Mechanical Rigging - Two Arms

[erik.markstaedter99]

Hello there,

Last night I met this problem. I wanted to connect/link two rotation Tubes with a door. So that if I move the door the things would rotate, but I have no idea how to do it and I also looked up everywhere but couldn't find anything. Thanks in advance if you have an explanation or any link to other post or video!

[ads_royje]

Hi @erik.markstaedter99,

a tool to do such a setup would be to use Wire Parameters

http://help.autodesk.com/view/3DSMAX/2019/ENU/?guid=GUID-B084D14B-2925-4EA6-890F-4F2564BB9D9A

Wire Parameters can link different parameters together, so modifying one would modify another (or more).

[leeminardi]

It is a bit difficult to determine from the picture the exact behavior you expect from the mechanism.  As I read it the pivots for the links A and B are fixed and the door pivots about a point below the picture.  Yes?  Does the link coming from A extend?  If so a LookAt constraint might work. The linkage at B looks like a standard 4-bar linkage which can be easily rigged with an HI IK Solver. 

Please provide more detailed info about the linkage, or better yet a file, and I can provide more details about how to rig it.

[erik.markstaedter99]

What you replied is what I actually imagined. I will give LookAt Constraints a go. Here's the file anyway and also two pictures of before and after (done without rigging) how the door is supposed to move

File: https://mega.nz/#!USQmBQwB!7hdYqerTF-FMPUeLuyb6MfeiVRAnq3brd59vP3CG83M

[erik.markstaedter99]

Thanks for the reply! I tried this method, but I can't select multiple positions axis (This case: X & Y Axis) for a single rotation axis (Z in this case). I posted the file below. Take a look if it is more helpful

[leeminardi · Accepted solution]

I've rigged the right side door as follows:

Select and rotate Doors_Big and you will see the linkage at the top articulate as it should. Rotating Object15 repositions the pivot point of Doors_Big and the rest of the links move accordingly.

I had to reposition the pivot points of Doors_Big, Object15, Object22, and object23 so that they we in a proper place for a linkage.  I also removed the Wire Parameters.  I recommend using a logical naming scheme for all your model components. The top links form a 4-bar linkage (door, the 2 links, and ground). The bottom link simply repositions the door.

To see how to model a 4-bar linkage check out this video I created some time ago.  The action of the bucket is similar to the 4-bar linkage you have at the top of the door.  Note, it isn't necessary to use bones.