Another neck turning thread.

Al,

Great information to have. I'm trying to soak up all I can, so I'm going to go through and re-read this a little later today.

If anyone knows where a guy could find a tailstock for a Model C Pratt & Whitney lathe (16x30 if it matters), I'd be eternally grateful. Going to look at one right now that appears to be in phenomenal condition, M1696 Serial 557.

Thanks,

Jim
 
On lapping bells..... in looking at Jerry's pix, I may have misspoke. The rod he's measuring off of may well be setting in a finished crown....but in ANY case, using this method you've got to start somewhere, and you will either be stuffing a rod into a lapping bell or a bandsawed-off barrel or you're gonna' be flipping it end-to-end a few times whilst you work your way in to something decent....

Which is why I use long stem test indicators on both ends when I rough in a setup like Jerry is using to chamber. And yes, I've found runout in the first 2.5 inches of both ends.
 
Okay, so it looks like I've acquired a lathe.

It's a 1957 Pratt & Whitney 16 x 30 Model C. The ways are in overall excellent condition, it has a 3 jaw chuck that's original to the lathe, and from appearances it's been used very lightly in a small shop. The carriage assembly is all solid, though I think that the gears on the course traverse wheel may be a little rough, the leadscrew is clean and undamaged. The spindle is solid, and all the levers operate smoothly with no grit or chunk. The lathe has been in storage for years, and was not under power. One thing that I am going to have to track down is a tailstock for it, the previous owner did not use one and the lathe is missing the original. Any ideas where I can track one down?

Oh yeah, I traded an AR15 for it.

I inspected the lathe to the best of my ability (don't have a dial indicator or I would have checked runout at the spindle bore on both ends), and it appears to be a great machine, the catch is the missing tailstock. If anyone knows of a good machinery mover in the Houston area, I'd be buying them a drink.

Jim
 
The chamber end is dialed in with an Interapid indicator and a probe that extends into the chamber neck area. Then I predrill slightly smaller than the chamber shoulder and bore to about 0..010" undersize for the reamer body to follow. This allows the reamer pilot to engage the indicated area just as the reamer body engages the prebore. That way all the curvature of the breech end, if any, is gone.

15o8rb7.jpg
 
JerrySharrett said:
The chamber end is dialed in with an Interapid indicator and a probe that extends into the chamber neck area. Then I predrill slightly smaller than the chamber shoulder and bore to about 0..010" undersize for the reamer body to follow. This allows the reamer pilot to engage the indicated area just as the reamer body engages the prebore. That way all the curvature of the breech end, if any, is gone.

15o8rb7.jpg
Click to expand...

Nice.... the "2 points" then are muzzle a the throat, good choices IMO. And on a PPC it should hit within a couple inches a 100.

Now try do a 30-06 :)

Or a 32" long 338 Lapua!
 
I realized I needed to fix my bad terminology...

The carriage handwheel is a little clunky for about 180 degrees of rotation, then smooth, for every rotation of the handwheel. Is this going to cause me problems?
 
Jim Cox said:
Okay, so it looks like I've acquired a lathe.

It's a 1957 Pratt & Whitney 16 x 30 Model C.

. One thing that I am going to have to track down is a tailstock for it, the previous owner did not use one and the lathe is missing the original. Any ideas where I can track one down?

Oh yeah, I traded an AR15 for it.

I inspected the lathe to the best of my ability (don't have a dial indicator or I would have checked runout at the spindle bore on both ends), and it appears to be a great machine, the catch is the missing tailstock. If anyone knows of a good machinery mover in the Houston area, I'd be buying them a drink.

Jim
Click to expand...
Traded an AR 15 for it. Good trade. Those little POD (Piece of Dooky) guns was where the PTA (Powers That Are) started disarming the American GI's.

Tailstock? Rots of Ruck!! Try a Yahoo search for "used machine tool parts"

That sucker will be heavy.
 
JerrySharrett said:
A 32" long 338 Lapua?? Wonder were they got the brass?
Click to expand...

Probably necked down a driveshaft from a Freightliner!


It's definitely heavy, I'm trying to figure out how I'm going to move it without paying the movers more than I got the lathe for! I'm looking around trying to find a tailstock for it now, hopefully I'll find one pretty quick. Also hoping P&W still has a few manuals laying around for it, I'd like to get it up and running before the next ice age.
 
You might check over on the practical machinist forum for a tailstock. If you find one you better buy a Lotto ticket.
 
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Thanks Hal, I just registered over there and am going to put up a WTB thread to track one down, and another thread to get as much information and input as possible on these lathes.

Jim
 
JerrySharrett said:
A 32" long 338 Lapua?? Wonder were they got the brass?
Click to expand...

Powder Valley, Third Gen, Graf & Sons or Sinclair with your FFL.

Midway, Amazon, Cabela's all the usual suspects for retail.

Or, "same place you get your PPC brass" if you prefer :)

I order them together, gener'ly, saves on shipping....

(that's "me" though, as opposed to "they.")

hth

al
 
alinwa said:
that's too frickin-cool-for-words

happy happy happy

al
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You're telling me! Having a cleaning party with a few buds to strip down all the grease and crud and get it in working order. Open invite to anyone who cares to come help, beer and food will be provided.
 
Jim, re: the beer, I'll not be able to attend but I can send you my mailing address;

Seriously though, you CAN chamber without a tailstock. Installing a DRO would be a great help if you can't find a tailstock.

With a DRO you can set up a reference point and use tool holders on your cross slide that hold, drills, reamers, etc if that makes sense.
The dro keeps you from having to dial in the above suggested holders each time.

Aloris and its clones make drop-on holders just for that purpose.
PS there are some good Aloris clones that are considerably cheaper.

http://www.mscdirect.com/product/03309622
 
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I'll second Jerry's advice re the DRO, they rock.

I've ordered 4 setups from DROPROS and am happy with them. IMO The ES-8A lathe setup with two axes @ 500.00 is must-have equipment and astoundingly accurate.

al
 
So let me get this straight, I don't have to have my cake in order to eat it too?! You're telling me that with the right tool post and tools, I can chamber as accurately as with the tailstock? This day just keeps getting better and better! I will definitely be looking into the DRO, I get the distinct feeling that it would be the difference between chambering like buttah with it and like curdled milk without it.
 
Jim Cox said:
So let me get this straight, I don't have to have my cake in order to eat it too?! You're telling me that with the right tool post and tools, I can chamber as accurately as with the tailstock? This day just keeps getting better and better! I will definitely be looking into the DRO, I get the distinct feeling that it would be the difference between chambering like buttah with it and like curdled milk without it.
Click to expand...

I can't answer for the mechanics of that not knowing the characteristics of your lathe drives but MY first impulse would be to install a DRO pickup on the top or tool (turret?) feed slide, also called the "compound," instead of trying to drive a reamer using the carriage wheel. That said, I do use the carriage DRO to cut my bolthead relief (Rem700/Stiller TAC/Pred style) and it's really easy to hit a thou.

DO use a pusher like Jerry shows!!! This is HUGE in my opinion. I think it would be a real tactical mistake to mount a sliding reamer holder on the toolpost.

al
 
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