Hello!
I am doing a school project, and want to build a robot. I have decided to make a own topic here so I can ask question during the project. This is going to be a journey of learning for me, as robotics is not my field. I am really interested in robotics and think this project will be great for me to learn. My goal is first to make a simple four wheeled robot with mecanum wheels. I want to be able to both programming it, and remote control it with a radio controller, PS4 controller etc.
Right now I need some help to find decent motor, and motor controller. Based on my desired velocity, acceleration and incline I need a motor with a rated torque like 1,5-3 Nm, and 150-300 RPM.
I have done some research, but it is not so easy to find decent motors at regular shops (not included industrial motors). So where do you buy these kinds of motors? I am thinking DC motors with encoders, but will stepper motors be better?
These motor from Servocity does only mention stall torque, and as I can see there is not any speed-torque graph provided. I do not know how much I can expect the rated torque to be?
I have found some other stores, but I am not sure if I can trust them. Does anyone have experience with Cytron or with Robokits India? I have found these motors in these stores.
I would recommend using drivers that implement MOSFET outputs. Look at the specification of the driver you are looking at and see what the forward drop is, them multiply that times 2, that is the voltage drop across the driver. That voltage never gets to the motor robbing you of tork. A MOSFET is a very low value resistance, you will probably lose less then 0.1 V with them. Rule 1: "A power supply an Arduino is NOT!".
Paul_KD7HB:
I think. I think you need to spend some time testing a few of the motors you may use for your project.
Paul
Thanks for your answer. I agree, this is most likely the way I have to do it.
gilshultz:
I would recommend using drivers that implement MOSFET outputs. Look at the specification of the driver you are looking at and see what the forward drop is, them multiply that times 2, that is the voltage drop across the driver. That voltage never gets to the motor robbing you of tork. A MOSFET is a very low value resistance, you will probably lose less then 0.1 V with them. Rule 1: "A power supply an Arduino is NOT!".
Thanks for your answer. I will look after drivers like that.
srturner:
Is the FIRST program available in your area schools? Participating in that would be far more efficient for learning than striking out on your own.
S.
Thank you for your advice. Unfortunately, it is not available at my campus. I have looked a little bit at the FIRST, and yes it would have been awesome to be able to participate in something like that. I have to do it the hard and not so efficient way.
I am about to build this Mecanum robot. I decided that I am initially is only going to drive it with a RC-controller.
I intend to use an Arduino and Sabertooth motor controller to control it. I will try to use this code as a basis.
First, I need to ensure that I have all the components I need.
Motors:
I have four geared motors with encoders. As I am going to controll with a RC controller I, will not need the encoders. Would it be just fine to not connect the wires from the encoder and just drive it as a normal DC motor?
Motor controllers:
I am going to use two dual Sabertooth 12A.
Radio controller and transmitter.
I have some RC controllers I have used for planes and multicopters. These does only have one spring centred stick. Will a controller like that be just fine? Will different controllers and receivers affect the code?
Is there anything else I need?
In line 29 in this code it says, “Output signals for TTL Relays”. Do I need some relays or what?