.


Here is a little scan from back of manual. The .833 diameters are the stylus. Template bolts to table. Stylus comes down with head

PW Profiler Diagram.jpg
 
Oh, there we go! I missed that diagram. Makes way more sense now. Thanks!

So, with the dual spindle machines, do you advance your parts from a fixture on the "roughing" side, to a fixture on the "finishing side" kind of like a manual multi-stage die press?
 
Oh, there we go! I missed that diagram. Makes way more sense now. Thanks!

So, with the dual spindle machines, do you advance your parts from a fixture on the "roughing" side, to a fixture on the "finishing side" kind of like a manual multi-stage die press?


I imagine that there was lots of that sort of thing going on - you might have several set ups just to get all the way around a part , and of course in a production environment you may have 20 of these machines in action
 
Understood.
Thanks for the insights! I've always wondered how items like those beautifully sculpted revolver hammers were actually cranked out in a production environment.
 
I was thinking about the double-spindle units. Since they both have their own tracing stylus, you really wouldn't need to re-fixture a part to do two cuts if you could set the tool/stylus clearance for each cutter (which I'm sure you must be able to do somehow).

The more I think about this thing, the more I want one.
 
Citxmech:

Your statement about the lack of "T" slots on the table of the P&W 12B Vertical Miller and Profiler has me a bit confused. Both the
Single Spindle and the Double Spindle machines use the same size table with a working surface of 14 inches by 18 inches. Both tables
have three "T" slots for 5/8 inch bolts. With the Double Spindle machine you can do a roughing cut on one spindle and a finish cut on
the other spindle or two roughing cuts or two finishing cuts. The master patterns can be cut from plastic or aluminum depending on the
number of parts. Because the tracer is held against the pattern and simply follows the outline of the pattern, duplicating parts is a very simple matter once you get the feel of the handles. The milling cutter and the stylus diameter are usually the same, which makes tracing very easy. Unlike a pantograph, an increase or decrease in size is not possible since the master determines the size of the finished product. The Spindles are bored for a B&S No.9 Taper, so a good selection of B&S No.9 End Mill Holders is helpful. The depth
of the cut is controlled by locking the spindle in position. A very handy machine for a variety of "one off" jobs.

Hendeyman
 
Thanks for the additional information! The picture of the machine I was looking at was obscured by crap sitting on the table - and if you look at the brochure, they don't seem to indicate table slots. Probably just an artistic oversight.
 
And there were "regular" and OVERSIZE tables. :D

My notes from well over 20 years ago (Feb of '96) say my over size table had no tee lots and on top that was bolted an aluminum block that they had cut tee slots in (We suppose it was okay to tap holes at random in this table)

Parts book says over size table was 19 1/2 X 32" . Regular table had a 14 X 18 working surface with large oil troughs

Weight on these is amazing for such a little bit of machinery - 4400 for two spindle
 
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The milling cutter and the stylus diameter are usually the same, which makes tracing very easy. Unlike a pantograph, an increase or decrease in size is not possible since the master determines the size of the finished product. The Spindles are bored for a B&S No.9 Taper, so a good selection of B&S No.9 End Mill Holders is helpful.

By changing stylus size and cutter size can you increase or decrease the size of the part in relation to the pattern? No as much as a pantograph but maybe + or - 15% or so?
 
You're rather changing the shape of the part, not much the size. And, in certain cases, you would obliterate the part by using a cutter larger than the stylus: think about a trigger guard, where you need to cut both the inside and outside profiles. If the diameter of the cutter is larger than the diameter of the stylus, the inside and outside cuts would meet without leaving any material in between.

Paolo
 
So, I've been thinking about this a bit more (I know, there I go, working without tools again). On the double-spindle machines in order to adjust the depth cut between a roughing and finishing cutter, unless you can adjust the distance between the stylus and cutter center line, it seems you'd need to custom-turn the stylus itself: i.e., measure the cutter radius and set your rough cutter stylus radius bigger than the rough cutter by the depth of your finish cut and then set the finish stylus at the exact diameter of the finish cutter. Does that sound correct?
 
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Looks like I'm going to be picking up that 12b I was looking at. Anybody have a good source for an operators and/or parts manual? s/n is No. 688, not sure of the year, but it has an electric motor from the factory so I'm assuming it's 40s or later.
 








 
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