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  • lazlo
    replied
    Originally posted by John Stevenson View Post
    Got a few CAD programs here and not one can thread worth a damn.................
    LOL! -- that's the ultimate answer to standardization. As one of the Electronic Leadscrew packages advertised, you can thread in Inch, Metrich, or Klingon

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  • John Stevenson
    replied
    Got a few CAD programs here and not one can thread worth a damn.................

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  • J Tiers
    replied
    Originally posted by boslab View Post
    But notably Metric tried to shoot itself in the foot when starting like specifying metric threads in a whole range of sizes, I found old taps and dies in my cupboard like M7, M2.5, M9, M11 and so on, just silly, the preferred sizes fixed that to a large extent but having fine and course pitches in the same size has caused me to resort to Helicoils on more than one occasion.

    Marl
    M2.5 is alive and well as far as I know. Widely available here, McMaster has them, and so do others. CAD programs have that as a choice.

    What's the problem with fine and coarse threads? Each has their place.

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  • MrFluffy
    replied
    Landrover was the king of mix and match until the freelander era. I had a range rover classic, and the front wings were held on by metric fasteners and the same area on the rear by imperial threaded fasteners but with metric sized hex's. When I was ordering new flexy hoses for the front, I had to go out with a pitch gauge and check them as the supplier couldnt tell by serial which it should be at which end. It ended up being a metric fitting one end and imperial at the calipers.
    I have a '89 landrover 90 now (precursor to the defender) and that has metric and imperial fasteners mixed on the swivel hubs which you cant change (ie if you change the swivel housings to metric you have to replace your brake calipers with metric ones too), and mostly metric elsewhere with the odd fastener lying in wait for the unwary (9/16th propshaft bolts etc). Makes buying replacement fasteners and sorting stripped threads out fun...

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  • whateg01
    replied
    Originally posted by boslab View Post
    ...
    But notably Metric tried to shoot itself in the foot when starting like specifying metric threads in a whole range of sizes, I found old taps and dies in my cupboard like M7, M2.5, M9, M11 and so on, just silly, the preferred sizes fixed that to a large extent but having fine and course pitches in the same size has caused me to resort to Helicoils on more than one occasion.
    Keeps you on your toes I suppose!
    Marl
    I have run across M9 threads on a bicycle axle recently. And some equipment that I used to maintain at work used M2.5 screws, and a lot of them, on RF enclosures. Not that bad to work with, but sometimes hard to source in the right length and head.

    I have been known to mix imperial and metric on occasion. Sometimes an imperial thread is too big for the space and the next one down is too small for the load. There is often a metric screw that is right in the middle and works great. I do try not to do that, but it happens.

    Dave

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  • boslab
    replied
    I spent most of Sunday fixing an assortment of problems on a US manufactured Case 1845c uniloader, after removal of about 2 barrow loads of manure/broken glass from inside the chassis I figure its history was recycling facility the dairy farm, anyhow I digress, the control linkages were totally sloppy so I figured it was due a service, what I found was a whole can of worms, imperial, metric in both fasteners and materials, loads of different hydraulic threads NP, Din, BSP, hours spent rummaging for taps like 1/4 x 28 NF 2 assorted pitches of metric, I wouldn't have been surprised if I had found LH British Standard Bicycle, as it was I did find a LH 1/4 UNF on a turnbuckle, however I'm not sure that was original or an old fence wire strainer that had been repurposed at some point in the throttle linkage ( actually for a solid rod linkage it's a fairly neat fix as you don't have to fiddle with tiny ball couplings at the ends)
    I don't see a problem in mixing but if in this day and age a method of identification of either metric or imperial could be devised it would make life easier, like the notch on fuel gas nuts, maybe something like that.
    I was fortunate that I had bought a blue point tap and die set at a flea market, I must say I do like the die stocks centering system, just rotate the cam plate to snug up the three jaws and your bang on.
    But notably Metric tried to shoot itself in the foot when starting like specifying metric threads in a whole range of sizes, I found old taps and dies in my cupboard like M7, M2.5, M9, M11 and so on, just silly, the preferred sizes fixed that to a large extent but having fine and course pitches in the same size has caused me to resort to Helicoils on more than one occasion.
    Keeps you on your toes I suppose!
    Marl

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  • J Tiers
    replied
    Making the set of tap drivers for english threads, I thought I would try the metric taps.

    being that most of the metric taps are US made, the shanks and driving squares all fit, so that the set of drivers for english threads also fits the metric taps up through 10 mm.

