Pratt & Whitney WW2 Special Ops Mill

defdes · Dec 22, 2017

Hi all, would anyone be able to give me some information on this machine? I inherited it from my grandfather who was a chief engineer for Indian Motorcycles from 1940-1944. I posted a query about it on a site in the early days of the internet, and someone told me of a specific function that it had that required drilling on an X & Y axis.
My second question is about the quill(?), it requires a drill bit or a drill chuck with a 3/8" shank, but my grandfather had a lot of end mills and collets which I assume he used with this machine though it doesnt look like one could use an end mill that didn't have a 3/8" shank, am I missing something?
And finally, the spindle has a few thousandths of run out which one you are holding a chuck and bit in, equates to much more, any ideas on how I could straighten that situation out?
Here it be:

morsetaper2 · Dec 22, 2017

It looks like a P&W jig bore machine? And the plate on it makes me think Springfield Armory was the original purchaser. And the Indian Motorcycle plant wasn't too far away from the Springfield Armory. Visited both of those places maybe 10 or 12 yrs ago. As P&W jig bores go, that one is rather small.

Jig borer - Wikipedia

defdes · Dec 22, 2017

That was it, thanks so much. I was able to use it for modest aluminum milling with a 3/8" end mill but as the Wiki said, not it's real intention.
If anyone else could give me info on a potential way to straighten out (and disassemble) the spindle it would be most helpful.

SIP6A · Dec 22, 2017

It's a drill press that somebody has mounted an X - Y table on.

As for the runout all I could suggest from the photo is take the end of the spindle apart and stone all the burrs off of everything.

Is what looks like a chuck able to come off the machine? If so that's probably where your runout is coming from.

It was probably set up to do one job.

johnoder · Dec 23, 2017

Accuracy For Seventy Years (1930) shows early 1A, 2 and 3A Jig Bores on page 75, not similar

Later jig bores were 1 1/2B, 2A and 3B - much larger and more complex than the thread's subject

Precision Tools (1911) has no jig bores or single spindle drills - though it is known the #2 jig bore appeared in 1914 (Thumbnail)

morsetaper2 said:
It looks like a P&W jig bore machine. And the plate on it makes me think Springfield Armory was the original purchaser. And the Indian Motorcycle plant wasn't too far away from the Springfield Armory. Visited both of those places maybe 10 or 12 yrs ago. As P&W jig bores go, that one is rather small.

Jig borer - Wikipedia

JST · Dec 23, 2017

SIP6A said:
It's a drill press that somebody has mounted an X - Y table on.

......

You can see the DP table under the X-Y table.

I use an X-Y on one DP, very handy. But a DP with X-Y is not really a jig borer.

Andy FitzGibbon · Dec 23, 2017

It looks like there's some sort of adapter in the spindle to go from the 3/8" tooling to a (probably) Morse taper. I'd knock the adapter out and see if the runout disappears.

Andy

defdes · Dec 23, 2017

This is what it looks like under the cover, it looks like that spindle is solid (stepped) and continuous. I haven't opened the top of the head yet, but I would imagine that the spindle is a long rod and held at the top of the head by a nut in compression against the bearings shown.

SIP6A · Dec 23, 2017

defdes said:
This is what it looks like under the cover, it looks like that spindle is solid (stepped) and continuous. I haven't opened the top of the head yet, but I would imagine that the spindle is a long rod and held at the top of the head by a nut in compression against the bearings shown.
View attachment 215959

What's the hole in the end of the spindle? straight? tapered?

JohnEvans · Dec 23, 2017

Yes to a drill press ! Crank the quill all the way down and see if there is not a slot for a drift to remove a taper shank tool.As said a good chance the spindle is set up for Morse taper tooling [drill bits].

Mike C. · Dec 24, 2017

Agree to check to see if that's a MT Weldon type holder in the spindle. The reason for your runout is the setscrew in the side of the tool holder. There has to be a thousandth or more of clearance in the hole or you couldn't get the 3/8" cutter in the 3/8" hole. It's probably more like .377 from years of wear. When you tighten the screw, it shoves the cutter against the far side of the holder and you get runout. Had the same problem with a 1 1/4" Weldon brand air bearing fixture for my tool and cutter grinder. Noticed it was sharpening everything off center, then it hit me why. Got a 1 1/4" straight shank ER40 collet chuck and used a ball peen hammer to ding up the side opposite the setscrew. Just a couple of tweaks put me at under .0002 runout, as measured with a tenths indicator. The ER40 chuck just lives in the air bearing fixture now.

defdes · Dec 26, 2017

SIP6A said:
What's the hole in the end of the spindle? straight? tapered?

