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Pratt & Whitney 12C Restoration Pictures

tailstock4

Aluminum
Joined
Mar 3, 2013
Location
Oklahoma, USA
I’m posting some pictures of my restoration of a Pratt & Whitney 12C. It is not a rebuild as that proved to be unnecessary. I bought this machine in Chicago in March 2013. I had to load it in a narrow alley way using a forklift that wouldn't lift high enough. I started my 700-mile journey home in the late afternoon as the snow began to fall. Sound familiar? I've always been willing to trade miles for better condition.

The serial number is 23809 which I believe is either a 1953 or 1954. (Perhaps johnoder can narrow it down.) The 12C has a 14 1/2" lathe swing, 30” between centers, D1-6 spindle nose, 2-speed motor, and a 1000 RPM gear box with 36 speeds from 7 to 1000 RPM. The restoration took about nine months. What follows are the pictures of the restoration of this machine. I plan to post several pictures at a time and explain what they’re about. Feel free to comment, make suggestions or whatever.
 

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tailstock4

Aluminum
Joined
Mar 3, 2013
Location
Oklahoma, USA
A picture of the crane scale as the lathe was being lifted off the trailer.

(If anyone knows how to post these pictures rotated correctly, let me know.)

112.jpg 113.jpg
 
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binzer

Plastic
Joined
Apr 25, 2022
A picture of the crane scale as the lathe was being lifted off the trailer.

(If anyone knows how to post these pictures rotated correctly, let me know.)

Nice looking machine! Nice addition to what looks like a very well set up shop! Great pictures, keep them coming!
 

texasgeartrain

Titanium
Joined
Feb 23, 2016
Location
Houston, TX
I'm so glad to see this thread. Such a nice machine, and P & W make really nice machines.

If you don't mind, I'd like to know what of specs, as far as spindle speeds, actual swing, between centers etc.

I'd also be curious your impressions using it. You have quite a selection of lathes, where does it fit in with what you like to do ?
 

Peroni

Cast Iron
Joined
May 18, 2007
Location
Yadkinville, NC
So that's where this particular machine ended up! I tried to buy it but was a day late. Hit me up if you ever wish to move it along.
 

m-lud

Stainless
Joined
Sep 4, 2016
Location
Missouri
Thanks John

Reg Equip scan (2).jpgYou find the finest of the big heavy beasts. That reminds me of some of the old Monarchs.
Your shop is a fine quality machinery, functional museum.

Earlier I made a post warning of lifting under the pan. I deleted it because after studying it the bulk of lifting is on the base through the motor box. The straps should slip past on the tray when the weight is fully loaded. Some stress there but not much load. I have seen pacemaker trays broke. That may be from fork truck lifting putting full weight on the tray.

That lathe looks well preserved and ready for your rehab treatment.
 

tailstock4

Aluminum
Joined
Mar 3, 2013
Location
Oklahoma, USA
I'm so glad to see this thread. Such a nice machine, and P & W make really nice machines.

If you don't mind, I'd like to know what of specs, as far as spindle speeds, actual swing, between centers etc.

I'd also be curious your impressions using it. You have quite a selection of lathes, where does it fit in with what you like to do ?

I started my post with some of the specs for my particular machine. Others have published the specs in general. If you have in mind anything in particular, I will get it for you. As far as how it compares to my other machines in terms of sheer quality of the fit and finish, it is one of the best machine tools I’ve ever worked on. Pratt & Whitney was amazing. One example I noted was this machine has no gaskets. Every bearing and gear box cover were scraped and shellacked instead. I don’t know if they were all made that way, but this one is. I think it speaks to the amount of skill you have on hand to be able to do that.

I thought I would mention a few additional particulars on this machine as it dictated the way I went on the restoration. I did do a bed survey on the machine once the saddle and tailstock were removed using indicator and a Starrett precision level. It ended up having less than a .001 wear on the front ways and less than .0005 on the back flat. It produced a test bar on a leveled bed of 2” aluminum 8-9” long cut at maximum speed and minimum feed at .001 depth of cut around .00020 to .00025 end-to-end. This is pretty good for a 60+ year old lathe and was acceptable to me.

The spindle bearings and headstock were in good condition producing a run out in the sub .0001 range with very little deflection on the axel or radial, so it was unnecessary to disassemble these.

There were other issues, as there always are with old lathes, and I will get to those.

One thing I would say is that I’m a little uncomfortable about ranking these machines. I don’t feel qualified for that. Besides, I think it depends on what you want to do with them as they all have different strengths and very few weaknesses. They’re all of the highest order and I would be lucky to have anyone of them let alone all of them.
 

tailstock4

Aluminum
Joined
Mar 3, 2013
Location
Oklahoma, USA
These are pictures of the apron and feedbox covers removed. In the third picture, there is a piston pump that is actuated by a fork on the end of the clutch rod. This fork had one tine broken off and had to be brazed back on. However, I didn’t find any oil blockage. Just a very dirty pump felt.
 

