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Unread 09-02-2016, 17:36
PneumaticFlea PneumaticFlea is offline
Electroneer, Programmer, Webmaster
AKA: Lucas LeVieux
FRC #4014 (Top Hat Technicians)
Team Role: Programmer
 
Join Date: Jan 2015
Rookie Year: 2014
Location: California
Posts: 9
PneumaticFlea is an unknown quantity at this point
Which servo? What's the difference between them?

Good afternoon, Chief Delphi! This year is our team's first year doing servos, and we're unsure about which one to get. We're thinking about using a servo to position the shooter mechanism (about 60 degrees of rotation). We figure we'll need about 1.5 Nm of torque for that. We also need one for a "boot" mechanism to push the boulder into the shooter mechanism, which will need considerably less torque.

We've got quite a few questions that we thought would be best to post here.
  • We've made a spreadsheet with some options (https://docs.google.com/spreadsheets...t?usp=sharing). What are we missing? Which are the best models to use?
  • What are the benefits of a "metal gear" servo? A "ball bearing?" servo? Is it worth the extra price? What other factors should be considered besides torque and size?
  • It seems advisable to hook the power up to the VRM instead of the roborio (for current reasons). Is that legal?
  • It's also an option to gear down a bag motor and use a potentiometer in a PID loop. Is that a good idea?
  • How does one adapt the servo output onto a normal old hex shaft?