[FTC]: [FTC]: Can any one explain to me just how powerful the servos are?

[sullivan_owns]

hi, please explain to me what is the max. the servos can hold? and will they work for telescoping ideas???
Oh, and i almost forgot, which is better/more powerful, the servos or the FTC motors?? and one last question can you use the drive motors for raising and working the arm???

[KayyPii]

I dont remember the exact power that the servo can produce, but they are way weaker than the FTC motors. I would personally use motors to make an arm unless you want to gear 4 servos together.
The disadvantage however to using motors is that 1. you have to purchase another tetrix motor controller and 2. it is heavier than servos.

[sullivan_owns]

o hey thx but i made i mistake to my form, i meant which is more powerful servos or NXT motors???

[wilsonmw04]

Greetings, and welcome to CD. You have asked a lot of questions in you post. I'll do my best to answer as many as i'm qualified to answer.

can you use the drive motors for raising and working the arm???
Yes, you can use the motors for anything you wish. My team is using the 4 large motors to run 1 wheel each. That leaves us with the servos to run an arm. I have seen several teams using two large motors to drive with (one on each side) leaving the other two "drive" motors to run anything else they wanted to put on their robot.

which is better/more powerful, the servos or the FTC motors??
it depends on what you what the motors/servos to do. if you are looking for power, or if you need somthing to turn more than 180 degrees, the motors are your choice. Servos only turn ~180 degrees and are far less powerful than the drive motors. Servos do have some advantages over motors. They return their "center" when releases and they can tell where they are in relation to that center.

hi, please explain to me what is the max. the servos can hold?

I believe the servos are rated for 61 oz/in of torque. That means, it can turn with a weight of 61 oz on an arm 1 inch long. As your arm gets longer the weight that you can put on the end of it decreases.

Feel free to ask more questions, but let me point you to the link to the FTC manual. This can answer any questions you have about, what you can or can't do with the kit in building your robot this year.

[sullivan_owns]

o hey thx alot that realli helps, but i also made i mistake to my form, i meant which is more powerful; servos or NXT motors??? and what are there pros and cons

[wilsonmw04]

ok Servo vs NXT motors...

Power wise? the NXT motors hands down.

Pros and cons:
Supposedly, the NXT motors have an encoder in them that can determine 1 degree of rotation. If that's true, and you can get it to work, that could be a VERY power motor to use. The HUGE negative to the NXT motor is the shape and the difficulty of matching it with the Tetrix metal.

The servos have hard stops which can make programing easy. The biggest problem with the servos are the relative lack of power and the fact they only have 180 degree rotation.

[ttldomination]

Originally Posted by wilsonmw04

The biggest problem with the servos are the relative lack of power and the fact they only have 180 degree rotation.

Don't let power stop you though. There are many "legal" ways to enhance the servos so that they lift an arm, let's say...11" long with about 7 pounds attached to the end. Yes, the torque needed to lift that is crazy, but there are ways to enhance the system to cause the arm to lift.

Well...not enhance the servos, just enhance the arm lifting system. .

Trust me, there are ways. Yes way*s*.

[sullivan_owns]

Is it possible to modify the servos so that they can rotate more 180 degrees, if soo is that allowed for the FTC.

[gdo]

According to ServoCity, here are the servo specs

Control System: +Pulse Width Control 1500usec Neutral
Required Pulse: 3-5 Volt Peak to Peak Square Wave
Operating Voltage: 4.8-6.0 Volts
Operating Temperature Range: -20 to +60 Degree C
Operating Speed (4.8V): 0.23sec/60° at no load
Operating Speed (6.0V): 0.18sec/60° at no load
Stall Torque (4.8V): 61 oz/in. (4.3kg.cm)
Stall Torque (6.0V): 76 oz/in. (5.5kg.cm)
Operating Angle: 45 Deg. one side pulse traveling 400usec
360 Modifiable: Yes
Direction: Clockwise/Pulse Traveling 1500 to 1900usec
Current Drain (4.8V): 8mA/idle and 150mA no load operating
Current Drain (6.0V): 8.8mA/idle and 180mA no load operating
Dead Band Width: 8usec
Motor Type: 3 Pole Ferrite Motor
Potentiometer Drive: Indirect Drive
Bearing Type: Top Ball Bearing, Lower Bushing
Gear Type: Karbonite Gears
Connector Wire Length: 11.81" (300mm)
Dimensions: See Schematic
Weight: 1.4oz (39g)

[ttldomination]

Originally Posted by sullivan_owns

Is it possible to modify the servos so that they can rotate more 180 degrees, if soo is that allowed for the FTC.

Modifying the servos would be against the rules. Electronic devices or motors/servos cannot be altered in any way. .

[sullivan_owns]

hey thx guys you have been great helps, but just to make sure altering or modifying any structural parts IS alowed right???

[wilsonmw04]

Originally Posted by sullivan_owns

hey thx guys you have been great helps, but just to make sure altering or modifying any structural parts IS alowed right???

again, check the rules for the official answer, but yes. Altering structural parts, in general, is allowed.

[ttldomination]

Well, not exactly. Structural parts cannot be welder, soldered, brazed, or glued. .

Yeah, read the rules. http://www.usfirst.org/uploadedFiles...he%20Robot.pdf .

That link will take you to the robot section of the manual, this will tell what all you can or cannot put on ur robot and what you can do to metal and stuff.

[Klaatu51]

Originally Posted by ttldomination

Modifying the servos would be against the rules. Electronic devices or motors/servos cannot be altered in any way. .

Not allowing servo hacks is just plain too autocratic, imho.

Lets all email the power brokers and ask for this rule to be moded?

[sullivan_owns]

thx and i was also wondering, for on the NXT motors can we tread the 4 orange cirles so that we can put screws in it???