# Joints / Linkage

**URL:** <https://discourse.shapr3d.com/t/joints-linkage/29788>\
**Category:** Modeling Questions\
**Created:** [January 9, 2024, 9:54pm UTC](https://discourse.shapr3d.com/t/joints-linkage/29788 "2024-01-09T21:54:28Z")\
**Posts on this page:** 8\
**Page:** 1

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**Author:** ![boostjuice](https://avatars.discourse-cdn.com/v4/letter/b/e56c9b/32.png) [@boostjuice](https://discourse.shapr3d.com/u/boostjuice)\
**Post date:** [January 9, 2024, 9:54pm UTC](https://discourse.shapr3d.com/t/joints-linkage/29788/1 "2024-01-09T21:54:29Z")

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I am very new to Shpr3d and absolutely love it so far!

I am working on designing a shifter assembly for a motorcycle engine into a car (push/pull to shift). I have the bodies created and aligned, however I am lost when trying to test function.

I understand the rotate-on-axis function, but cannot seem to figure out how to rotate a linkage on 4 points.

Any help is very much appreciated!

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**Author:** ![FWP](https://avatars.discourse-cdn.com/v4/letter/f/a587f6/32.png) [@FWP](https://discourse.shapr3d.com/u/FWP)\
**Post date:** [January 9, 2024, 11:48pm UTC](https://discourse.shapr3d.com/t/joints-linkage/29788/2 "2024-01-09T23:48:48Z")

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To my knowledge you can only rotate on a single axis at a time in shapr. However I am pretty sure you can export the bodies into a free program like blender and then perform that function without having to pay for an expensive subscription to fusion etc.

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**Author:** ![McD](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/mcd/32/15504_2.png) [@McD](https://discourse.shapr3d.com/u/McD)\
**Post date:** [January 10, 2024, 12:07am UTC](https://discourse.shapr3d.com/t/joints-linkage/29788/3 "2024-01-10T00:07:38Z")

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Currently, the best one can do is to select multiple bodies, move the rotation point to the pivot location, then rotate the selected bodies. There are no kinematic functions in Shapr3D. I sometimes move bodies, one after another, then screen record while reversing steps. This results in a pseudo 4 bar linkage scenario, but only in one plane.

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**Author:** ![Bob3DPO](https://avatars.discourse-cdn.com/v4/letter/b/7993a0/32.png) [@Bob3DPO](https://discourse.shapr3d.com/u/Bob3DPO)\
**Post date:** [January 10, 2024, 1:55am UTC](https://discourse.shapr3d.com/t/joints-linkage/29788/4 "2024-01-10T01:55:37Z")

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Hi Ryan,

Gregg Johnson @GJetson did a nice piece about four point linkage in sketches that might be useful.

> [@Kinematic linkage simulator](https://discourse.shapr3d.com/t/kinematic-linkage-simulator/8666/10):
>
> Here’s the link to the video. It’s thrown together very quickly and the audio is far from ideal, but it covers some important details for any user who is new to this process, so it’s good enough for now.  
> (Note that it’s published at 1024 HD but users might have to select that higher resolution, because when I tried the link here, the default resolution was 320.)
> 
> [https://youtu.be/st56mMLOans](https://youtu.be/st56mMLOans)

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<div class="post-metadata">

**Author:** ![McD](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/mcd/32/15504_2.png) [@McD](https://discourse.shapr3d.com/u/McD)\
**Post date:** [January 10, 2024, 2:22am UTC](https://discourse.shapr3d.com/t/joints-linkage/29788/5 "2024-01-10T02:22:19Z")

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Bob, interesting find. Thank you for sharing this. I will have to try this.

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<div class="post-metadata">

**Author:** ![boostjuice](https://avatars.discourse-cdn.com/v4/letter/b/e56c9b/32.png) [@boostjuice](https://discourse.shapr3d.com/u/boostjuice)\
**Post date:** [January 10, 2024, 6:16am UTC](https://discourse.shapr3d.com/t/joints-linkage/29788/6 "2024-01-10T06:16:57Z")

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Thank you all! Good suggestions here, thanks!

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**Author:** ![jcclow](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/jcclow/32/23888_2.png) [@jcclow](https://discourse.shapr3d.com/u/jcclow)\
**Post date:** [January 10, 2024, 11:50pm UTC](https://discourse.shapr3d.com/t/joints-linkage/29788/7 "2024-01-10T23:50:12Z")

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You beat me posting that link Bob 😀

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**Author:** ![NathanD](https://avatars.discourse-cdn.com/v4/letter/n/dec6dc/32.png) [@NathanD](https://discourse.shapr3d.com/u/NathanD)\
**Post date:** [January 11, 2024, 5:38pm UTC](https://discourse.shapr3d.com/t/joints-linkage/29788/8 "2024-01-11T17:38:02Z")

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Using HBPM, and a base sketch with the constrained movements like in the video, you can build your model “joints” off the base sketch.

So in other words, you can do pretty much the same thing as the video, but with the bodies as well.

It has some limitations, as the “joint” movement is only 2D, or limited to how a sketch can move, and there’s no contact limits if modeled parts collide. It can also get tricky to model, because everything has to be built to be driven from the base sketch. And the movement is not very fluid, because it’s relying on Shapr to rebuild the model every time the base sketch is adjusted, which can get slow depending on your history tree features…

BUT IT WORKS 👍🏻

I was able to simulate a motorcycle springer fork’s movement and adjust geometry to see what would be the best way to make some parts.