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    Default Master Square or Tri square?

    I'm looking for a master square for my shop. Something with certification proving the measurements of squareness. I plan to use this to tram a mill and also use for setting up a squareness comparator rig using an indicator to make other tooling square. I want it to be the go to reference for squareness.

    So far I've been looking at the standridge/precision granite Tri squares and master squares. The master squares only seems to be about $150 more than the Tri square. Is there any reason I wouldn't want to have 2 more measuring faces of the 5 sided square? I understand it will weigh more, but I'm not super concerned about that as it will mostly sit near the surface plate.

    Also, is there anyone else making traceable units besides standridge/precision/starrett? Those 3 all seem to be ~$900+
    I'd also consider a steel/cast iron one, however i didn't see any that weren't super thin which wouldn't be stable enough for tramming.

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    Quote Originally Posted by Lucaselef View Post
    I'm looking for a master square for my shop. Something with certification proving the measurements of squareness. I plan to use this to tram a mill and also use for setting up a squareness comparator rig using an indicator to make other tooling square. I want it to be the go to reference for squareness.

    So far I've been looking at the standridge/precision granite Tri squares and master squares. The master squares only seems to be about $150 more than the Tri square. Is there any reason I wouldn't want to have 2 more measuring faces of the 5 sided square? I understand it will weigh more, but I'm not super concerned about that as it will mostly sit near the surface plate.

    Also, is there anyone else making traceable units besides standridge/precision/starrett? Those 3 all seem to be ~$900+
    I'd also consider a steel/cast iron one, however i didn't see any that weren't super thin which wouldn't be stable enough for tramming.
    I HAVE squares of that calibre. B&S. Vis (Polish), and two sizes of pain-in-the-ass "cylindrical".

    The nuisance to handle cylindricals are the "references" here. Good enough I need not give a damn about keeping them in certs no one is paying me to mess with, they spend 99.999 percent of their boring lives in a cabinet, boxed in VPI paper wrapping. You want a "reference"? Give those a thought. Squat and HEAVY buggers are too stupid to be forever falling-over. That part, I DO like!

    Even so, I'd no more use any one of them to tram a MILL than I'd use a Mark 42 Radar Gun Director to run the mowing path of an ignorant lawnmower.

    Mills that can even BE "trammed" at all or NEED it (not all do..) MOVE.

    Rather a lot! Unless they are not doing any useful work.

    The "exotic" method is to place a salvaged bearing outer race on a well-kept table and sweep the f****r with a DI mounted to the spindle.

    There are simpler ways, too. An ignorant parallel in decent condition works well ENOUGH.

    Any of those methods with a DI, not a square, will provide waaay more information than the "tramming" you can do with said information can be expected to HOLD ... once you put the mill to doing actual metal removal.

    Any "decent" shop square or even a top-end carpenter/cabinet maker's square can actually do a right decent job, too. Reverse-check even a poor square, split the dif and move-on.

    Even framers and drywall hanger lads do THAT much. Ever wonder what those lines on the wall were from? They carry tools about, one job to the next. S**t gets pranged. So they start the job? They CHECK levels and Tee squares for damage. Takes less time to do than describe.

    We JF DEAL with that wear, damage, and imperfection situation. Because "metal removal" is why we HAVE a mill. They make s**t-lousy decorative wall art. Too bumpy by half.

    Even a Moore or SIP Genevoise is still only made of metal. They move less. "Less" is still a finite number.

    It is all we have. It is all we ever DID have. It is all we ever WILL have.

    It is even "all we really need." TONS of chips get made on "acceptable" parts, even on a shakey-flakey BirdPort that is more badly worn than gives it any RIGHT to still earn a crust at all.

    Mill hands compensate for all that s**t. And more.

    It's what they PAY us for.
    Last edited by thermite; 04-05-2021 at 03:30 AM.

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    Quote Originally Posted by Lucaselef View Post
    I'm looking for a master square for my shop. Something with certification proving the measurements of squareness. I plan to use this to tram a mill and also use for setting up a squareness comparator rig using an indicator to make other tooling square. I want it to be the go to reference for squareness.

    So far I've been looking at the standridge/precision granite Tri squares and master squares. The master squares only seems to be about $150 more than the Tri square. Is there any reason I wouldn't want to have 2 more measuring faces of the 5 sided square? I understand it will weigh more, but I'm not super concerned about that as it will mostly sit near the surface plate.

