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Bolt and Nut Full Tutorial?

4DeltaEDU4DeltaEDU OS Professional Posts: 15 PRO
edited January 2017 in Community Support
Is it possible to have uploaded here a full tutorial (either in the form of a Video or instructions) with a step by step procedure and dimensions on how to successfully create a thread matched Bolt and Nut Assembly with a screw relation?
Every time I am attempting to create one the threads never seam to match and the screw relation never works. Has anyone here managed to create a successful screw relation between a bolt and a nut? 


Answers

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    philip_thomasphilip_thomas Member, Moderator, Onshape Employees, Developers Posts: 1,381
    Lots going on here - i hope that some of this helps

    There is a quick tutorial on how to build a nut with threads
    https://www.onshape.com/cad-blog/tech-tip-creating-a-thread

    Threads are challenging because internal threads are different from external threads.
    Some companies have build taps (with female threads) and dies (with male threads) that they derive into a part studio and then position (transform) by mate connectors and then do a boolean subtract. (Note if you go this route - please export your parametric taps/dies as parasolid and then import into your standard threads document - this improves performance significantly).

    The example i have made for you does NOT use this method and there is NO difference between the male and female threads (my ADD would have kicked in way before i finished - had I tried to do that and you would have got nothing :))

    The next 'trick' is when assembling your nuts/bolts is that there is a difference between the centroid of both the parts and the center of the faces. This is due to the nature of a thread that has a start and end. You want the center of the face of the underside of the bolt and the center of the flat face of the nut (in other words, the mate connection point that is NOT the centroid symbol). To help you - remember to use the SHIFT key to free the mate connection points.




    Remember to use a CYLINDRICAL mate (two degrees of freedom)



    Next - you are going to use the SCREW mate relation. It's a special case of mate relation that takes as input only a single mate (all the other ate relations take two mates as input.

    That's it! You could optionally add limit mates, but you get the idea.

    https://cad.onshape.com/documents/586ea13479772510f11bea2e/w/b6756361631ed4ad1a3277be/e/caa1725846e5fc4a6ed2798a

    I hope this help you - Philip . . . 
    Philip Thomas - Onshape
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    4DeltaEDU4DeltaEDU OS Professional Posts: 15 PRO
    Hi Phillip thanks for your feedback.

    Unfortunately there is a very very tiny gap between my thread design due to the ISO standards I used. In reality there's always a very tiny gap. According to Tim Rice who is also trying to help me out is the main reason why I cannot achieve the screw mating. He suggested that I can certainly still achieve my design intent, though it may be slightly more difficult. Using the section view tool, l have to manually add mate connectors along the bolt's axis such that the bolt and nut threads are aligned when the mate connectors are coincident. I have to determine the correct linear distance traveled per rotation for the screw relation. I have made several attempts but without luck. Any words of wisdom? I am trying to get this solved for a tutorial I am teaching.

    Thank you for taking the time 
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    philip_thomasphilip_thomas Member, Moderator, Onshape Employees, Developers Posts: 1,381
    @4DeltaEDU - send me an email (pthomas@onshape.com) with times that we could do a web meeting so that i might better understand what you are trying to do. I will help you - in exchange, you agree to post the solution here - deal? :)
    Philip Thomas - Onshape
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