VEX 393 Motor Resistance

Hello - I used a multi-meter to measure the resistance of the VEX 393 2-Wire motor and got 3.6-Ohms. I did this by simply putting the leads of the meter to the prongs on the motor plug. Why am I getting more than double the spec. resistance of 1.5-Ohms?

No idea, I just checked a motor here, it was 1.4 ohms. Is it a good meter?

It’s a cheap Radioshack multi-meter. No problem, I’m just showing the kids how to calculate the back EMF voltage based on supply voltage and measure current based on a certain torque/rpm. I’ll just assume the resistance of the 393 armature is 1.5-ohms. Thanks so much for your on-going support.

Hey I know this is an old post, just joined the forums. My team has been doing some detailed study on these motors. The problem with measuring the motor resistance (induction motor) is the position it’s in has to be perfect. Once it spins a bit you will read more resistance. This is so the motor can spin the whole way around and not be blocked by the magnetic force that pushed it in the first place. Youtube “homemade motor”.

This isn’t an induction motor, it’s a permanent magnet motor. The reason it measures different values as you rotate it is because the brushes vary in contact.