    Also, is there anyone else making traceable units besides standridge/precision/starrett? Those 3 all seem to be ~$900+
    I'd also consider a steel/cast iron one, however i didn't see any that weren't super thin which wouldn't be stable enough for tramming.
    That's not needed and more so almost unusable in real life situations unless you have one of those fancy machines with adjustable ways. I saw A LOT of machines in me life and saw only two or three of those. Memory serving, all of Russian manuf.

    You have an EXCELLENT post from Thermite - do exactly that. Find yourself a conveniently sized ( >4" ) outer bearing ring. Ask a g/box repair place for some large scrap. If made by a quarter decent manuf the ring will be flat and parallel within vanishing tolerances, WAY over a trammable machine might need. If you feel that's not good enough you can lap it on a piece of CI within 1 millionth or so, no intelligence or special tooling required. The end result of all this is that you'll be able to drill/bore/face DEAD square to the table at least for an inch or two. You can NOT achieve the same PERFECT result with a cylindrical or 90 degs square short of some very serious irritation and even then, IF SO. The ring method, if intelligently used keeps the machine VERY close to working position. The others keep it FAR from that.

    You will notice that the ring method replaces certain suppositions ( machine in good condition and square to start with... ) with certain easy to satisfy certainties : table under the ring is flat and spindle bearings are THERE.

    On the other hand I use(d) often a square to re-set the tables on my Deckel or Maho mills. But it was a pretty ordinary square with 2-3 places where the error was marked. One often forgets the base of the square needs be strictly parallel with the table - i.e. must sit on an adjustable straight edge.

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    Quote Originally Posted by Orbital77 View Post
    The end result of all this is that you'll be able to drill/bore/face DEAD square to the table at least for an inch or two. You can NOT achieve the same PERFECT result with a cylindrical or 90 degs square short of some very serious irritation and even then, IF SO. The ring method, if intelligently used keeps the machine VERY close to working position. The others keep it FAR from that.
    An even BETTER post, thanks!

    But right HERE is where "compensation" already enters!

    You niggle, nudge and dead-blow-tap to line the DI on the God of the spindle up to near-zero deviation.

    And then? AS you start to tighten the clamping fasteners?

    EVERY machine moves, and moves a tad DIFFERENTLY than the one off the line, adjacent serial number, even if BOTH of the f*****s are BRAND NEW and still "Virgin", never yet made first-chip!

    Which they are basically "never" in real-life.
    Quite the reverse. Worn out hoors!



    NOW you learn to "compensate" so the DI will be dead-nuts AFTER the clamping is completed.

    In the fullness of time, you will come to "marry" that machine-tool, and hold it's personality and quirks in YOUR memory so it becomes second-nature. Different machine or new job? Introduce yourself to the ways of a new partner.

    "First comes good."

    "THEN comes fast"

    Now you are EARNING your pay, no longer just a break-even student.

    You KNOW you have crested the hill when a Foreman who came up through the ranks off the shop floor himself, now twice your age - or a LOT more, yet - ASKS you instead of TELLING you, and then discusses and agrees a reasonable way to tackle a challenging tasking.

    You have demonstrated that you UNDERSTAND, and have the knowledge and judgement worthy of his TRUST.

    Between your ears. Skill between your HANDS follows, it does not lead.

    No time to get cocky.

    You still have MORE to dig out of his brain and transfer to your own one! And he had best not be your ONLY source, either! Some crotchety Old Fart is the shop's most notorious ASSHOLE? Yah, well.. he knows SOMETHING you do not YET know!

    How can you "xerox a copy" and make use of it? And does he know MORE than "just the one new thing?"

    Useful skill you wouldn't want to have to put into a book? I learnt to IGNORE the NASTIEST of "denture breath" and even flying spittle!

    Got me fast-tracked tool & die training from a Master's, Master's, Master in his mid and late 70's. Then another in his 80's, and then .. the only "A" on the final and one of two for the course, one of the finest, most expert, and decades-long experienced minds in Money and Banking of the age. Brilliant guidance. If one could but STAND the SOB!

    Well. It wasn't as if I had to have SEX with any of that lot, was it? It was America and ancient grease. Not ancient Greek in Greece!



    What a(ny) human can "do" is largely a product of what that human "has come to KNOW". or is willing to learn NOW. Because he knows he will be better-off.

    "Learn" by whatever means, and from any and EVERY source within reach of his ever-acquisitive mind.

    So long as it is FASTER than the OTHER guy who wants access to the nicest looking food and the tastiest wimmin.

    Or is it the reverse? Can't remember EVERYTHING, can one? Keep it simple.

    BOTH will do just fine!



    Anything LESS important.. money and similar s**t... will just happen to fall in line with minimal fuss.

