9 ft/sec for an 8" wheel drive?

[JesseK]

It's difficult to calculate all of that stuff using JVN's sheets alone. JVN's has been irreplaceable in its cross-references of gearboxes this year, but that one piece means it shouldn't be used alone.

Search CD-media for 'calculator'. There are tons, each with their merits.
Here is mine, but I haven't updated it in a long time so the motor data is invalid. There are also a couple of nuances:

• Mecanum selection improperly reduces applied torque for acceleration
• "Time To Goal" is the old nomenclature for the modern "Sprint Distance"
• It doesn't account for battery voltage, so there is error of about 3% in the time and current draw calculations - small, but still not exacting. Accounting for battery voltage and then solving for 't' is actually very difficult.
• "Actual" Speed varies a bit because it measures time from t=0 to the amount of time it takes to get to the goal, rather than calculating a maximum speed. So a new version of this sheet would include that as well.

Attached is a notional output for one specific scenario (but not necessarily what we will end up with).

[cbale2000]

It only works with Vex Gearboxes, but I personally use this tool a lot for drive calculations:

http://www.wcproducts.net/how-to-drivetrain/

My only complaint is that the units aren't labeled so you have to assume what units they're using.

[billbo911]

Originally Posted by cbale2000

It only works with Vex Gearboxes, .....

Sorry, that is incorrect.
The sheet is populated with values based on Vex gearboxes, but every (pink) field can be edited. You can make these sheets work for just about any gearbox, intake, linear drive, etc. mechanism you can think of.

[cbale2000]

Originally Posted by billbo911

Sorry, that is incorrect.
The sheet is populated with values based on Vex gearboxes, but every (pink) field can be edited. You can make these sheets work for just about any gearbox, intake, linear drive, etc. mechanism you can think of.

Might want to reread my post, I was referring to the fact that the calculator on this website only works for Vex gearboxes.