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  1. #21
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    Quote Originally Posted by Mud View Post
    I bought my Rahn granite square at Small Tools Inc in OH. Picked it out of a large collection of granite items. I see they no longer have their used inventory online, only new tooling. Their warehouse is truly huge, they have lots of inspection equipment if you call they likely have what you want at a price you'll like.

    I noticed that they didn't have any used stuff on the website, thought they got out of the used tool biz.

  2. #22
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    Quote Originally Posted by machinistrrt View Post
    I noticed that they didn't have any used stuff on the website, thought they got out of the used tool biz.
    They have an Ebay store, but it's small. Their current site is pretty new, maybe they'll put used stuff up at a later date. I can't see how they would clear out that warehouse and scrap it all.

  3. #23
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    Don't do the bearing race as a circular parallel business myself. Instead, I use a 2 inch diameter x 1/2 inch thick disc of 1095, hardened 58 - 60 Rc. The faces have been surface ground as parallel as a good grinder hand could get them on a good surface grinder. Don't really know how much parallelism error there is, but the only movement in the needle of Ames 0.0001 inch per division dial gage mounted on a stationary stand is a subtle twitch when reversing the puck's sliding-on-surface-table direction of travel.

    I use the puck between the machine's table surface and a fixed dial gage to check table-surface parallelism error relative to the table-on-saddle and saddle-on knee ways. Yes, I slide the puck out from under the gage tip, move the table, and slide the puck back under the gate tip, for every move . . . but it isn't hard to not technically challenging, and it let me choose the measurement intervals.

    The same puck comes into play when tramming. The moveable puck allows me to pick a beam radius to suit the geometry of the machine, and, if the machine table isn't adequately parallel to the table and saddle ways, I can tram to the ways if that suits me.
    Last edited by John Garner; 04-08-2021 at 11:32 PM. Reason: correct wrong words

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    Use a precision square on the spindle, or if a bridgeport on the front of the spindle has a pair of milled notches where the stop adjust is. put some stock in and flycut at about four inches, slow spindle speed, fast feed and see if the cutter " Cat Eyes" if so then check Y axis same way, this is the best test as mill tables sag a lot

  5. #25
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    Quote Originally Posted by Lucaselef View Post
    Even if I were to use a bearing race for tramming I'm still in need of a master square to use as a reference to compare everything else too. There's no easy direct way to measure squareness so I'm need of a high quality square with proof/traceability of it's squareness to use to compare against.
    Unless you need the certs for government contracts, I would not spend the extra money on the high-end square.

    Some time ago I made my own cylinder square out of a large Diesel piston pin. (New Old Stock from 1920) About 2.5" dia and 6" long. Lapped one end it on silicon carbide paper, on a surface plate. Measured within .0002 over the 6" length, with a new Compac indicator and a grade B plate. Cost me a total of $40 and several evenings and weekends.

    That cylinder square is now the master for everything else, because it effectively carries the straightness of the surface plate around with it.

    Practical upshot of this is, the limiting factors for me was the grade B plate and a tenths indicator. If you need better than that, you should be prepared to spend a LOT of money and time with a controlled lab environment etc.

  6. #26
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    Exactly Pvat, and unless I missed it, all the OP said was he wanted one with certs and not that he had to have one. Want is fine and I'll usually buy the best in metrolgy I can afford because you can't add accuracy later. Needing traceable certs because your forced to have them if you want to even bid on the job is completely different. Tramming with a square is only a visual indicator of how somethings off and in which direction, but not how much. A B&S 558 cylindrical square could do the measurement down to some fairly fine numbers. But even that's not really needed since you just want as square as possible to the table. That's what an indicator can do for a lot less money and faster. For actual tramming of the head on something like a BP't I'm always going to use the almost universally adopted indicator method. I'd have the vise and head done before the first axis is dialed in using a square against the spindle. Tramming however is only correcting the spindle in X,Y. There's a lot more checks to verify on any mill unless it's already been checked. A granite or even cylindrical square would check how true and square your X,Y,Z table travels and Z on the spindle is. But even then your going to need an indicator tracking against the squares surface to measure any deviations and where they might be. So the OP really needs to define if it's a want or a definite need.

