Problem on ratchet gear

[Anonymous]

How should i create a sketch for ratchet gear, since i only can add in spur gear in fusion 360.

And what should be used as the joint mode when i want the pin toslide off to the next teeth of the gear?

Thanks

[paul.clauss · Accepted solution]

Hi @Anonymous,

Welcome to the Fusion 360 Community! Thank you for posting!

It looks like you have some questions about modeling a ratchet gear and then creating joints to accurately represent the motion of a ratchet. 

To begin, it is unfortunate that Fusion 360 does not have an add-in that can accurately create ratchet gears. You can, however, sketch your own without too much difficulty. I like to use a some construction geometry and a circular pattern. I've attached a screencast illustrating how I would approach the sketch for one of these gears below. 

After creating the gear, we still need to set up the joints to accurately portray the motion of the gear. To do this, I used two revolute joints and enabled contact sets. I then noted the maximum rotation of the ratchet arm, and applied a joint limit and resting position to it. The screencast below shows this process. I forgot to mention it when recording the screencast, but you must select the "Enable Contact Sets" option under the Assemble ribbon for this technique to work. 

Hopefully this helps you get started with your own model! Feel free to let me know if you have any other questions - I'm happy to help!

Thanks,