    Really. It just does when you are too busy staying happy-healthy learning and growing to stop to whine ... and blame some other guy.. if not "management".. if not the whole dam' universe.

    And just which one of those three actually gives a measureable shit about YOU?

    Would you believe the SAFEST odds ..... are with "the universe"?

    If only because it is less resistant to change.


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    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.

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    It's unclear what type of mill you're trying to align, the previous posters seem to be assuming it's a turret mill.

    For levelling/tramming a VMC, a nice square is important, though personally I find the granite ones heavy and cumbersome. I have a 24" grade A Moore & Wright blade square that I've checked is out .0001"/20" (50uin/10"). This is good enough for my machines but you're right the narrow indicating surface isn't ideal. I'd still prefer it to granite or a scraped reference (the scraped reference is annoying because of all the low spots).

    If it's a bridgeport, sweeping the table for tram is a totally valid way to align the machine, partly because the quill travel is naturally well-aligned to the spindle axis and the quill travel is very short. If you're feeling picky about aligning to the ways rather than the table, you can hold a gage block in the vise and move the table while rotating the spindle so that you don't have any table/way misalignment.

    Not worth talking about aligning a machine more complicated than a bridgeport or basic VMC here since it gets so much more complicated quickly.

    Lastly, it's very easy to make an arbitrarily precise square starting with a surface plate, 246 block c-clamps, and a large good quality parallel. This is covered in many places (one example among many: Its Hip to be square - YouTube). If this is an infrequent-use item for calibrating other metrology tools, you can cobble one together in 30minutes rather than buy the granite unit.

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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.
    The bearing race has more use than you might have considered. Suppose you are working an angle. Maybe a complex part.

    On a BirdPort "style" vertical, you have swivel AND "nod". On my Quartet, swivel only. So I'd be using a trunnion ... or angle plates set with a sine bar.

    Now I need the spindle axis dead-nuts perpendicular to a surface that has no relation to "square" of itself. I can only get a small square even into the space where I want to do the movement. And that "PLACE" is where it matters.

    Dropping Z axis to make daylight is going to not only introduce a different wear zone on the ways, it will put me further off the line of the extended legs of the square as well. Doable? surely. Optimal? Hardly.

    Surely one needs good squares.

    I use mine "mostly" to either do directly - or to "assist with" by vetting other goods - precise LAYOUT.

    Old Skewl blue, red, or white Dykem surface spray and carefully scribed lines, "etc".

    The other major use is for assessing a machine tool's ways & c. to determine how much wear-error I need to "JF deal with".

    Or - maybe - prepare to reduce. I'm lazy. I try to just not.

    Compensation is not that hard when you never HAD a decent machine and ALWAYs had to do it. BFD. That applies to about 95% of craftsmen of my era, if not forever-and-always!




    IF, then, correction is to be undertaken? One or more good squares become as important as my levels.

    Another use has to do with setting up to cut tapers. One of my lathes has a TA, the other two not. BFD, one vets a TA, regardless, "trust but verify" style. 1-2-3 and 2-4-6 blocks are "squares" too. Or surely need to be!

    So yes, you need good squares, several, or even "many". Some of my most crucial are TINY, and see a hundred and more times as much use as the "long-legged" ones in fine wooden cases they seldom come out of.

    Same as all other metrology. Work comes in many sizes. The goods have to cover the range.

    But no, mere "possession" is not the same as getting a(ny) specific "outcome".
    You also need to follow the timeless advice of B.C. Forbes:

    "With all thy getting, get thee understanding."

    Not just assumptions. Not just narrow "cases".

    "Big(ger) Picture" rather.


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    Tram the mill as described above. Get it as good as you can, but remember, it's freaking mill, not an interferometer! You can confirm squareness of a block or similar using the classic indicator stand with a ball in its crotch. If it's parallel, do both sides and split the difference. No need for fancy certs.

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    I have a Rahn tri-square, it has a key on one face that can be placed in a table slot. I find that handy.
    There are also cylinder squares, they seem inexpensive for the precision level.

    136944d1429069083-wts-magnetic-cylinder-square-18218_409321455912009_7521702050824040544_n.jpg

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    Quote Originally Posted by Mud View Post
    There are also cylinder squares, they seem inexpensive for the precision level.

    136944d1429069083-wts-magnetic-cylinder-square-18218_409321455912009_7521702050824040544_n.jpg
    That, they surely are!

    The other part is actually funny.

    Their immense surface area means you ain't all that likely to "wear one out".. nor even find it hard to work around a set of scars from dropping the heavy bugger in between the bulldozer tracks.

