Follower with rotating and translating movement

sarah_martinez903

I am working on an automata project so that I can show students how to animate their projects. I have most things figured out, but I cannot seem to get a follower to both rotate and translate up and down with the follower. I know I need to do a gear relation, but that only relates the revolute of the follower and the axle of the main rod. I am looking to get the follower to follow along with the path of the cam and rotate, but anytime I try to do both things, my assembly breaks.

Here is the link, hopefully it works.
https://cad.onshape.com/documents/a7c1c1ab9dc6774e1d2994f6/w/ddd5d521065e30612d8be670/e/23cc3e415c13e911f4ad2eb0Thanks

steve_shubin

@sarah_martinez903

SEE BELOW

steve_shubin

@sarah_martinez903

https://cad.onshape.com/documents/8ddad83224c365f84606959b/w/92ebd1cffee14ecc2d8410e1/e/c8939d27d61b6e73b5f7a44a

OK this one is working where every part is moving the way it should

in my previous post up above, that model was using a bit of trickery to get it to work. The vertical shaft was actually not rotating

But in this model, you can see that I added a little extra part that is FASTENED to the vertical shaft and that’s an indicator showing that that shaft is also moving in a rotational motion

I had to add an extra part to get it to do what it’s doing. The part is hidden

You have to manually crank that horizontal shaft to get everything to move

steve_shubin

@sarah_martinez903



This is a finicky set up here. The assembly can go batty

but the GIF herein shows a fix

You just have to rotate the vertical shaft a little bit to reset it

As far as the tangent mate, I think it’s gonna just operate in the red. If it really falls out I can use my iPhone to reset that tangent mate

I don’t know how to reset the tangent mate when using the desktop

you may have to reset the tangent mate  and then immediately afterwards rotate the vertical shaft a little bit to get it to work

@john_mcclary is the expert on mates. Maybe he knows a better solution

john_mcclary

When tanget mates start going funcky like that, try to replace them with relations instead.

john_mcclary

The rack and pinion relations weren't working the way I thought.
I ended up making a surface that is tangent to the ball of the rod instead.
It's a bit more controllable but it is still a tangent mate, so there is always a chance for it flipping inside out.
Axle v.SS2 - Copy | Assembly 1 (onshape.com)

steve_shubin

@john_mcclary

Had to call in the expert to get the job done right

The good thing is — is I get a document to learn from — which I always like

steve_shubin

@john_mcclary

I just opened up your document. What a great solution.

A lot simpler than what I was thinking  I would have to go through to use a relation

just a simple extruded circle

Genius

john_mcclary

would be better to have a sketch with a single point to be tangent to the sketch rather than the rounded tip of the rod. Since a point on a curve is better than two curves

sarah_martinez903

Thanks for all the help. The modifications are helpful for students to see the motion they want. That will be a good workaround. I was hoping to get it in the orientation I had it, so it can show the direct movement of what will be happening in their actual device, but if there isn't that sort of solution, the workaround will let them see the motion at least, even if it doesn't directly match up to what they will be doing. @john_mcclary @steve_shubin

steve_shubin

@sarah_martinez903

Hi Sarah

You mentioned orientation

These automatas are new to me. Sorry for the mess up on that orientation

I found this on YouTube this morning.   Automata - YouTube

I’m guessing you want the orientation to be as with the automata seen at the very start of this video — the one shown between 0 and  the 18 second mark.

In the case of this one, the wheel attached to the vertical shaft is sitting ON TOP of the cam

is this what you were looking for?

Here is the updated document

https://cad.onshape.com/documents/8ddad83224c365f84606959b/w/92ebd1cffee14ecc2d8410e1/e/c8939d27d61b6e73b5f7a44a

sarah_martinez903

Yes, that's what I was trying to get