A 100% 3D Printed Linear Snap Action Mechanism.

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Introduction: A 100% 3D Printed Linear Snap Action Mechanism.

About: Our grandkids keep me busy!

Sometimes you look at a mechanism such as "A 100% 3D Printed Linear Snap Action Mechanism" and wonder what could this be useful for? Well, mechanical snap action mechanisms have a number of uses including toggle switches and numerous process control applications.

To illustrate the use of mechanisms such as this, along with the included design and assembly video, I've included a second video of how I used this mechanism to provide mechanical reversing in an automaton design of mine. I designed this mechanism to provide linear mechanical hysteresis for the automaton, and published a video of the prototype model on YouTube, whereupon which a number of educators messaged and commented that they would like to be able to recreate this mechanism in their classrooms, so here is the snap action model in an easy to 3D print cutaway form.

As mentioned, the design and assembly process for this mechanism is illustrated in the first video, and I've included the Autodesk Fusion 360 file "Snap Action, Linear.f3d" for those interested in editing the design. I 3D printed all parts at .15mm layer height with 20% infill.

As usual I probably forgot a file or two or who knows what else, so if you have any questions, please do not hesitate to comment as I do make plenty of mistakes.

Designed using Autodesk Fusion 360, sliced using Ultimaker Cura 4.7.0, and 3D printed in PLA on Ultimaker S5s.

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    22 Comments

    0
    fritz7705
    fritz7705

    Question 10 months ago

    Is it possible to get the correct files for the spring and slide ?

    0
    Penolopy Bulnick
    Penolopy Bulnick

    Answer 10 months ago

    Can you please post a screenshot of what you are seeing? Of how the images are not matching up to what the file says it is?

    0
    fritz7705
    fritz7705

    Reply 10 months ago

    Here you go!

    Screenshot (6).pngScreenshot (8).png
    0
    gzumwalt
    gzumwalt

    Answer 10 months ago

    Hi fritz7705,

    The files are correct (download them into your slicer, you will see), the images provided by Instructables.com are not correct. Sorry for the confusion, hopefully Instructables will correct this error.

    Greg

    0
    AlexanderS290
    AlexanderS290

    10 months ago

    i feel like you uploaded a different spring - its a spiral one instead of a pair of blades.

    0
    Penolopy Bulnick
    Penolopy Bulnick

    Reply 10 months ago

    Can you please share a screenshot of what you see for the documents on the Instructrable?

    0
    gzumwalt
    gzumwalt

    Reply 10 months ago

    Hi Penolopy,

    It’s the last two images, the spring and the slide, which are incorrect. Downloading the file and viewing them with a .stl viewer shows the correct image.

    This is prevalent on a number of my models.

    Greg

    E0759837-CBE8-4512-B54A-0F7EF5807A31.png
    0
    Penolopy Bulnick
    Penolopy Bulnick

    Reply 10 months ago

    Thank you, of course I downloaded the first two STLs and saw they were right and assumed the other two were right based on the names :P sorry about that, I should have downloaded them too, that was lazy of me.

    Anyway, this was reported a while ago by one person for a single file but I was unable to reproduce or find any other examples and now that I have this one too I have reported it. If you have any others with the same issue (or have witnessed it with other people's projects), please let me know so I have more examples to bring to the team!

    0
    AlexanderS290
    AlexanderS290

    Reply 10 months ago

    the preview shows a black circular spring (as other image uploads below show as well) but when opening the STL file in cura it shows the right item.

    there is indication that some (or most?) STL files will have a built in preview image.
    thus it might be the case that an outdated image is in the given STL - i need to check with some local thumbnail viewer, e.g. an extension to the MS file explorer view.
    http://community.robo3d.com/index.php?threads/how-to-get-stl-thumbnail-view-using-windows-explorer.7596/#:~:text=Standard%20windows%20explorer%20doesn't,the%20STL%20as%20an%20image.

    spring-flat.png
    0
    gzumwalt
    gzumwalt

    Reply 10 months ago

    Hi AlexanderS290,

    No, the springs are correct, it's Instructables. Sometimes they assign the wrong (older) images to new uploads.

    But thanks for pointing that out!

    Greg

    0
    Penolopy Bulnick
    Penolopy Bulnick

    11 months ago

    That's a neat little mechanism :)

    0
    Penolopy Bulnick
    Penolopy Bulnick

    Reply 10 months ago

    That's really neat to see! Thanks for sharing the video :)

    0
    gzumwalt
    gzumwalt

    Reply 10 months ago

    Hi Penolpy,

    You are welcome!

    I have had more than a few people complain to me that the images appearing in the download section do not appear correct, yet the downloads are indeed correct, its just that the images in the download section do not pertain to this Instructable I've had issues with this in a few of my previous Instructables where the downloads are correct, but the images of the downloads are not correct.

    Just an FYI to fix.

    Thanks again!

    Greg

    0
    Penolopy Bulnick
    Penolopy Bulnick

    Reply 10 months ago

    Do the images appear correctly to you? They seem to be correct for me. It could be people need to clear their cache, otherwise I'm not sure why they would see the wrong images when we see the right ones.

    Screen Shot 2020-12-10 at 7.14.19 AM.png
    0
    VinayDand
    VinayDand

    10 months ago

    Excellent concept,
    Nice use case demo.
    Will use this in future design
    Thanks for sharing and superb engineering

    0
    gzumwalt
    gzumwalt

    Reply 10 months ago

    Thank you so very much, I'm glad you enjoyed it!

    Greg

    0
    AlexanderS290
    AlexanderS290

    10 months ago

    nicely made.
    i first felt like its the new successor for the fidget spinner.
    but now i found out it has more practical use than i assumed.
    with a little more of works (like scaling and alikes) it can be turned to fit into a bunch of solutions - e.g. a box (trick) lock.

    0
    gzumwalt
    gzumwalt

    Reply 10 months ago

    Thank you AlexanderS290, I'm glad you enjoyed it!

    I designed this mechanism for use in a prototype snake automaton (video is above). It provides mechanical hysteresis for a mechanical reversing mechanism.

    Greg