Pratt and Whitney 3C Lathe and Mill

[smmagic]

I would like to start by saying that this is my first post but I have gained a lot of information over the few years that I have been a member. A little about myself, I have been metal working for a little over 6 years now, mainly working with micro machining of model engines or mechanical watches. I graduated from high school this year and will be studying mechanical engineering in college in the fall.

As for the lathe and mill. About a year ago, I purchased a Pratt and Whitney 3C lathe (7x16). It came with two chucks, one mounted to the original faceplate and the compound, tool rest, as well as a full set of collets from .050 to .375 by 1/64ths, along with 1/2, 5/8, and 3/4. Unfortunately, I am missing one collet out of this set, the quarter inch collet.

A few months ago, I was fortunate enough to find the companion mill; however, it was in need of much restoration. The only things that were included with the mill, were the original vertical head, a matched set of two original Pratt and Whitney vises, half of the original speed ranger, some odds and ends milling components, and only one horizontal milling arbor. Also there were three parts off of the mill that were completely missing – the clamps for the vertical head, the knee gibb, and the plate that covers the pulleys for the spindle. I am currently in the middle of the restoration for the mill and will post finished pictures of it as soon as I am finished.

The pictures below are the lathe in its current state and the mill and associated parts as I purchased them prior to restoration.

Does anyone happen to have a 1/4in 4PN collet, any Pratt and Whitney milling arbors, or any other Pratt and Whitney components that they would be willing to part with? Also any suggestions as to how to approach the missing gibb or other missing parts would be greatly appreciated.

Thanks in advance

 

[rivett608]

That is a really nice set up, all ready you have more tooling than a lot of guys will ever get. I used to have a pair of these when I lived in MD.

Be careful taking apart the vertical head, there is some sort of ring part in there that is very fragile and often cracked. Also the bearings for these were really expensive.

Good luck finding more stuff.

 

[moonlight machine]

Hardinge will probably be able make you a collet. They do make lots of oddball collets.

 

[alskdjfhg]

Hi SM, I graduated HS this year as well and will be studying mechanical engineeing too.

That looks like a really nice machine, wish I could be of some help to you on it.

 

[Iridium77]

I have a Pratt and Whitney gearbox countershsft that I will use on my Rivett No.5.

The gib you will have to make. The collet would cost a lot to get from hardinge. My Rivett No.5 takes 5OS collets and hardinge doesn't have them in their range of collets they make. I would make a collet and harden it, that's one way.

I do know a person who has a 3c mill, with all or most of the accessories and are in excellent condition. He would only sell everything and his price is high, and I do not know if he is still willing to part with it.

 

[gwilson]

I restored one of those lathes for a behind the scenes blacksmith shop in the Williamsburg museum back in the mid 80's. They made items for sale,and only needed the lathe to make non threaded parts. I even found an extra motor drive for them in a Pennsylvania flea market.

I think that lathe is now at the Golden Horse Shoe golf shop,which is part of the museum,in the maintenance shop where they repair golf carts.

There were no collets with it. They just used a 3 and 4 jaw chuck.

 

[Andy FitzGibbon]

I have the 3C mill/lathe combo that all mounts to one 10 foot long bench. It's in need of a lot of restoration, which I hope to get to soon. I also have a mill, by itself on it's own bench. I have a lot of collets, and may have a spare 1/4". I'll send you a PM.

Andy

 

[rbdjr59]

Really nice bench for that lathe.

 

[Herb in Delco]

Contact the guys at the Tuckahoe Museum. Great bunch, and could be a lot of help with that mill. Great setup, by the way.

Herb

 

[Don Nielson]

When you get the mill restored I have a complete dividing head kit with gears and collets that is made for it. D

 

[smmagic]

Thank you to everyone who provided any information.

Here is a quick update on the mill restoration.

As of right now, I have the mill disassembled, all of the rust off, and all of the old paint stripped. I am hoping to have the mill primed and painted within the next week or so.

In addition, I have one of the vises almost fully restored but have yet to start the other. Once I have one finished I will post a comparison picture. Also, I have posted a few pictures of the vertical head, in its current state. I started disassembling it because it felt a little tight, and the entire inside turned out to have rust.

As for making the gibb for the knee, would that need to be ground cast iron, or can it just be machined out of cast iron, or steel?
Any help or tips for further disassembling or restoring the vertical head would also be greatly appreciated.

Thanks again

smmagic

 

[morsetaper2]

smmagic,

If you do a google search for "Pratt & Whitney 3C" you will uncover a lot of information in many threads in this forum. I also have a 3C mill. Have some pictures in an album found in my profile.

