3D Printable Kinematic Couplings, Ready To Use

Time may bring change, but kinematic couplings don’t. This handy kinematic couplings resource by [nickw] was for a design contest a few years ago, but what’s great is that it includes ready-to-use models intended for 3D printing, complete with a bill of materials (and McMaster-Carr part numbers) for hardware. The short document is well written and illustrated with assembly diagrams and concise, practical theory. The accompanying 3D models are ready to be copied and pasted anywhere one might find them useful.

What are kinematic couplings? They are a way to ensure that two parts physically connect, detach, and re-connect in a precise and repeatable way. The download has ready-to-use designs for both a Kelvin and Maxwell system kinematic coupling, and a more advanced design for an optomechanical mount like one would find in a laser system.

The download from Pinshape requires a free account, but the models and document are licensed under CC – Attribution and ready to use in designs (so long as the attribution part of the license is satisfied, of course.) Embedded below is a short video demonstrating the coupling using the Maxwell system. The Kelvin system is similar.

In the past we saw the Maxwell system form the basis of this 3D-printed magnetic camera mount. Want a more in-depth resource for kinematic couplings? Check out [Joshua Vasquez]’s take on the book Exact Constraint: Machine Design Using Kinematic Principles.

11 thoughts on “3D Printable Kinematic Couplings, Ready To Use

  1. Nice, but this is not really a kinematic coupling: there are three equivalent slots, whereas the exact kinematic coupling supposes under each ball respectively a cone, a slot directed towards the cone, and a plane.
    The exact kinematic coupling is simpler to realize, much more tolerant to realization imperfections, and indifferent to dilatations: why deprive ourselves of it?

  2. You have to “sign up” to download the design files. I could upload a nice animation and design files illustrating my opinion of that . . . Pick a host that doesn’t require an account to download.

  3. Yowsa. For the cost of that McM-C BOM to make three plastic kinematic couplings I can just about buy three real metal kinematic couplings and the mirrors that go in them and the whole frickin’ K40 laser cutter to go with them.

    1. It looks like you really only need 6 magnets and 3 BBs for each, not sure what the other stuff on the BOM is for. I think there might be some other designs. Magnets are $1 each and BBs are $12 for a pack of 100.

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