    "Funny" because they are such a b***dy nuisance to handle (see any HANDLES?), even on a surface plate, that their greatest risk of abuse or neglect is .... forgetting to be bothered even taking them out of the box or remembering WHICH cabinet the box was last placed into!



    PS: One style has the off-end ground to a precise angle NOT square. Those who need that understand the WHY of it, and why they might have more than one, seldom used or never.

    The best of metrology goods always have more than just the one "obvious" use.

    Then the clever-devil craftsman adds the other many, many off his own flavour of necessity.


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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.
    Every 2 years or so I make on order something similar to this :

    Squareness measurement - YouTube

    but somehow more "sophisticated" and fully adjustable. Will split a micron on 10" effortlessly.

    I NEVER EVER needed one and afaik neither did my clients. Just a fancy toy. On 2nd thought, the fact the shaft is DEAD straight does come handy for other things, now and then. In case you wish to order one, the shaft is nitrated full hard bearing steel - tapping the ends for M8 is whole different kind of entertainment.

    N.B. You still need need a perfectly flat surf reference.

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    Over the years i've made several for self and others by sawing up CI angle plates and scraping the loose sections. Include the webs. IOW usually 2 per plate. The remaining bits have other apps as raw material for other gages, or for parts.

    So long as a surface plate is used for flatness, square can be proven by various methods describe above by other posters.
    One method, assuming large enough span indicators, gage block stacks, or large size micrometers can include tooling cylinders arrayed on a suitable flat T-slot table such as a planer, or large shaper table, & geometry.

    My first machine tool related purchase ever, was a granite knee. I thought the bid was for the surface plate & the knee, but only won the knee and even then realized it was the better resolution. Purchased another later, similar circumstances. Usually, from what i've seen, they are cheap because very few people including machinists have much comprehension that there is any utility for one.

    smt

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    I'm fully aware of their utility, or really, their necessity. I'm just having a hard time finding a quality one that isn't insanely expensive. Also trying to figure out if the master square is the way to go since it can be self checked and isn't much more money.

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    Any square can be self checked on a surface plate. The sequence depends on what surfaces it offers to work with. Two parallel surfaces that are square to a third face are the easiest, but even two right angle faces can be verified with an indicator and without an outside square reference.

    IMO, how fancy you get and how much you pay will depend on how you evaluate two factors - how often will you use it for checking, and what value you put on the pleasure of owning. I've bought mics that were more than utility required because they were a thing of beauty and a pleasure to use, for instance, and wouldn't begrudge anyone that.

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    Quote Originally Posted by Lucaselef View Post
    I'm fully aware of their utility, or really, their necessity. I'm just having a hard time finding a quality one that isn't insanely expensive. Also trying to figure out if the master square is the way to go since it can be self checked and isn't much more money.
    A granite cutting / polishing business could chop one ( 12") for you within the hour. One leg will be DEAD flat and if the machines are half decent the other leg will be just fine and within 1 thou off square. Some diamond powder from India, a piece of CI and lots of elbow grease and you could split a tenth in one afternoon. If you want it done by other people and properly "certified" you'll pay...

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    I considered getting a cheap import and lapping it my self. Problem is, I'd need a 12" master square to use for measuring my work. And we're back to square 1 lol

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    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.

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    Quote Originally Posted by Lucaselef View Post
    I considered getting a cheap import and lapping it my self. Problem is, I'd need a 12" master square to use for measuring my work. And we're back to square 1 lol
    No, YOU DO NOT. That is what was explained to you. Read post #14, ask for clarification if needed.

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    I understand what method they're talking about, however I'd still need a 12" parallel which I do not have. Even if I did - taking 2 indicator readings, setting the indicator to a third and then trying to account for any parallel error has too many steps which could induce error. Its good for a reference check, but I wouldn't use it to qualify a master square.

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    Quote Originally Posted by Lucaselef View Post
    I understand what method they're talking about, however I'd still need a 12" parallel which I do not have. Even if I did - taking 2 indicator readings, setting the indicator to a third and then trying to account for any parallel error has too many steps which could induce error. Its good for a reference check, but I wouldn't use it to qualify a master square.
    Well, I am glad things are clear.


    The ONLY thing you really need is a flat surface. The flatter, the better. Can be made with simple tools, not worth the trouble. Do not hesitate to spend some money in that direction. Then, ALL the other things discussed here can be easily made. Takes a bit of work but the result can be as good as you wish it ( or almost...) and CHEAP.

    Anyway, I wish you the best


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