Where in MD are you located? What college you going to?

 

[jim rozen]

Your lathe is the more modern version, and has a very nice compound slide. Mine is the older version, open belt:

Your milling machine and its associated parts looks a bit rough but not much rougher than mine when I got it. The
tooling with it is very nice. Mine cleaned up nice:

I did dismantle and clean up a vertical head and took photos of the process. I can send them to you if you want.
Drop me a line at jrr(zero) at us dot ibm dot com with your e-mail and send you the files.

The vertical head they made is quite amazing. It's not clear to me at all how P&W made any money at all making those
as the parts are incredibly precise and well machined. The spiral bevel gears in those are individually marked for fit
and manufactured to an amazing level of quality.

Jim

 

[Iridium77]

The gib would have to be hand scraped. For the material I would ask Richard king what to use.

 

[Marty Feldman]

3C

As you will probably already know, a number of the guys on this site have had 3C's. They include rivett608, who did this a long while ago:



Two other notes. I didn't see a mention of Tony's archive. If you haven't already been there, it's lathes.co.uk. The other thing, on that .250 collet you're looking for. In addition to having Jim Rozen's machine restorations as a standard to shoot for, he has come up with some collet mods that should work for you in case you can't find something in 4PN.

You have a great project going. Please bring us up to date before school starts in the fall.

-Marty-

 

[jim rozen]

Unfortunately my trick on the collets in the lathe (using modified 3C collets) won't work on his lathe
or milling machine, as those both take larger collets. His lathe is the more modern underneath drive
one, and has a large diameter spindle (and ball bearings as well!)

I've got to bring the vertical head files in to work so I can send them off to you. If I can
staple a note to my forehead tonight as a reminder, this can happen in the morning!

 

[SteveM]

I wondered what happened to that mill. It was on ebay and then the seller pulled it because of "an error in the listing".

I have some spares. Sending you a pm.

Hardinge will probably be able make you a collet. They do make lots of oddball collets.

Last number I saw was $395 each. That would be about $18,000 for a complete set by 64ths and about $30,000 if you included the decimal and metric collets that were available.

Hey, Jim - keep forgetting to ask you: how did you get the unpainted surfaces on that mill so clean? They almost look new.

Steve

 

[smmagic]

Hey everyone, sorry it has been a while since I have posted anything on here regarding the mill, but here is a major update.

So far I have had everything except the spindle housing disassembled, cleaned, and all but a few parts primed and have had 4 coats of paint. As for the color, I decided to paint it a true blue, mainly because I really liked the color, and the only other color that I was really considering was the same color that my uncle used to restore his antique milling machine (an old Vernon). In addition, I have cleaned almost all of the accessories that came with the mill except the overhead, which I am taking my time with, and the tailstock that would have gone with the dividing head. In addition, I would like to thank Andy for helping me out with the original pulley cover, the quarter inch collet, along with sending me a knee gib that can be used as a template of sorts for making the new knee gib. As for the gib, all of the parts have been ordered and will hopefully be in sometime tomorrow and with any luck, the gib will be done by the end of the week next week. However, I am at the stage as to once the gib is finished, the mill can be reassembled and hopefully functional as a horizontal mill, until I finish the restoration on the universal head. Hope you enjoy the pictures below!

 

[jim rozen]

If you'd like to recoup some of your investment, sell me one of those vises!

=)

Jim

 

[smmagic]

Hey everyone,
The progress on the mill is currently at a standstill until the knee gets machined which won’t be until sometime next week; however, this has given me some time to start on the vertical head, as well as restoring an original Pratt and Whitney bench that I picked up over the weekend (I will post some pictures of the bench tomorrow). Just as a side note, I will have to give a shout out to my dad because he is doing most of the wood work on the bench, mainly because he loves woodworking and hates working with metal, and I am just the opposite.

I haven’t posted much about my lathe, as I purchased it in running condition, and really didn’t need to do much with it to start using it; however, I picked up an interesting original Pratt and Whitney attachment for the lathe. On eBay, I found what I had thought was a set of gears for the dividing head. Upon discussing the item with another Pratt and Whitney owner, I determined that these were all of the gears for the original threading attachment for the lathe. Unfortunately, it did not have the cover or yolk that the gears attach to the lathe with, so I think once I get the mill up and running, I may try to recreate the rest of the parts for this attachment.

Also just something that I noticed on a lot of the original Pratt and Whitney stuff, is a small “5C” or “5H” punch. Is there any meaning behind these markings?

Thanks again