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    One of the shops I worked in had a cyl square where one face was perpendicular and the off side was not. (about 3" dia and 10" tall) The idea was you could put the cyl down on the non perpendicular face and rotate it around till you got no light twixt it and the DUT. And then read the deviaion off of an engraved scale on the cyl. That little feature made it real easy to shim pieces on the grinder to get them truly squre.

    Sorry I have no idea who made,

  8. #28
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    That was probably a B&S 558 cylinder square. Not made anymore but very handy if you can find one in decent shape on Ebay etc. It took me over a year to find one in the condition and price I was willing to pay.

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    Hi All:
    I'm going to be a bit contrarian here and make the following claim:

    If my main objective is to tram a mill, a 6" granite angle plate can't be beat.

    I just run it up against the side of the quill and shine a light from the back.
    The angle plate is wide enough that I don't have to get right on the center plane of the quill like I would with a knife edged master square...I can just push it against the quill and it'll touch at the equator even if the quill is still tilted in the other, orthogonal plane.

    It shows me instantly which way the quill is off in whatever plane I'm interrogating.
    It shows me in real time how much to move it to make the hairline of light vanish.
    I can see in real time how much it moves when I tighten the bolts (and it always does).
    I can detect 2 tenths in 6" instantly and without trying hard...the parallelism of the hairline of light is a very sensitive measure of squareness.

    It is a thousand times faster and less frustrating than fucking around sweeping the table.
    It's also just as accurate, and I've proved it to myself often enough by sweeping a clock after tramming with the angle plate.

    Of course it requires that the quill be cylindrical and not conical or worn to some weird shape.
    It requires that the quill be a close fit in the head and not free to flop around.
    It requires the table to be flat, not beat to ratshit and the top to be coplanar with the machine movements.
    It also requires a good but not spectacular granite angle plate.

    Mine is a 6" Starrett that I've had and used for 30 years.

    Cheers

    Marcus
    Implant Mechanix • Design & Innovation > HOME
    Vancouver Wire EDM -- Wire EDM Machining

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  11. #30
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    Quote Originally Posted by implmex View Post

    Of course it requires that the quill be cylindrical and not conical or worn to some weird shape.
    It requires that the quill be a close fit in the head and not free to flop around.
    It requires the table to be flat, not beat to ratshit and the top to be coplanar with the machine movements.
    It also requires a good but not spectacular granite angle plate.
    Wow -- that must be some fancy mill you have with a flat table and a close-fitting, cylindrical quill. We should ALL be so lucky;-)
    Great idea, though, using the granite right angle. You're correct; far less f*#king around.

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    Hi specfab:
    You wrote: "Wow -- that must be some fancy mill you have"

    Yeah, the difference between what we fantasize we have and what we actually have is often quite astonishing.
    We pretend to ourselves that our quill is cylindrical, our table is flat, the top is coplanar to the travels and other ridiculous assumptions all the time.
    That's why I laugh when people brag they're working to a half thou' on a Bridgeport.

    So I throw in the caveats to be rigorous, and tram my mill the convenient way, happily assuming all these things are true even when I know it's all actually bullshit.

    Cheers

    Marcus
    Implant Mechanix • Design & Innovation > HOME
    Vancouver Wire EDM -- Wire EDM Machining

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  14. #32
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    When I need to work to a half-thou on MY Bridgeport, I just cover up the Bridgeport name with a magnetic Moore nameplate. It is simply a mental adjustment to make one's knee mill into a jig bore....;-)

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    OOOHHH that was a good one specfab...I almost spit my coffee on the keyboard.

    Reminds me of the tight assed toolbreakers I worked with back in the 1970's.
    All were soooo tool proud, and would react sniffily if you showed up with a mere Mitutoyo.
    Etalon was THE brand back then...if you had Etalon mikes you had arrived.

