How would someone model the yellow part as seen in this vid?

[AWESAM22]

In the comments the guy says to "Make many copies the red part and use Cavity", but I have tested that out and haven't had any success. More specifically, I've tried:

1. making a cylinder and mating the outer face tangent to one of the red part's faces + adding other mates so each part is oriented properly.
2. using circular pattern to add the red parts all the way around
3. using cavity feature with all of the red pieces to make the yellow piece

Unfortunately, I have not found a combo that works using this procedure. I know that the red part is made by using revolving a sketch of the face of a gear. However, this one has me stumped. Is there perhaps something with motion study that can be used to create a series of cavities from the rotating motion shown in the video? Any help is appreciated. Feel free to DM me if you have more questions or if you would like me to send you a model of the red part so you can give this a try.

 

[JPARKER]

What version of SWX are you running?

I believe the make copies would work, but you would need the red part to be modeled first and then a sketch point at the tangency of each curve on the red part to align with the rotation of the yellow and then us Cavity to subtract the red from the yellow.

I am going to see if there is a better way either by layout or equation to create the curves on the yellow part to follow.