It is straight 3/8".

defdes · Dec 26, 2017

While I agree that some of the run out is caused by that single set screw (I thought about putting in 2 more and centering it like a 3 ja chuck) but I measured some of the run out AT the the set screw, which lead be to believe that it was the at the end of a longer shaft that cut slightly bent.

Monarchist · Dec 26, 2017

defdes said:
While I agree that some of the run out is caused by that single set screw (I thought about putting in 2 more and centering it like a 3 ja chuck) but I measured some of the run out AT the the set screw, which lead be to believe that it was the at the end of a longer shaft that cut slightly bent.

Any way you fix it, when DONE, I think Mike's experience with getting an ER (or TG) onto it, running near-as-dammit dead-nuts true, then just leaving in place would be wise.

It is too light to need the anti-pushback//anti-pull-out feature of a Weldon-pattern side-lock as it is NOT a mill. Drill or jig bore, it was built for inline stress, not side-stress.

If you NEED a mill, more better to trade for one. They make far better substitutes for either jig bores or drill presses than the other way 'round. And.. they are still "real" mills, built to mill, however great or humble.

defdes · Dec 26, 2017

Monarchist said:
Any way you fix it, when DONE, I think Mike's experience with getting an ER (or TG) onto it, running near-as-dammit dead-nuts true, then just leaving in place would be wise.

It is too light to need the anti-pushback//anti-pull-out feature of a Weldon-pattern side-lock as it is NOT a mill. Drill or jig bore, it was built for inline stress, not side-stress.

If you NEED a mill, more better to trade for one. They make far better substitutes for either jig bores or drill presses than the other way 'round. And.. they are still "real" mills, built to mill, however great or humble.

Thanks, yes you are right, I'd like to get this running as true as I can, then just buy a small Bridgeport. FYI no slot for a drift.

Monarchist · Dec 26, 2017

defdes said:
Thanks, yes you are right, I'd like to get this running as true as I can, then just buy a small Bridgeport. FYI no slot for a drift.

FWIW-not-relevant, my 7.5 HP Alzmetall AB5/S has BOTH a drift slot for its #5 MT AND the slot for a locking key, as used on hor-bores. Quill size is as stout as a small H-B as well, and yet..

..it was designed as a drill press. It IS a drillpress. And even though it LOOKS as if it would eat a Bee Pee's lunch if but given an X-Y table? A mill it is not, nor ever will become.

As may prove the case with this machine of yours, my tiny Walker-Turner DP still gets to make more holes. Just handier, y'see.

Paolo_MD · Dec 27, 2017

ould you check these three simple things...

Defdes,
From your pictures it is quite clear that the 3/8" holder is an adapter and not part of the spindle.
Here I have edited two of your pictures, adding letters and arrows in order to simplify the communication.

First, an adapter can be held in via a drawbar (pulling-in a tapered portion) or a simply by a taper. The third, less likely, option is for the adapter to be screwed-in (e.g. Moore jig borer tooling, Master Mill/early Versa Mill tooling, etc.).
First, I'd like you to inspect the top of the spindle (A) to see if, by any chance is either hollow (i.e. it has room to put a rod to knock off the tooling) or has a threaded rod with a nut or similar: this would likely be a draw-bar. Once the nut is loosened a couple of turns, you can rap the rod downward with a dead-blow hammer to knock off the adapter.
Alternatively, if the spindle is solid, look carefully at the quill containing the spindle for any slot where you can see the spindle. Possibly, it is located in the keyway B. If this is the case, slowly rotate the spindle and you'll see that soon or later a slot will appear (move the quill up and down, so that you inspect also the part now covered by the quill support).

If everything above fails, try to unscrew the adapter: it could be rather tight.

Lastly, right now, with the buggered adapter in the spindle, the only fair runout measurement you can take is at "C".

Paolo

tdmidget · Dec 27, 2017

Those bearings visible in the pic appear to be bone dry.

defdes · Dec 30, 2017

Excellent info, thanks. The spindle cap is solid, there is no place for a rod a la a Bridgeport or anything, there is no anywhere for a wedge to go that I can see. I'll have to check, but I believe I saw a collet for an end mill that had an opened threaded hole on the end which would lead me to your last idea. odd that there doesn't appear to be a place to lock out the spindle to remove the adapter.

Pratt & Whitney WW2 Special Ops Mill

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