What is the use for use cases for Planetary Gear , XL Turntable Pack and Turntable gears

It would be great to get some videos, exercises or pdfs for team to understand the use cases for these gears - Planetary Gear , XL Turntable Pack and Turntable gears


Planetary gears are easier than they appear. They basically allow you to have extreme gear ratios in a very compact area. I initially thought it was a transmission but over time I realized it was to change gear ratios on the same plane. You can see a planetary gearbox if you opened up the V5 VEX cartridges (or by googling planetary gearboxes).


What would be the most

gear ratio with the IQ planetary gear kit @vexiq2021user is talking about?

Hmm… I guess I even misinterpreted that. It appears to just have a gear ratio on a plane, but it depends on gear size (but since you’re limited with what you have I am pretty much certain the max gear ratio for planetary is around 6-8:1 from the kit, not sure though).


Outer gear is 36, inner gears are 12.

There is also a planetary on the solar system model (Orbit) that is 60 teeth, so 60:12 for it.

1 Like

That would be nice! Too bad it’s not in the planetary gear set.

So from what I can tell, standard gear boxes go (normally) up on the beam, whereas a planetary gear box could go straight on a shaft to save room for other components. Interesting!

If you look at the planetary gear set on the site, the last picture is a motor, beam, gear and beam to show how you can compress the needed gear space. You are most likely findin as you builds increase in complexity that space (both breadth and thickness) starts becoming a design issue.


Based on the planetary kit using a 12 tooth sun gear, 12 tooth planet gears and a 36 tooth ring gear, you have all sorts of options. There is a planetary gear calculator / demonstrator at http://www.thecatalystis.com/gears/. You need the following parameters to model the VEX IQ set:

  • 4 planets
  • 12 sun teeth
  • 12 planet teeth
  • 36 ring teeth

Plug in a few values and look at the results. You can achieve a 4:1 or 3:1 reduction pretty easily in a very compact location with a quite robust mechanism.

Have fun!


whats the practicality of using a planetary gearbox in vex and is a custom lexan gear box is worth it.

Hey @BlueBolts – This is the IQ forum, so we can’t make custom lexan gear boxes
In VRC a custom gearbox may make your life much easier to do some special movement. You may need some custom speed and the regular family of gears may not mesh the way you want, so a plastic frame may be the way to go.

From a design standpoint you’d most likely want to make double thick sides for the stress. I’d use the gear inserts as collars for input/output shafts so they are not rubbing against the lexan.