Sooo, SPIN UP META IS...? 😮

[ThoughtfulTexan]

Best practice is to not assume other folks use the same convention as you do, and clearly label your ratios. Especially when the conversation includes a diverse population of students at a variety of ages, across multiple countries.

Fact of the matter is that it depends what you’re aiming to express (torque v speed) and then what you’re using as your inputs. Different industries and professions have different conventions.

Check out this entire discussion on the issue.

Gear Ratio's - How to properly show them?

Gear ratio is an ambiguous term in my opinion. People can take it to mean tooth ratio, speed ratio, or torque ratio. You are better off using one of the latter two when referring to your gear train. I looked back in my textbooks and couldn’t find “gear ratio” anywhere. The second issue is that it is not clear what goes first, input or output. In my experience it has always been the latter (output:input). So a speed ratio of 3 has the output turning faster than a speed ratio of 2.

Edit to add, this official document from Vex about how to use gear ratios sometimes has the driven gear first - https://kb.vex.com/hc/en-us/articles/360035590932-Using-Gear-Ratios-with-the-V5-Motor