Go to Post The difference between a robotics kid and a generic nerd. Both use their calculators for statistical analysis. One keeps it a closely guarded secret, the other brags about it on Chief Delphi! - Kevin Leonard [more]
Home
Go Back   Chief Delphi > Technical > Technical Discussion
CD-Media   CD-Spy  
portal register members calendar search Today's Posts Mark Forums Read FAQ rules

 
 
 
Thread Tools Rate Thread Display Modes
Prev Previous Post   Next Post Next
  #11   Spotlight this post!  
Unread 18-12-2006, 18:00
Greg Needel's Avatar Unsung FIRST Hero
Greg Needel Greg Needel is offline
REVving up for a new season
FRC #2848 (All-sparks)
Team Role: Engineer
 
Join Date: Jan 2002
Rookie Year: 2002
Location: Dallas, TX
Posts: 3,111
Greg Needel has a reputation beyond reputeGreg Needel has a reputation beyond reputeGreg Needel has a reputation beyond reputeGreg Needel has a reputation beyond reputeGreg Needel has a reputation beyond reputeGreg Needel has a reputation beyond reputeGreg Needel has a reputation beyond reputeGreg Needel has a reputation beyond reputeGreg Needel has a reputation beyond reputeGreg Needel has a reputation beyond reputeGreg Needel has a reputation beyond repute
Re: Tripping breakers

While many people in this thread are on the right idea, the real trick to this is to design a gearbox based on the current draw. Assuming that you are looking to get maximum torque you should design your gearbox to pull just under 40 amps at maximum torque. This requires you to know the approximate coe of friction with the playing field surface, determining motor torque based on amperage, the approximate gearbox Efficiency, and your normal force.

Assuming a flat surface:

Max Force= Force friction = (Coe of Friction) * (total Weight)

Force = (Torque at the wheel) /

Torque at the wheel = (Torque at 40Amps)*(Gear Ratio)*(Gearbox Efficiency)

So substituting Forces you get:

(Gear Ratio)/ (Wheel radius) = ((Coe of Friction) * (total Weight))/ ((Torque at 40Amps)*(Gearbox Efficiency))


Standard Efficiencies for drives:
Chain drive 95-98%
Spur Gears 95-98%
Bevel Gears 90-95%
Worm Drive 40-70%
Planetary 80-90%

This will give you the optimization of pushing force and gear ratio for a drive train which you can then use to find your maximum speed. If you want to have a greater maximum speed you can decrease the ratio at the cost of torque. Design is all about tradeoffs but this is a good place to start.
__________________
Greg Needel│www.robogreg.com
Co-founder REV Robotics LLC www.REVrobotics.com
2014 FRC World Champions with 254, 469, & 74
 


Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Guy tripping on escalator jhnphm Chit-Chat 22 28-04-2005 19:30
breaker tripping on robot startup Bleric Electrical 2 12-02-2005 10:25
Tripping 120Amp Andy144 Electrical 26 01-04-2003 09:28
Circuit Breakers: Tripping Al Skierkiewicz Electrical 7 10-04-2002 12:40
tripping breakers/burning motors Ben Mitchell Motors 16 04-02-2002 13:31


All times are GMT -5. The time now is 06:33.

The Chief Delphi Forums are sponsored by Innovation First International, Inc.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Copyright © Chief Delphi