nuther BP head bolt question

A J-head is held on by 4 1/2" bolts, as many of us know very well. I am planning to work on my extra J-head, which is at the moment braced up on a rolling
platform. J-heads are devilish awkward things to move, lift, or do anything with until they're properly mounted. But I have to work on this one, so I'm planning to mount it on an inexpensive engine stand, procured today for $25. First woops is it won't mount on the 4 fingers of the engine stand, they don't go that close together. So I'm going to make another mount plate, my engine stand mount plate just uses regular 1" pipe.
I'm wondering if any of you guys know the bolt pattern of these 4 bolts. I stuck a piece of steel under there and punched it using my transfer punches (there are those ubiquitous transfer punches again) but the pattern is really crooked and I figure someone knows the actual designed values. Anyone?
GWE
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Don't know the values, but you might consider buying a square bracket from an old tracer head, they usually bring about $25 on ebay.
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The hole position details are in the BP manual I have. If you want I can scan the page and email it to you or maybe you can find the manual online. Its page 5.2 in my manual.
Grant Erwin wrote:

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I have the BP manual. You are correct, there is a bolt pattern which I never noticed before because it is so small and sort of smudged. Even with 4X magnification I can't really satisfactorily read it. If you don't mind, would you confirm these?
All 4 holes are spaced 1-7/8" vertically from the center of rotation. The upper two holes are spaced 2-11/16" horizontally from the center. The lower two holes are spaced 2.218" horizontally from the center.
Thanks!
GWE
David Billington wrote:

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OK, after rechecking, it appears I was wrong, I'm mixing up the J and 2J bolt pattern. Here's what I now believe is correct:
The top 2 are spaced 1-7/8" vertically and 2-11/32" horizontally from center. The lower 2 are spaced 2.019" vertically and 2.218" horizontally from center.
GWE
Grant Erwin wrote:

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From my manual the J head and 2J2 head seem to have the same bolt pattern for mounting.
Grant Erwin wrote:

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Well, here's what I *know*. I drilled the bolt pattern to the second set of dimensions I posted and the plate fit perfectly. I drilled 1/2" holes. And in my manual (M-105K, the last and most recent Bridgeport manual) the hole patterns appear different for the J and 2J heads. Anyway, 'nuff said, I made the part, it fits, it's square and tight and right so thanks! - GWE (dimensions repeated:)
The top 2 are spaced 1-7/8" vertically and 2-11/32" horizontally from center. The lower 2 are spaced 2.019" vertically and 2.218" horizontally from center.
David Billington wrote:

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Grant Erwin wrote:

There may be different ways of measuring the bolt centers, but as far as I can tell, the main head casting is the SAME for both 1J and 2J heads.
Jon
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From my diagram the upper 2 holes are spaced 1 7/8" vertically above the centre. The lower 2 holes are spaced 2.019" vertically below the centre.
The upper 2 holes are 2 11/32" horizontally from the centre, although the left dimension lines are not clearly related to the hole in question.
The lower 2 holes horizontal spacing is as you give 2.218"
The numbers are quite clear in my manual.
The holes size is given as 17/32"
Hope that helps.
Grant Erwin wrote:

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On Wed, 02 Nov 2005 17:45:56 -0800, Grant Erwin

If no one has the answer..Ill go measure the spare 1J head I have in storage.
Anyone need a 1J head, no idea of whats wrong with it..looks to be all there. Has a 1hp pancake motor on it...IRRC.
Gunner
"Pax Americana is a philosophy. Hardly an empire. Making sure other people play nice and dont kill each other (and us) off in job lots is hardly empire building, particularly when you give them self determination under "play nice" rules.
Think of it as having your older brother knock the shit out of you for torturing the cat." Gunner
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idea of whats wrong with it..looks to be all

I'm desperateley seeking vertical capability at a bargain price. Can an adapter be made to hang that head on a Hardinge TM-UM? How many sheckles to purchase? Tom Remove pyrotechnics to reply by email.

