Trash robot

[landonmay13]

Can the following controller controll the listed movements below?
DX5e DSMX 5-Channel Transmitter/Receiver Only MD2

I am building a robot that will lift trash cans. It will do the following movements:

1. Two wheels on the bottom powered by 2 motors.
2.One motor that will lift the trash can up from the bottom (like a forklift.)
3.Two motors to sqeeze the trash can on the sides, holding it in place.

[jwatte]

What you're listing is a remote radio transmitter for model cars etc, right?
It appears to have five separate channels of information, so if you need to transmit speed (forward backward), turn, lift, and hold, that's four channels, so it should be sufficient.
You would need suitable motor controllers and limit switches or other kinds of feedback to safely actuate and operate the motors you're planning -- the receiver won't do that for you.

[waltr]

And I'd say you need a processor (Arduino will work) between the RC Receiver and the motor controllers.
The processor wiil read the 1000 to 2000usec pulse from the RC receiver and translate them to the control you want.

[jwatte]

I'd say you need a processor (Arduino will work) between the RC Receiver and the motor controllers.

A motor controller like the Sabretooth or RoboClaw can read RC pulses directly. However, if you need limit switch or other sensor support, you'd need to add logic in between.

For driving/turning, and for forklift up/down, you can probably get away with just the built-in RC support in the Sabretooth or RoboClaw, so get two of those (one for driving, one for actuating) sized appropriately for the max stall current of your motors.

[landonmay13]

Thanks for the tip!
I decided to use the RoboClaw Motor controller, but it looks like the roboclaw is a computer chip that I put on my robot to control the servos.
What device that I hold in my hand to wirelessly control the roboclaw?

[jwatte]

The exact one you asked about in the first post:

Can the following controller controll the listed movements below?
DX5e DSMX 5-Channel Transmitter/Receiver Only MD2

Hold the DX5e in your hand. It transmits signals.
Wire the receiver part that comes with that into the RoboClaw.
The receiver part turns radio waves into RC-style control pulses.
The RoboClaw turns RC-style control pulses into modulated motor power.

[mickyjune26]

Thanks for your help.  My name is Micky, and I'm Landon's dad.  We're really having fun getting into these robots.

A few final questions before we buy our parts:

0.  (yes - question zero)  Should we do this on a small scale first (like an office trashcan), or should we go for broke and build a robot strong enough for the city trash big?
1.  What servo model #s are appropriate (based on your answer to question zero)? 
2.  Is there a specific Roboclaw model # would you recommend?  We looked up Roboclaw and there were many types of models.
3.  What power source would you recommend?
4.  Is there a good tutorial site or book we could review, so we don't have to bug ya'll as much?

Thank you very much!  My son said he'd like to build robots or be a scientist when he grows up.  I'm hoping to keep these dreams alive. 
Micky

[jwatte]

Absolutely start with the little one, unless you are independently wealthy!

To figure out which motors you need, estimate the needed torque. If you direct actuate, the load is the weight of the object, times the distance between the axis of rotation and the center of mass of the object. If you use something like a linear actuator, you instead get force, so load is simply mass times gravity. You also want to pay attention on the difference between "stall torque" and "continuous torque" -- motors that work at their max (stall) load more than just briefly, will overheat and die.

Once you know which motors/actuators you need, you can pick a RoboClaw that is rated for at least the amount of current drawn by that motor/actuator. For example, if you're using a motor rated at 5A, you can use a 5A rated RoboClaw; if you use a motor rated at 20A, you can use a 25A rated RoboClaw.

[mickyjune26]

That makes sense.  Thanks for the tips!  No independent wealth here. 

Hey - any robot books or tutorials that you recommend to support this project?

[mickyjune26]

FYI - I'll be following this blog as part of this project.  Someone is building a full-size TOtT (Take Out the Trash) robot.