pic: Sheet Metal with VexPro parts

[billbo911]

Originally Posted by Madison

The chain reduction is 1:2 right now; 16 tooth hex sprocket to 32 tooth sprocket bolted to a versahub..........

Considering drive train design is by no means my area of expertise, I lean heavily on what I see other teams doing successfully and try to apply their knowledge in a way that supports our needs. I also make use of tools like the JVN Design Calculator for convenience.

What I'm looking for is some basic "Rule of Thumb" target numbers to use to help determine overall drive train gearing.

Let's assume we will be using 4" wheels.

Here are some first pass numbers I came up with using the JVN Calculator, do these look like a good starting point? Game requirements will need to be considered once we KNOW what the game is, but for now, are these numbers close? If no, why not?


VEXPro 2 speed Ball Shifter:
2 CIMs per tramsmission:
4" wheels:
Additional chain reduction of 28:16:

Low gear total reduction 14.6:1 Max speed = 5.33 ft/sec. Wheel stall 58 Nm
High Gear total reduction 6.4:1 Max speed = 12.12 ft/sec. Wheel stall 25.16 Nm

From your experience(s), are the numbers in the ballpark? Remember, I'm just looking for "Rule of Thumb" and why they are right or wrong.