Thread: RS775 Gearboxes
View Single Post
  #6   Spotlight this post!  
Unread 17-01-2011, 02:14
rahilm's Avatar
rahilm rahilm is offline
Registered User
AKA: Rahil Mehta
FRC #0668 (The Apes of Wrath)
Team Role: Mentor
 
Join Date: Oct 2009
Rookie Year: 2007
Location: San Jose, CA
Posts: 116
rahilm has a spectacular aura aboutrahilm has a spectacular aura about
Re: RS775 Gearboxes

Quote:
Originally Posted by Chris is me View Post
4 is complete overkill. They're roughly 240W motors if I recall correctly - think the equivalent of a 2010 FP motor.
~390 if I did my math correctly; ~(voltage)*(stall current)/4 = (12)*(130)/4 = 390 (not factoring in motor inefficiency)

Also, the 2010 FPs had roughly 190w. This year's have 290w. (Both figures from the FIRST motor curves)


Quote:
Originally Posted by noa_n_f View Post
Thanks for the fast responses. If I go for two RS775, what typ of gear ratios should I be looking for? It will be a parallel lift with a diagonal surgical tubing assist. I'm looking to making the arm raise and lower as quickly as possible without worrying about the motors not being able to handle it.
The reduction we're going with is a 512:1 (256:1 with banebots gearbox, and then 2:1 with sprocket). This gives us ~576 lb-ft of torque if you go with 65% gearbox efficiency, which is more than enough to lift it, while we still have 25RPM, which is 150deg/s.
__________________
Team 668 - Apes of Wrath - 2008-2011
Team 668 - Apes of Wrath - 2011-Present (Mentor)

Last edited by rahilm : 17-01-2011 at 02:19.