Making a Cam joint work

[Anonymous]

Easy question I think:

Here is a link to my file: http://a360.co/2o5TLfV
I am following this tutorial: https://www.youtube.com/watch?v=2ZB63JMUcVM


So anyways, the contact set appears to work... somewhat, I can spin the joint a little and the cam actuates the arm correctly, but once the cam rotates a bit, the pin falls "into" the cam and no longer interacts with it, afterwards the cam refuses to move at all unless I disable the contact set, im guessing this has something to do with the cam itself

Am I doing this right? Does fusion360 have an issue with contact sets across arcs?  is there a better way of making a cam profile?

[TrippyLighting]

CAM joints are a specific weakness of Fuion 360 and unfortunately we are still missing a joint or motion link that would allow us to do a CAM joint easily.

Contact sets are a poor way to replace a proper joint.

In the 2 1/2 half years I've worked with Fusion 360 and in the time I've spent here on the Forum I' ve seen vastly more problems with contact sets than solutions.

Forget using a contact set even in a moderatly complex assembly!

[Anonymous]

Hm, well thats not promising

Is there a better workaround for this? maybe making a cam with a "slot" for the pin to ride in and somehow telling it to follow the slot or something?

I'm new to joints 🙂

[TrippyLighting]

Let me clarify.

You can probably complete this tutorial succssfully as the assembly is really simple and only a couple o other joints are involved. If you can share the desing you have so far I can take a look at it later (I am not near my Fusion station at the moment).

However, contact sets really have very limited practical application in real assemblies.

Aside from these limitations, the joint system in Fusion 360 works very well, but can require a bit of-re-learning if a user has exparience with other CAD systems, e.g. Solid Works.

[Anonymous]

No prob, the link to my file is in the first post

it'll be sort of complicated eventually though, it'll be a 4 bar mechanism actuated by a cam

[mufadal89]

Instead of using contact set . there should be a tool in Fusion which generates a Equation correlating angular position of input shaft to linear motion of the follower in various types of motions. If this is there then you would not have to rely on contact sets. 

Just like a motion link but instead of rotation to rotation it would be rotation to translation governed by equations.

[TrippyLighting]

The first joint in your assembly between theCam and the Drive Shaft should be a rigid joint, not a revolute joint. If you change that it'll work.

I name almost all joints when I make assemblies with the components/assemblies they are joining. That makes debugging much easier.