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Thread: George Thomas "Universal Pillar Tool" on the cheap and easy?

  1. #11
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    another bit of Geo Thomas's excellent detailing. It stops the cotter from rotating, keeps it oriented properly. There is a 1/16 pin in the body (one on each side of the cotter) than engages in the slot. Otherwise where you have split cotters you sometimes have to fuss around a bit aligning the cotters to get a shaft into the bore. The slot and pins eliminate that.
    Last edited by Mcgyver; 12-29-2018 at 02:04 PM.
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  2. #12
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    Quote Originally Posted by BCRider View Post
    JT, that's sure a pretty little drill press. And clearly not far off GT's original inspiration for his UPT.
    ...
    After I found the second image of the little drill press, I was reminded that the whole head comes off with one lock screw in back.

    I could set it it up with an alternate head for the other uses, setting aside the drill press and tap guide uses, which are handled already. Of course I could probably as well just make another more dedicated item to handle those uses. Dunno
    1601

    Keep eye on ball.
    Hashim Khan

  3. #13
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    Quote Originally Posted by Mcgyver View Post
    another bit of Geo Thomas's excellent detailing. It stops the cotter from rotating, keeps it oriented properly. There is a 1/16 pin in the body (one on each side of the cotter) than engages in the slot. Otherwise you sometimes have to fuss around a bit getting a the shaft into bore where you have split cotters.
    If there was a way to spread the side of the cotter out from the middle it would self set itself. And wouldn't THAT be sweet?

    That's a lovely job you did on the sensitive drill head. I'm not really thinking that I'd even go with that as an option. I was thinking more of the other functions.

  4. #14
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    Quote Originally Posted by Tim Clarke View Post
    Hey Mcgyver, what's with the keyway in your split cotter?
    If you mean the brass clamping pieces to clamp the heah to the collum I would imagine a small end mill, or a slitting saw, or even a Woodruff Keyset Cutter. When build the UPT install the clamping pads in the arm for the head or table arm then finish bore the hole for the pillar. Then face off the inside face of the part t allw the pads to clamp against the pillar. Take the outside if needed. A swing in between the clamp pads so they release would be nice too.
    Forty plus years and I still have ten toes, ten fingers and both eyes. I must be doing something right.

  5. #15
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    Home made jobby here.
    Designed as i went along.
    Base is a Harley flywheel half.
    Best thing i've found it's use for is stamping the numbers in stuff, mainly dials.

  6. #16
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    Quote Originally Posted by BCRider View Post
    If there was a way to spread the side of the cotter out from the middle it would self set itself. And wouldn't THAT be sweet?

    That's a lovely job you did on the sensitive drill head. I'm not really thinking that I'd even go with that as an option. I was thinking more of the other functions.
    thanks....I was more trying to illustrate that with a bit of profiling and some paint, you can make make from barstock what the kit has as cast without much issue,

    not 100% sure what you mean about the cotter. The issue is they rotate and the pins stop that, solves it perfectly. I put a chamfer on the pillar and what minor amount the cotters may move in toward the centre is instantly corrected as the chamfer makes contact
    .

  7. #17
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    Quote Originally Posted by Mcgyver View Post
    thanks....I was more trying to illustrate that with a bit of profiling and some paint, you can make make from barstock what the kit has as cast without much issue,

    not 100% sure what you mean about the cotter. The issue is they rotate and the pins stop that, solves it perfectly. I put a chamfer on the pillar and what minor amount the cotters may move in toward the centre is instantly corrected as the chamfer makes contact
    And then we can rightfully claim that we made the tools from "BILLET ! ! ! !"....

    And the point of being able to make the parts from solid stock was not lost... at least I hope not.

    I was thinking a spring to spread the cotters. But I like the idea of limiting their travel so the usual chamfer or rounding wedges them apart automatically. Far better and easier at the same time.

  8. #18
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    I have not had a problem with split cotters spinning. They seem to align OK automatically by the wedge portions.

    I'd be thinking that the pin slot and wedge portions need to be aligned perfectly or else they will "fight" each other and jam up worse than ever. I suppose the pin slot can be oversize.

    Maybe if you follow the usual advice and make the cotter by putting it in place with pin slot and pin, then drilling through the hole for the standard, finally cutting apart, it would be inherently in line. But I generally just do an angle cut on the end of them as two separate pieces, which seems to make a good cotter that holds solidly.
    1601

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    Hashim Khan

  9. #19
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    Quote Originally Posted by J Tiers View Post
    I have not had a problem with split cotters spinning. They seem to align OK automatically by the wedge portions.

    I'd be thinking that the pin slot and wedge portions need to be aligned perfectly or else they will "fight" each other and jam up worse than ever. I suppose the pin slot can be oversize.

    Maybe if you follow the usual advice and make the cotter by putting it in place with pin slot and pin, then drilling through the hole for the standard, finally cutting apart, it would be inherently in line.
    lol follow the usual advice? I hope I am.....I could write the book on these things, in fact I have in detail described their manufacture. They're always (by me anyway) cut in situ and split afterward and then faced to length and of course the slotting and pinning is done before boring. And no, the pins are not used to the hold the cotter rigid for boring and the slot is not oversized. The pins stop the cotters from rotating in use and simply work. Split cotters without them can and do rotate in use (i.e. they are not aligned with the shafts bore when you go to install the shaft) which is less convenient.
    Last edited by Mcgyver; 12-30-2018 at 07:43 PM.
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  10. #20

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    There was an article in the HSM sometime in the last few years about building one from plumbing tees. IIRC, he machined out the threads and installed sleeves or plugs to get the meat he wanted around the ID.

    I just saw an alternate solution that might be even better. I was in the welding supply store today, browsing the racks, and there was a 3/4" heavy duty welding tee that's not threaded and has much thicker walls. Without actually going back and doing calculations, it looks like these would be a better start for less machining and flogging around to get what you need. Maybe next month I'll go back and get the ones I need.
    .
    "People will occasionally stumble over the truth, but most of the time they will pick themselves up and carry on" : Winston Churchill

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