Thread: Team Update #18
View Single Post
  #221   Spotlight this post!  
Unread 17-03-2011, 23:14
boomergeek's Avatar
boomergeek boomergeek is offline
Registered User
AKA: Mr. D (Dick DiPasquale)
FRC #0241 (Pinkerton Robotics)
Team Role: Mentor
 
Join Date: Feb 2009
Rookie Year: 2009
Location: Derry, NH
Posts: 191
boomergeek has a brilliant futureboomergeek has a brilliant futureboomergeek has a brilliant futureboomergeek has a brilliant futureboomergeek has a brilliant futureboomergeek has a brilliant futureboomergeek has a brilliant futureboomergeek has a brilliant futureboomergeek has a brilliant futureboomergeek has a brilliant futureboomergeek has a brilliant future
Re: Team Update #18

Quote:
Originally Posted by Ether View Post
16.8 watts max power output w/o gearhead

= 12.4 ft-lb/sec

x2 motors = 24.8 ft-lb/sec max power output

2.3 lb estimated robot weight

(24.8 ft-lb/sec) / (2.3 lb) = 10.8 ft/sec (neglecting friction)

Here's a different way to get at approximately the same point.

At kick off, the video of the FIRST built minibot showed about 1.3 ft/sec for a robot that looked to be more than 5 lbs and using a pair of Tetrix motors and gearboxes.

Its not hard to cypher that a 2 lb robot can be 2.5 times faster than a 5 lb robot. By the same token, if you throw away a near 50% inefficient transmission, you should be able to obtain another doubling of speed. That gets you in the 7-8 ft/sec range. Add additional lowering of friction in the attachment to the pole mechanism and you approach the magically 10.8 ft/sec. Add topping off the battery to get to a better motor curve is gravy on top.
Reply With Quote