Controlling mechanism with slider and revolute joints

[Anonymous]

Good afternoon,

I'm just getting started with Fusion 360. I'm trying to create a model with a few joints and can't get the slider joint to work as desired.

In the screen capture below, the blue vertical rectangle on the right side is grounded and intended to remain stationary. The gray rectangle near the bottom of the mechanism is connected to the blue vertical rectangle with a revolute joint. My intent is to allow the gray bar to rotate.

The two light brown / tan vertical rectangles near the left side of the mechanism should be connected to the gray rectangle located along the bottom. These two rectangles are intended to move up and down. This is the motion and joints I haven't figured out.

The short gray rectangle near the top of the mechanism is grounded and connected to the two vertical rectangles with two slider joints; one for each vertical rectangle. This is intended to constraint the two vertical rectangles to near-vertical movement.

If I animate the joints individually, I get the desired  behavior from each joint. I can't move the two vertical rectangles by moving the longer gray rectangle. This is the problem I'm trying to work through. Any suggestions?

Update: since I made the screen capture, the icon for the slider joint on the left tan rectangle has been corrected. It now matches the upward pointing arrow found on the right tan rectangle.

[jhackney1972]

It would really help, get an accurate and relative answer, if the forum users had your model.  Please attach it.  If you do not know how to attach your Fusion 360 follow these easy steps. Open the model in Fusion 360, select the File menu, then Export and save to your hard drive. Then use the Attachments section of a forum post to attach it.

[jhackney1972]

Do you need further help in attaching your model to a forum post?  Your question can probably be quickly solved if we had your model.

[davebYYPCU]

Sliding vertical bars must rotate to keep their lower pins connected, to the gray swing arm,

if the gray swing arm is slotted would work.

Think, Piston, Piston pin, Conrod, Crank, you don’t have the Piston pin function anywhere, so it locks up.

Might help....

[Anonymous]

Sorry for the delay in responding. The weather here has been beautiful and my dog needed a hike. The model is attached to this post.

Thanks,

Scott

[davebYYPCU · Accepted solution]

See what I mean?

Might help....

[Anonymous]

I see it but I'm going to play around with this for a bit. I'm getting some unexpected behavior that might just require me to read some more or watch a video or two. Thanks!

[Anonymous]

Thanks for the help. As I suspected, I needed to dig a little deeper into the pin slot joint and figure out what I was doing wrong / why it wasn't working. Everything is working now.

Thanks,

Scott

[jhackney1972]

Here is your model with the construction and joints I think you desire.  Pin and Slot joint "PinSlot20" is limited to make the mode stop a the maximum stroke.  You have a lot of yellow in your timeline you need to sort out.

[Anonymous]

Thanks, John! That's basically what I ended up doing but my solution is a "less refined" variation as yours. I created a single rectangular slot without the filleted ends and I didn't work through the math to get the dimensions dialed in. It works but definitely needs some cleanup.

While figuring out Fusion 360, I ran across a few YouTube videos you created. Good stuff; straight to the topic and proper length for my attention span.

Scott