    I suspect that in Germany that might not be the case, but with the example of the 6,35mm driving squares for socket wrenches, who knows?

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  • Paul Alciatore
    replied
    Weston,

    Apparently you are not alone in this. I am replacing the operational handles and grips on the drill press I recently purchased and found that the factory items are a complete assortment of English and metric designs. One may be 3/8-16 and the next M8 or M10. You can not take anything for granted.

    http://bbs.homeshopmachinist.net/thr...ht=drill+press

    The Chinese have no hesitation in mixing dimensions. As to exactly how acceptable this is, I can not say. I have made things for my own use that mixed dimensions and found that they do work. I hate it more when someone mixes slotted and Phillips head screws on something.



    Originally posted by Weston Bye View Post
    I am in somewhat of a quandary here. Doing an article where I will be making details to bolt onto a machine made with metric fasteners and obvious round number metric dimensions. (bolt spacing & such). The same machine has hand wheels calibrated in inch. The metal stock for the bolt-on details will be mostly full dimension inch material. The fasteners not attached to the original machine are already specified inch.

    What a mish-mash to dimension.

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  • TGTool
    replied
    I had a foreman at one time with a sense of humor. He came around one evening with a string around one finger and said, "You know what that is?"

    I didn't.

    "That's a Polish hand calculator - with memory. If I have to, it can count up to twenty-one."

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  • Paul Alciatore
    replied
    Originally posted by rohart View Post
    Forest - if we'd developed with six finders on each hand, the world would have been a better place, I agree. ...<snip>...
    Just be glad we do not have one hand with seven fingers. Can you imagine: 7, 49, 343, 2401, 16807, ... I will take 2, 8, 10, 12, 16, or even 20 over that.

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  • lazlo
    replied
    Originally posted by The Artful Bodger View Post
    The difference is Lazlo that the Exe Engineering version has two datum surfaces so work can be held perpendicular to the surface (as on a lathe face plate) or parallel to the surface as on a milling table.

    The movable jaw can be flipped over to hold large or small stock.
    Ah, very interesting! So couldn't you do the same setups with a V-block bolted onto a shop-made baseplate? You'd have to have tapped holes in the side of the V-block, but a lot of them do, or you could tap a cast iron V-Block?

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  • TGTool
    replied
    Originally posted by lazlo View Post
    In the picture I posted, the movable "jaw" is on backward.
    There's a backwards? I always presumed it was made to go on either way depending on the size of the stock it was holding.

    The picture of the ad for the Keats block is certainly interesting. I see the prospect of vertical or horizontal mounting. OTOH, there are several small design features that seem problematic. The clamp now requires that U-bolt arrangement. There's a through hole for long stock but the hole doesn't seem to line up with the V-block unless the illustrator they hired to draw it only half understood what he was being told. The blind end of the V-block presents some manufacturing problems - not insurmountable, but then not as easily machined as the more recent incarnation.

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  • Weston Bye
    replied
    I am in somewhat of a quandary here. Doing an article where I will be making details to bolt onto a machine made with metric fasteners and obvious round number metric dimensions. (bolt spacing & such). The same machine has hand wheels calibrated in inch. The metal stock for the bolt-on details will be mostly full dimension inch material. The fasteners not attached to the original machine are already specified inch.

    What a mish-mash to dimension.

    Leave a comment:


  • The Artful Bodger
    replied
    The difference is Lazlo that the Exe Engineering version has two datum surfaces so work can be held perpendicular to the surface (as on a lathe face plate) or parallel to the surface as on a milling table. Someone told me that Exe Engineering that the intellectual property rights over the original design.

    Here is an original Keats advertisement


    Keats add by xxxx, on Flickr
    ..showing one the same pattern as the Exe Engineering ones.

    The movable jaw can be flipped over to hold large or small stock.
    Last edited by The Artful Bodger; 05-05-2013, 09:24 PM.

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  • whateg01
    replied
    This thread reminds me a bit of the conversion to metric of all of the automotive stuff. Looking for aftermarket wheels for a car a few years ago and I couldn't find new wheels that would fit my car. Gone were bolt circles of 5x4-1/2". Now we have 5x114.3mm. Took me a bit to realize that, but once I did, the world made sense again.

    Dave

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