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Tom, where are you located? I'm working on my spare Jhead because I want to convert it back to a 1760 motor and see if I like it better than the rebuilt one I'm using now (the older ones were better in some ways) but whichever one I choose, the other one will be available soon in Western Washington State.
It used to be possible to ship a J-head via that place that only goes airport to airport, I got it shipped out here from Pennsylvania for $200. Heavy buggers. But I think that air freight company (was it something express?) raised their rates gigantically so it may be a shocker to ship it.
Anyway, you are likely closer to Gunner (Taft, California) than me (Seattle).
Grant To email me, do NOT 'reply-to', rather visit http://www.tinyisland.com/email.html
Tom Wait wrote:

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I'm in southeastern Wisconsin, that place known to the rest of the world as the frozen north. Think beer, cheese and Harleys. Tom
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Tom Wait wrote:

You'd better consider the weight. Even a 1J head is plenty heavy. I don't know how big a Hardinge TM-UM is. But, a complete 1J must weigh close to 200 Lbs. The main casting with the quill in it has got to weigh 100 Lbs, then there's the belt housing and motor. The quill has about 5" travel, so you need to consider the optimum height to mount the head so you can do small work fixtured on the table as well as larger work in a vise. Depending on how much knee (or whatever design the machine uses for Z table travel) movement you have, it could become a limitation.
Taking this big head on and off the machine to convert from vertical to horizontal will require major disassembly or a shop crane. I can just barely lift the motor myself, due to the height over the floor. Handling the main casting with the quill still in it is at the absolute limit of my upper body strength. With oil and swarf all over it, it gets to be a real challenge. This is compared to a 90 Lb 6" milling vise, which I whip up on the table with just a little "oomf" sound.
Jon
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wrote > Anyone need a 1J head, no

to
don't
Lbs,
so
upper
A Bridgeport M head is a common addition to a Hardinge TM. In fact theres one up for auction on Ebay all set to go on a Hardinge mill, but I'm afraid the bids will go to the moon. Someone lucky SOB just won a Hardinge mill with an M head on it for $310. It was in NY, to much frieght for my blood. That's why I was curious about Gunners J head. I'm not savvy about the various head designs Bridgeport offers. Just looking for information, and a bargain. Tom
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Tom Wait wrote:

The M head is MUCH lighter! 1/2 Hp, higher speeds, but no lower speed. The M does not have a back gear or a power quill feed. The J head has both, as well as a VERY much larger quill and spindle. The M is available with Bridgeport C taper, MT3 and B&S #7. That limits you to 1/2" tooling, and not a lot of other special arbors are available, like flycutters, boring heads, end mill holders, etc. for these tapers. You can get almost anything ever invented in the R-8 taper.
If the M head is just about "right" for the Hardinge TM, I think you'd find the J head to be too large in some dimension. The distance from the mounting flange area to the bottom of the quill, and to the quill centerline are both several inches larger on the J head. And the weight increase must be 2-3x, also.
On the other hand, on a machine which CAN handle the weight and size differences, the J is a much more versatile head. I changed my round-ram Bridgeport from M to 1J, and have been VERY happy with the upgrade. The tooling advantage I mention above is part of it, but the performance of a boring head, and the ability to run at much slower speeds is also a plus. The slow speed is great when boring, using jeweler's slitting saws and flycutters. I could never get a boring head to work with the M head, without massive chatter marks. I had to grind down a boring head arbor's 3/4" straight shank to 1/2" to fit the M head, which may have been part of the problem. I replaced the shank with an R-8 one when I got the J head, and had no more chatter trouble.
Jon
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On Thu, 03 Nov 2005 20:57:23 GMT, "Tom Wait"

Tom..bad idea. Really bad idea. The J head is nearly 300 lbs all by itself.
Hummm...there was some sort of vertical head in one of the boxes brought by the show promotor of the Visalia show last month. I wonder if you could get a hold of him.... It was about M head size...
Gunner
"Pax Americana is a philosophy. Hardly an empire. Making sure other people play nice and dont kill each other (and us) off in job lots is hardly empire building, particularly when you give them self determination under "play nice" rules.
Think of it as having your older brother knock the shit out of you for torturing the cat." Gunner
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wrote > Anyone need a 1J head, no

to
Thanks Gunner, I'd be in your debt if you could score me a head that would work. Check this link and scroll down about halfway. There are two TM/UM's with vertical heads. Whats the big Bridgy on the left? Not that I want to try this, just curious. Tom

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On Fri, 04 Nov 2005 20:16:59 GMT, "Tom Wait"

Link????
<G>
Gunner
"Pax Americana is a philosophy. Hardly an empire. Making sure other people play nice and dont kill each other (and us) off in job lots is hardly empire building, particularly when you give them self determination under "play nice" rules.
Think of it as having your older brother knock the shit out of you for torturing the cat." Gunner
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Grant, could you explain this? Why would the pattern from the actual transfer punch marks be crooked? I mean, the holes are exactly where they are, are they not? So how can the design specs be more accurate than what you're physically measuring?
- Michael
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