Four wheel drive for V4?

So I work with High School kids and our staff who ran the robotics has moved and I am trying my best to help the kids! So we built our robots and they all wanted 4 wheel drive so the robots have 4 wheels attached to 4 motors. I have plugged them into the motor ports and I have been moving them around because I can only ever get 2 of the motors to work. How can I get all four to move??
I should also mention that we have the VEX V4 kits so they have the VEXnet keys so I haven’t had to do any programming yet I have just paired the robots and their controllers.

Thanks!!!

If you look at the docs and downloads, you’ll see the instructions for the Cortex. There are pin locations for not only the 4 wheel drive you are looking for, but also SIX wheel drive!!

Good luck!

10 Likes

If this is for competition and not classroom use I highly recommend a 6 (or even 8) motor drive. If you are competing with v5 robots you will be severely outmatched in pushing power and speed. Even a 2 motor v5 drive will outmatch a 4 motor v4 drive. If this is for classroom use 4 motors is perfectly fine.

2 Likes

This is not for competition it’s just for fun! They are also V4 robots only :slight_smile:

I still am struggling to figure out how to get all four motors to work however! Either just two are working, or if I try to plug the motors into a different port then all four will work but two wheels will continue moving on their own without use of the remote control!

1 Like

Thank you for this resource ! I am still unsure of which ports I should be plugging the motors into as I have tried a number of combinations and so far just two motors will work, or all four work but two of them will continuously move without using the remote controller.

If you continue to run into issues, please don’t hesitate to get in touch with our Customer Support team. They’ll be glad to walk you through any questions you may have!

Email: support@vex.com
Phone: (903) 453-0802

10 Likes

Just to verify, for the motors you are using in ports 1 and 10, you are using just the motor. The other ports you need to use the #29 motor controls. The have 3 wires on one end that plug into the Cortex, the other end has 2 wires for the motor.

The link I sent you has a chart that tells you what ports are for the left motors, and what are for the right motors.

This is also assuming that you have the default program loaded, and that someone hasn’t reprogrammed the Cortex. Default software can be found on the link I posted.

6 Likes

I was using the motors for two yes and motor controllers for the other two. I will try today at work to see if I am able to figure out the right ports I think that my issue is not understanding which ports should be for each motor! Thank you so much for your help I’ll keep you updated!!

1 Like

This is why it’s failing. You need to use motor controllers on all motors, or else they won’t work. Trust me, I’ve been using Cortex for competition for the last few years.

2 Likes

This is the document you’re looking for - it contains a lot of useful stuff but the info relevant to this question is on pages 6 and 7:

Assuming your Cortex is running the default program (i.e., the program hasn’t been overwritten), you’ll want to connect the left drive motors to ports 2 and 3, and the right drive motors to ports 4 and 5, all 4 through motor controllers. Then stick a jumper in Digital port 12 for arcade drive or leave the jumper out for tank drive.

4 Likes

You don’t need motor controllers in ports 1 and 10. Go look, there are only two pins in those ports.

https://vexwiki.org/vex_robotics_platforms/vex_edr/cpu/cortex/motor_ports

4 Likes

Oh, I didn’t know that.

2 Likes

OK, just wanted to make sure @Robots4beginners didn’t get confused. Thanks!

2 Likes

Thank you so much this was extremely helpful, I will try this out!

1 Like

Just an update for everyone, I appreciated all of the help and useful resources! I ended up just using RobotC and telling the robot which motors were in which ports and used a continuous loop so that it could be remote controlled and managed to get all four motors working!

6 Likes