Thread: Need advice on motors, gearboxes, and ESCs
View Single Post
  #24   Spotlight this post!  
Unread 27-02-2014, 12:28
protoserge's Avatar
protoserge protoserge is offline
CAD, machining, circuits, fun!
AKA: Some call me... Tim?
FRC #0365 (MOE) & former 836 Mentor)
Team Role: Mentor
  
Join Date: Jan 2012
Rookie Year: 2002
Location: Wilmington, DE
Posts: 751
protoserge has a reputation beyond reputeprotoserge has a reputation beyond reputeprotoserge has a reputation beyond reputeprotoserge has a reputation beyond reputeprotoserge has a reputation beyond reputeprotoserge has a reputation beyond reputeprotoserge has a reputation beyond reputeprotoserge has a reputation beyond reputeprotoserge has a reputation beyond reputeprotoserge has a reputation beyond reputeprotoserge has a reputation beyond repute
Re: Need advice on motors, gearboxes, and ESCs
Quote:
Originally Posted by Nathan View Post
Thank you all again so much for your advice. We've decided to go with the CIM motors (full size) and VersaPlanetary gearboxes.

With a 5:1 gearbox and 6" wheels, that gives us 1717 oz-in (107.3125 in-lbs) of torque with a speed of 6MPH.

Do you think that's enough torque to move a ~60lb robot?

I attached a spreadsheet with our list of parts and speed/torque calculations. Any final advice you could give us would be great!

Thanks!
If I'm correct, your calculations are based on the motor free speed (CIM is ~5100 rpm). Once loaded, this speed will be reduced. You should expect about 4100-4300 rpm at peak efficiency loaded. The JVN calculator uses an 81% "speed loss constant". You may want to reference this for your calculations.

Overall, not a bad start

By the way, I'd encourage you to check out the Mars Society's University Rover Challenge next year.