Changing motor speed

New to Vex IQ. I have downloaded ModKit. Can anyone walk me thru the process to change speed on one motor. I have the bot set up on ModKit (brain, 5 motors, bumpers), but can’t locate where to adjust speed on a motor.

In ModKit there are two ‘views’. Robot or Blocks. Click the Blocks icon at the top of the screen in the center to select the blocks view. When you are in the blocks view there are tabs for each robot component. Select on of the Motor tabs. Once you are have a motor tab selected the list of blocks (on the left of the screen) that you can select will change to those that are applicable to a motor. Scroll to the top of the list and select the dark blue Set Velocity block. Note that if your motors are in a Rotator or Slider, then there is a Set Speed block, instead of Set Velocity. If they are part of a drivetrain then there are settings for Drive Speed and Turn Speed. Hope that helps.


Let me know what you are trying to do, like use a button to lift an arm to a specific position, and I can provide more details or a sample program.

We are using a motor to lift a dump, like a dump truck. Ideally, we’d like the gear to only spin about 45-60 degrees, then go back down. Right now, I cant get any programming to transfer to the brain, but cannot figure out why. It transferred the first few times, but no longer will process.

We discovered that it is downloading to slot 4 (so will manually trigger the autonomous action), but those settings are not carried over to driver control. The point in slowing the motor is to make it less ‘jerky’ so that our kids are better able to control the up/down, without having to quickly push/release the button. Is this more of adjusting the controller?

The USB connection can be touchy, especially on Windows. Try any one or all of these until it works again: turn brain on and off, unplug and replug USB cable on either end, try another USB port on your computer, restart Modkit (save first).

I would recommend using a Rotator in Modkit for the lift, not just a plain old motor. With a rotator you can add a second motor and ModKit will keep them in sync. In this first sample there are two pre-set positions for the lift, up and down, and the left buttons control it. L-Up goes to 60 degrees, and L-Down goes to 0. The user does not need to hold the button down, just press it once and it will go to the preset position. Note that the Holding is set to ON. If you don’t set holding on then the dumper will go to 60 degrees and then slowly fall back down.

The second sample is for a manual mode and uses two buttons to go up and down, but it does not use pre-sets. When the user is holding the R-Up button the lift moves up. It stops moving as soon as the user stops pressing the button. The R-Down button goes in the opposite direction. Note that there are separate events for pressing the button and letting it go. If you didn’t have the STOP block when the button is Released, then the motor would keep going until it got stuck or ripped the lift apart.

You could also have a program with one set of buttons for preset positions and another set of buttons for manual control.



Ok, so I’m not understanding how this carries over to Driver Control. This info downloads into Slot 1-4, but I can’t get it to carry over to DC. I apologize, we are all totally new to vex/programming. Thank you so much for your help already.

After you download the program to slot 4, you have to use the arrow keys on the brain to select the program in slot 4, and then press the check to run it. You will no longer run Driver Control. Driver Control does not change.

Also make sure that you are dragging the controller onto your program, and that you have included the Drivetrain in your program and mapped the joysticks to it. Once you stop using Driver Control you need to write your own driving routine. In this screen print I have the left joystick mapped to the drivetrain going forward and back, and the right joystick for turning.