pic: CGX-104 cycloidal versaplanetary external

[ajlapp]

Everyone of these units I've ever seen has either had multiple wobble plates out of phase for balancing or a dedicated balance weight.

There's no free lunch.

It's no coincidence that you only see these types of drives in major industrial applications where a bit of extra mass and volume is worth some of the cycloid's benefits.

Here's an unbalanced unit designed to work with RS-550 and RS-775 motors built for the 2012 FRC season.

You can see that this unit is very polished and was even intended for production...however, its promise didn't match with its performance.

https://www.dropbox.com/s/mthooimzm0...42.02.jpg?dl=0

[asid61]

Originally Posted by ajlapp

Everyone of these units I've ever seen has either had multiple wobble plates out of phase for balancing or a dedicated balance weight.

There's no free lunch.

It's no coincidence that you only see these types of drives in major industrial applications where a bit of extra mass and volume is worth some of the cycloid's benefits.

Here's an unbalanced unit designed to work with RS-550 and RS-775 motors built for the 2012 FRC season.

You can see that this unit is very polished and was even intended for production...however, its promise didn't match with its performance.

https://www.dropbox.com/s/mthooimzm0...42.02.jpg?dl=0

I was thinking of putting a second gear of the same mass 180* out of phase, but on the same shaft, such that I would basically be getting the face width of both of the cycloidal gears in strength. So essentially having multiple wobble plates, yes.

[ajlapp]

You must put the second and/or third plate must be on their own eccentricity that is also out of phase.

[akoscielski3]

I have to say, this looks like a fun engineering challenge, and good on you for designing this.

In regards for a team machining this though, I always try and recommend buying as many parts as possible (of course this depends on your team's budget however), rather then machining them. The reason is, you can put that much more time into either designing, programming, or practicing with your robot.

In the first few years that I was on 772, we machined a lot of our own parts. However, when I started to design the robots we transitioned to buying more COTS parts. We focused on designing more, rather then machining. And we were "done" the robot a week earlier then normal, and had a lot more practice with it. The robot's level of performance went way up too.

Remember, your robot isn't going to become a great competitor because you custom built a transmission, but you can get better by designing the whole robot better, having a great strategy, having reliable parts (with easy to find replacements), and having more practice.

[asid61]

Originally Posted by akoscielski3

I have to say, this looks like a fun engineering challenge, and good on you for designing this.

In regards for a team machining this though, I always try and recommend buying as many parts as possible (of course this depends on your team's budget however), rather then machining them. The reason is, you can put that much more time into either designing, programming, or practicing with your robot.

In the first few years that I was on 772, we machined a lot of our own parts. However, when I started to design the robots we transitioned to buying more COTS parts. We focused on designing more, rather then machining. And we were "done" the robot a week earlier then normal, and had a lot more practice with it. The robot's level of performance went way up too.

Remember, your robot isn't going to become a great competitor because you custom built a transmission, but you can get better by designing the whole robot better, having a great strategy, having reliable parts (with easy to find replacements), and having more practice.

While designing this, I made sure to make it such that each could be machined with only access to one side (with the exception of the output shaft, no flipping of parts is required). That being said, I more designed it as a "replacement" for a versaplanetary; hypothetically, if I had access to Vex's machining resources, how would I be able to use them to make a gearbox? The end result actually requires less machining in some ways, although I'm not 100% certain how they make the output shafts on the versaplanetaries.
I agree with you though, COTS parts and driver practice is magic. A few days with our robot between SVR and Champs doubled our potential score.