I'm trying to set a motor to spin exactly at 60rpm, and I'm using LabView for Lego Mindstorms.

However, when reading the documentation for the move motor block, it says this:

Power/Speed specifies the amount of power, from -100 to 100, with which you want to move the motors or the speed, in seconds, at which you want to move the motors. Use the polymorphic selector below the VI icon to specify whether you want to set the power or the speed at which the motors move.

Here's a screenshot of the docs: http://puu.sh/l4FzP/c4d0b8faa7.png

So, what does the "the speed, in seconds, at which you want to move the motors." mean? I've tried setting it at one, and the motor barely moved.

1 Answer 1


A speed in second makes no sense to me.

Are there more information about this motor, like to maximum rpm/power ? If so, maybe that the scale from -100 to 100 is some sort of percentage of max rpm/power, with the positives being one rotation direction and the negatives the other ?

  • I did some research (philohome.com/nxtmotor/nxtmotor.htm), and at the same time I was tinkering with the speed in seconds setting via a PID. The speed in seconds reached 60rpm at a value between 37 and 38. The websited I mentioned before says the full-battery motor with no load is capable of ~160rpm, and the 37.5% of 160rpm is 60rpm, While this may be a coincidence and needs further testing, it could be a valid hypothesis to state that the speed in seconds represents a percentage of the max rpm Commented Nov 2, 2015 at 21:15

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