[FTC]: Team 35's Servo Test

We were a bit skeptical about using the servos for anything serious, articulating arm joints for example. After our first 5 hour meeting, we are VERY excited about this new kit. We brainstormed, and then prototyped 3 different ways of articulating joint for our arm. One powered by servos, one powered by 2 Lego motors and another powered by one of the larger FTC motors.

I’m posting a Video of the servo test. We attached the bracket to the frame of last years VEX 'bot for this test. The programming was a tad off for this video (we couldn’t keep the arm at any angle we wanted). It was fixed later on, but i didn’t get my lens on it.

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how heavy is ur chassis approximately???

with the servos and stock attached: 4.676 lbs.

it’s not lifting the whole weight so that’s a tad deceiving.

That’s still pretty nice.

Well, sorry bout the double post, but 35 rings are about 6.5 pounds. With a couple o’ gear reductions…:D. I see potential.

Remember with a gear reduction of two the servo only goes +/- 45 degrees. with a ger reduction of three that would be +/- 30 degrees.

Touche, well, there are other ways to get the mechanism up without even gearing the servo. Heck, if you wanted, you could gear the servos for speed. :D.

A quick test of a 4-bar linkage with the new 2008 FTC kit. The programing is a tad off, but it does give you an idea of the power of the servos and the possibilities of the new kit. The arm was made with two 16" C-channel and a 6" short member. Our final arm will be shorter, but will look a lot like this.

We are now working on programing that does not relate stick position with servo position. We would like to have the servos act more like a motor, so that when we take our hands off the stick the arm stays where we want it rather than returning to the neutral position.

Interesting, very nicely built. A few quick questions.

  1. was the tower attached or were you or someone holding it in place?

  2. More of a suggestion, you could have the joy stick value add to the position of the encoder instead of setting the joystick value to the value of the servo.

For example:

servovalue = servovalue + joystick value;
Servo[a] = servovalue;

Where the joystick no longer equals the position of the servo. Simply changes the position.

It was attached to the front of the frame straight to the C-channel. This was not intended to be permanent, just a proof of concept. The Kids are working on a working mount as I type.

It looks REALLY good and powerful. :d.