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Thread: Making small bolts

  1. #21
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    Quote Originally Posted by Paul Alciatore View Post
    A design that requires a thread right up to a shoulder is not a good design.
    kind of think you want to see the design and circumstance before passing judgment. The design for much model work is for appearance and carry next to zero load. There are many times where its all but unavoidable because what you are attaching is so thin.

    I usually thread them in the usual way, then reverse the die to get it closer to the head. I wouldn't hesitate to grind the side of the die down if that wasn't good enough, but use it like you would a bottoming tap, just for finishing it off.
    .

  2. #22
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    Another angle on it. You could make the screws as normal. Then finish them using a die plate (as used by watchmakers) that you have made possibly dishing the position of the die hole first so that it can really get up close to the screw head. As it would only be cutting the last half turn it will have less wear risk.

  3. #23
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    Quote Originally Posted by RB211 View Post
    If we are doing this as a hobby, out of love for it, I can't calculate my time as having a monetary value. If we did that, every model anybody ever made would be worth over 10,000$
    You should add another zero to that! Some of these models take years, even decades to produce and if you were to add up the man (or woman) hours at a minimal wage it could be a huge number.

    Quote Originally Posted by Baz View Post
    Another angle on it. You could make the screws as normal. Then finish them using a die plate (as used by watchmakers) that you have made possibly dishing the position of the die hole first so that it can really get up close to the screw head. As it would only be cutting the last half turn it will have less wear risk.
    I haven't much knowledge in watchmaking so I guess I will have to research die plates. Sort of a primitive threading die??? Thanks
    Last edited by loose nut; 08-27-2019 at 09:59 AM.
    The shortest distance between two points is a circle of infinite diameter.

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  4. #24
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    If I was into this I’d set up my CNC mill for threading using the 4th axis which can stop right up against the bolt head, and cut the hex in the same operation.

  5. #25
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    Turning the die around gives a clean thread to within roughly a bolt diameter or less of thread taper to the underside of the head. I'm thinking that the idea from an earlier post of simply drilling a short counter bore in the parts that are threaded for the screws/bolts would be an easier solution than to try for a thread that is cut all the way to the head. Or as mentioned as well just a bit of a chamfer in the threaded part to allow the head to sit close enough. It would not take much of a chamfer, particularly with a 60* countersink, for clearance of that last bolt diameter or less to let the shop made bolts fit closely enough.

    If you don't want the look of the chamfer then a short one bolt diameter counterbore could be done easily with a suitable drill in a hand drill and with a depth control sleeve over the drill bit. That's if you don't want to do it in the drill press or mill after the tapping size holes.

    And after all, when we look at commercial bolts that are threaded to the head they are actually not threaded right to the head. They all have roughly half a diameter or so of taper out and often a short untouched portion of shank.

  6. #26
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    Quote Originally Posted by loose nut View Post
    I have to make a lot of small bolts... My problem is that threading dies don't thread up to the base of the head...
    If threads are required up to the head, then, by definition, you are not making bolts. You are making setscrews.

  7. #27
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    Quote Originally Posted by RB211 View Post
    If we are doing this as a hobby, out of love for it, I can't calculate my time as having a monetary value. If we did that, every model anybody ever made would be worth over 10,000$
    I get that. Whatís the point in having thousands of dollars worth of machinery if you canít make $0.29 parts?! I do it frequently!
    Sole proprietor of Acme Buggy Whips Ltd.
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  8. #28
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    Quote Originally Posted by djc View Post
    If threads are required up to the head, then, by definition, you are not making bolts. You are making setscrews.
    Set screws don't have heads.
    The shortest distance between two points is a circle of infinite diameter.

    Bluewater Model Engineering Society at https://sites.google.com/site/bluewatermes/

  9. #29
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    Quote Originally Posted by Beazld View Post
    I get that. What’s the point in having thousands of dollars worth of machinery if you can’t make $0.29 parts?! I do it frequently!
    Yep. If we had to keep time, I'm pretty sure I've made some $100 precision washers.

  10. #30
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    I've ground dies down in the past and it does work well,only thing I don't like about it is all the threading and un-threading required,especially if it's a long thread.So I had the idea once to make a finishing die that opens and closes like a pair of pliers.Never did it,but it is on my list of roundtoits.

    Last edited by wierdscience; 08-27-2019 at 10:31 PM.
    I just need one more tool,just one!

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