Servo Question

[pollyproof12]

i am looking at servos because i do not know how many we can have and of what type. i noticed on the manual it said that we could use the ftc servo but i do not know what that looks like or where to find it. is there a limit on how many we can use? also in>>> Max Effeciency: 4313 RPM, 33.2 oz-in, 10 A<<< what does the 33.2 oz in mean?

[samir13k]

I am pretty sure our team used servos by "HiTec" hobby servos. You can find them pretty easily on google shopping. Also, i have a hunch they were bought at a local hobby lobby, but i'm not positive on that one. I also believe that it is fair game to use vex servos. As for limits on the amount of servos, i have no clue.

[EricH]

HITEC HS-322 servos, FTC (VEX System) servos and motors (Innovation First 276-2162 and 276-2163), unlimited quantity (no limit specified, so assumed to be as many as you have output ports for).

Please note: This is from the 2008 manual and is subject to change for the 2009 game. I would expect it to change, because the VEX servos and motors are not used in FTC anymore to my knowledge. (Probably just a wording change...)

And for the other question, oz-in (along with N*m and ft*lb) is a unit of torque. 33.2 oz-in means that a servo can output 33.2 oz of force at one inch, or 1 oz of force at 33.2 in, or some similar combination in between, as long as the force times the distance is 33.2 oz*in.

[pollyproof12]

thank you

[samir13k]

what is the purpose for the servo? They are often used for small things like cameras. Servos are only meant to make partial rotations. basically the full servo rotation would move something an inch up and down if that is what you intend on using it for. 33 oz means that it can basically lift something up to 2lbs in weight.

[EricVanWyk]

Originally Posted by pollyproof12

so u mean it can only move 33 oz for an inch and then it has to stop? i do not understand. please bear with me.

http://en.wikipedia.org/wiki/Torque

It means that it can exert 33 oz of force with a 1 inch arm, or 1 oz of force with a 33 inch arm.

[vivek16]

oz-in is a representation of torque. Torque is the rotational force on an axle/joint.

if it has 33 oz-in it means that if you put an arm on the axle, it will only be able to push 33 oz worth of force.

Another representation of torque is ft-lbs and Newton Meters. You can find conversions at this link: http://www.chiefdelphi.com/media/papers/download/2303

Hope it helped.

-Vivek

[pollyproof12]

another question. how do i create a vi that allows me to move the mouse on my screen?

[Joe Ross]

Originally Posted by pollyproof12

another question. how do i create a vi that allows me to move the mouse on my screen?

You can get mouse coordinates and button presses from the VIs in Connectivity->Input Device.

[pollyproof12]

in the 2008 manual it never said teams could not use linear actuators. is it considered a motor?

[EricH]

Originally Posted by pollyproof12

in the 2008 manual it never said teams could not use linear actuators. is it considered a motor?

Good question, but the answer is that it is considered a motor if it has a motor. From the 2008 rules:

Originally Posted by Section 8

<R60> Items specifically PROHIBITED from use on the ROBOT include:
 Electric motors and/or servos different from, or in addition to, those in the Kit Of Parts, with the exception of those specifically permitted by Rule <R59>.
 Electric solenoid actuators (note: electric solenoid actuators are NOT the same as pneumatic solenoid valves – the latter are permitted, the former are not).

If it has a motor that is not KOP or otherwise specifically allowed, it is absolutely not legal. Someone did ask in the Q&A about this exact situation, and the response was effectively the one I just gave.

You can have a linear actuator that is powered by a KOP motor, or is an allowed pneumatic cylinder.

[Obligatory note] All rules are subject to change for the 2009 season.

[Andrew Schreiber]

Originally Posted by pollyproof12

i know we ar getting different equipment and the games is also, but will the rules change that drastically

It is possible the rules will change that drastically. But it is also possible that, with the exception of the controls we will get the same KOP and the same rules. Nobody except Dave Lavery and the rest of the GDC knows but they either aren't telling or, in Dave's case, should be banned this time of year.

Off topic but there should be a key labeled shift in the bottom left and right of your keyboard, could you please use it. Also, please proof read your posts. I don't say this to be a jerk. I mention it because I think it is necessary for a person to communicate effectively and poor grammar,spelling, and punctuation make you appear less intelligent than you are and I don't think you want that.