Base Gear Ratio

My team is considering using a speed gear ratio for our base. We are splitting up so that half of us work on a base with just turbo motors and no gear ratio, and the other half of us is going to work on a base with a speed gear ratio, but we’re not sure what speed gear ratio we should use. What would be ideal? 2:1, 3:2? We want to make sure we’ll be able to move around the field very quickly while also retaining much control and aim.

What kind of base is it? What size wheels are you using? What kind of bot are you? These are all questions to ask when doing any gear ratio to your base.

Take note that aim is not relevant in this game, but I see how you need control in order to pick up your stars. Before calculating your gear ratio, I would set up a spreadsheet to calculate your speed and your required weight so you can easily plug in values into your formulas. Keep in mind of the friction with the wheels and the ground (the coefficient of friction between rubber and rubber is 1.16). The size of the wheels and the weight of your robot also matters.

Aim will be more relevant later on I think. I am thinking of Starstruck as a doubles tennis (or badminton match or beach volleyball) but with a multitude of objects being sent across the net.

Near court and far court strategies require aim to place the elements where it is most time consuming for your opponent to react. So maybe not precise aim to a small triangle (like last year in NBN), but some gross aiming technique to maximize the expected lifetime that object lives on the opposite side of the field.

I prefer the high speed motors with 3.25 in wheels. Or you could do high strength motors with 4 inch wheels

Personally I think direct is best

On almost any robot you can do direct drive with High Speed gearing without any ill effects.

tell that to my behemoth from last year that couldn’t manage 4 on torque with 2.75" wheels without burning out. It was bad.

Dang dude, that’s crazy, especially for nbn…

The robot was nearly entirely steel due to funding concerns, and we just slapped more on there whenever something started bending…still made it to worlds though!

Vex mechanum wheels are very heavy and inefficient though and I wouldn’t recommend gearing higher than direct drive torque motors unless you have a really light clean build.