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tailstock4

Aluminum
Joined
Mar 3, 2013
Location
Oklahoma, USA
These pictures include ones of the top and back of the apron.
 

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tailstock4

Aluminum
Joined
Mar 3, 2013
Location
Oklahoma, USA
Here are a couple of the top of the feed box under the cast tray cover.
 

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johnoder

Diamond
Joined
Jul 16, 2004
Location
Houston, TX USA
I enclosed a picture of an electrical blueprint that was tucked away in the machine. The date on the blueprint is September 17, 1954. Is this just the date of the blueprint or the actual date of the machine?


23809 is but seven serials (23816) from the end of 1954 - hopefully they were making more lathes than seven 12" since September:D

I like to think of it as some Christmas cheer for a well deserved shop. I was a few weeks from being 15
 

texasgeartrain

Titanium
Joined
Feb 23, 2016
Location
Houston, TX
I enclosed a picture of an electrical blueprint that was tucked away in the machine. The date on the blueprint is September 17, 1954. Is this just the date of the blueprint or the actual date of the machine?

I didn't know the answer to your question, and it looks like John Oder has come though again :D. I was thinking the date looks hand stamped. That would make me think it was related to the specific machine, not just a copied print. When a copy of a print, seems the date is copied also.

Funny enough, I have run into similar things, and thoughts lately. Really taking the time and effort we put into machines, just as you have demonstrated in your shop, we are piecing together not just a highly engineered machines. But piecing together the history. Finding the clues can be fun and interesting in itself.

One example, I picked up a Gorton grinder a couple months back. I was guessing it was from mid 1940's to mid 1950's. Opening the motor start control I found the print dated 1943. Still not sure that makes the machine from '43, but I think mid 1940's is a good guess. For those interested the thread in progress is here:
Gorton 375-2 Tool Cutter Grinder

54.jpg

I love finding little treasures like that. Even simple items. I picked up a thread mic. The advert only showed the mic and the box. Upon receiving it, I lifted the insulation finding an assortment of items including a wallet calendar from 1957:

114.jpg 115.jpg 116.jpg

Love those apron pics. Interesting design with basically two worm gears and two worm wheels.

I rotated the pics in post #3. The only way I found to do it, is to load pics to the pc, which usually shows actual orientation. Then rotate in pc's folder prior to posting. If you have complications, I'll rotate when I see it.
 

tailstock4

Aluminum
Joined
Mar 3, 2013
Location
Oklahoma, USA
... Earlier I made a post warning of lifting under the pan. I deleted it because after studying it the bulk of lifting is on the base through the motor box. The straps should slip past on the tray when the weight is fully loaded. Some stress there but not much load. I have seen pacemaker trays broke. That may be from fork truck lifting putting full weight on the tray.

That lathe looks well preserved and ready for your rehab treatment.

The lifting method that I used was one I got from the Pratt & Whitney manual. It is how they recommend lifting it. The tray the chokers go around is actually pretty heavy. Any way I encountered no problems.

As for the Pacemaker, I lifted it from the bed. I choked around the entire bed at the headstock and blocked on each side of the ways to have clearance for the lead screw and feed rod. Then I choked one other point on the bed and used a come-along to control level. It is possible to lift the Pacemaker with just a forklift under the bed as the bottom of the bed is flat and the forks will clear the clutch shaft.
 

binzer

Plastic
Joined
Apr 25, 2022
These are pictures of the apron and feedbox covers removed. In the third picture, there is a piston pump that is actuated by a fork on the end of the clutch rod. This fork had one tine broken off and had to be brazed back on. However, I didn’t find any oil blockage. Just a very dirty pump felt.

Please keep the pictures coming. It is great to see the similarities to my 16, I will start posting pictures as well as I start keep cleaning and changing oils.
 

m-lud

Stainless
Joined
Sep 4, 2016
Location
Missouri
That lathe is remarkable! It must have spent a good portion of its life on standby for occasional machinery repairs. It never seen production work.
I worked for a printing company that had a monarch that was in that condition. Seldom used but there when needed.
Do you know anything about the lathe's history?

I need to refresh my memory on Pratt and Whitney history. Tony's website
 

johnoder

Diamond
Joined
Jul 16, 2004
Location
Houston, TX USA
Have the November 1943 "C" brochure and letter from PW to Lehmann June 1945 scanned now - about 21 Mb PDF if one of you want to describe how to move it to your device from this desktop:D

I'll use up some posts here and add "photos"

scan01_01.jpgscan01_02.jpgscan01_03.jpgscan01_04.jpgscan01_05.jpg
 

texasgeartrain

Titanium
Joined
Feb 23, 2016
Location
Houston, TX
Have the November 1943 "C" brochure and letter from PW to Lehmann June 1945 scanned now - about 21 Mb PDF if one of you want to describe how to move it to your device from this desktop:D

Emails used to be a 10mb limit, not 100% sure but I think that has increased. I'll PM you my email, if it works I can screen shot the papes.

Other options might be to post to Vintage Machinery, than link it here. Or maybe split the scan in two sections.
 








 
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