How powerful are these robots?

Before I get a starter kit, I just want to know if it is possible to make a robot about 30cm x 30cm that can move 5 - 6 kg at a reasonable speed. Thanks.

My Hero 2007 Robot and Gilbert III Explorer robot can move a laptop around a room and the Bionic Arm can easily lift five pound weight. You can see photos of these Vex based robots using the following link:

Yes, its all about the gears and the motors.

The motors are ok, they can provide a good amount of torque/pulling power.

The main thing is the gears, you could lift a car with a tooth brush motor! Why well because of gears.

I have seen robots on this forum that can lift a 25lb weight, you are talking about hauling the weight on a robot.

That is much easier, the weight will increase traction on the wheels and then all you have to do is find out how much power you need to move the weight. From there you use the appropriate gear, depending on what gears you use you can increase speed and torque but you have to sacrifice one for the other.

5kg is not much, its roughly 11 lbs which is a good load for a robot and i am assuming that you are building some form of carrying robot.

Basically anything is possible with vex, if you can afford it i urge you to get the programming kit its $99 but it is so useful its unbelievable.

When you get the kit it has a program already on it that has corresponding motor ports to the controller. This gets really annoying, you have to rearange motors and buy special cables if you want to run multiple motors off 1 channel. With the programming kit you could change the micro controller to conform to your needs which is a godly power that you must have.

Not to mention ultrasonic sensors, light sensors and much much more, with the programming kit you think of what you want the robot to do and program it and then the robot does what you want you don’t even have to control it. The robot can go about its business all on its own if you program it to be autnomous meaning you don’t have to do a thing but watch it go.

If you have any questions just ask.

After using some gears to increase the torque, would I be able still speed it up by simple putting more current through such as adding another battery pack on parallel? Also, would i need more metal parts, gears, etc. than those that come in the kit to complete the task of moving around with a 6 kg weight on top of the robot. I really appreciate your help.

I would not put more current through the motors, if you plan on using the vex micro controller you cannot put out more than 2amps per motor. The vex micro controller has a total of 4 available amps for use by sensors and motors.

To increase speed you would have to increase the voltage but the vex micro controller is capped at 7.5v i believe.

So unless you plan on using a non vex micro controller you cannot increase the speed of the motor by increasing current or voltage.

This has been a problem that many people have addressed, the motors are simply to small sometimes and people want higher speed motors. So far i have not heard of any plans to build a new motor.

Basically as i said you have to sacrifice one for the other, the only way to get around losing speed is to add more motors and reduce gearing but at $20 per extra motor its not exactly cheap.

4 amps doesn’t seem like a whole lot. I’m trying to replicate my current robot with vex and it runs on 18 AA batteries;7.2v. Since I can’t exactly imagine what 4 amps is like, how many batteries does it run on?

edit: ok I’m acting very stupid for not know what an Amp is. After some research, I realize 4 amps is A LOT of current. sorry about that

The vex can run on 4aa battery’s but 6 is for max performance.

If you want to talk about current you should see this motor i have in my basement. It draws so many amps that it melted the plug in the wall in only 5 seconds, we got it for $10 and its 7hp electric so you can’t complain it retails for over $300. Someone disconnected a wire on the inside and called it “Broken” well in my eyes a little solder and a wire stripper can fix that! 20 minutes later i got it to work lol.

The Vex Controller and Vex motors work much faster using the Vex 9 volt rechargeable battery. I use it for most of my projects with no problems, and it even works fine with the Vexplorer.

If you can put up to 2 amps out per motor, wouldn’t adding another 6 or 12 batteries on parallel be fine? Also, hearing that 6 batteries can still create a powerful robot, how fast do the batteries drain?

@tswift1- I thought you can only use a max of 7.2v for the micro controller?

You can also use the 9-Volt rechargeable battery pack on both the Vex Controller and the Vexplorer Controller and it conveniently has the same connector as the 7 Volt rechargeable battery . The Vex motors will run faster with more torque using 9 Volts. The Vex and Vexplorer controllers have no problems with supplies up to 9 Volts but I would not use any higher voltage batteries.

The Vex Controller limits the current to each Vex motor or Vex servo so connecting the batteries in parallel will only increase the length of time the motors will run. The current drawn depends on the internal resistance of each motor using Ohms Law, the PWM Frequency and PWM Duty Cycle.