    So one wag in a toolroom I worked in who hated this sort of shit, made himself a drop gage stand out of a flame cut plate of 4140.
    He surface ground it top and bottom (but not the sides), bolted on a 3/4" ejector pin and then TIG welded the letters "ETALON" on the front.
    Man the sight of that thing could start fistfights and he loved every minute of it.

    Cheers

    Marcus
    Implant Mechanix • Design & Innovation > HOME
    Vancouver Wire EDM -- Wire EDM Machining

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  18. #34
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    Beautiful -- sort of the machinist's version of a live-edge coffee table....

  19. #35
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    Quote Originally Posted by implmex View Post
    OOOHHH that was a good one specfab...I almost spit my coffee on the keyboard.

    Reminds me of the tight assed toolbreakers I worked with back in the 1970's.
    All were soooo tool proud, and would react sniffily if you showed up with a mere Mitutoyo.
    Etalon was THE brand back then...if you had Etalon mikes you had arrived.

    So one wag in a toolroom I worked in who hated this sort of shit, made himself a drop gage stand out of a flame cut plate of 4140.
    He surface ground it top and bottom (but not the sides), bolted on a 3/4" ejector pin and then TIG welded the letters "ETALON" on the front.
    Man the sight of that thing could start fistfights and he loved every minute of it.

    Cheers

    Marcus
    Implant Mechanix • Design & Innovation > HOME
    Vancouver Wire EDM -- Wire EDM Machining

    In my industrial plant and toolroom experience it's the ones who can't take a joke who wind up at the bottom of the dogpile. Just hard to resist tweaking for that response.

    But the jokes can't be actually harmful to persons or tools. The Etalon gauge stand is an outstandingly good example - notwithstanding that I have a set of Etalon mics. I'd have that proudly in my shop.

  20. #36
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    Hi TGTool:
    Like you I acknowledge that Etalon tools were exceptionally well made and certainly I have no objection to owning them, looking after them, using them with pleasure, and being proud of them.

    What used to chap non Etalon owner's asses in the toolroom was the nose-in-the-air attitude of the extra anal, and they all used their "superior" tools to try to put down anyone who wasn't part of the club.
    It managed to get pretty heated at times, and this was a highly creative way to push back.

    The perpetrator made a fair number of bitter enemies but also a fair number of enthusiastic supporters over that stunt.
    I left that job soon after, but I never really forgot it and when specfab talked about sticking a Moore logo onto a Bridgeport and pretending brilliance, it all came back.
    So I thought I'd share...glad it was appreciated!

    Cheers

    Marcus
    Implant Mechanix • Design & Innovation > HOME
    Vancouver Wire EDM -- Wire EDM Machining

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  22. #37
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    The snobbery is always an annoyance, but if they're also excellent craftsmen you have to give them some grudging respect.

    At the other end is the guy who thinks he's hot stuff because he's got the expensive tools but is really a mediocre craftsman. Nothing like either of those in my experience on the bench. Of course there were better and worse personalities and greater and lesser skills and knowledge. What I do remember from years earlier was working as an auto mechanic in a foreign car repair shop. They hired one guy who brought with him the two stack Snap On toolboxes full of tools. Everybody had their own modest toolbox and the shop had a few specials, but if you needed something someone else had you could usually borrow if you asked nicely and took care of the tool. The Snap On kid's tools didn't get loaned out to nobody. You didn't touch his toolbox. I caught hell one Friday as we were sweeping up for the weekend because I had stood the push broom up leaning against the back of his box.

    Anyway, so there was an Alfa engine in for a rebuild. He begged for the job because that class of a car was a good fit for him as a class mechanic. All done but it didn't last long. He'd put Loctite on the backs of the main bearing shells because that's the way they did it on the army trucks. Inadequate heat transfer burned up the bearings and crank. Sigh!


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