Diagnosing motor problems

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While I can't provide a complete list, the following information may be helpful. These suggestions should only be performed by someone familiar with high amperage DC motors.

Place the unit on a workbench

Then turn the motorboard over so that the deck is resting on the workbench. You may need to lower the handlebars so that the handlebars don't hit the floor. Turn the unit on.

Check for obstructions

Slowly rotate the wheel with your hand. Listen and feel for obstructions, broken or loose bearings. Feel the side of the wheels, check for notches, cracks or an uneven ridge. Wiggle the wheel from side to side to check for loose bearings. Clean wheel with small amount of alcohol. Sand down uneven ridges or raised areas. Remove wheel and use compressed air and/or an old toothbrush to clean out debris. Replace wheel.

Operate motors

Place a rubberband on the throttle so that it is 1/3 to 1/2 depressed. Quickly spin wheel with your hand. The motor should begin to operate. Check for clicking noises, or other rough noises. Lightly check power of wheel. Check if system accelerates and accelerates by itself. It seems to help to leave the motor running for 15 minutes or so.

Check that both motors are operating properly

With the motorboard operating as described above, remove bolt from rear wheel. While wheel is spinning, remove rear axel. The wheel should fall out and the motors should keep running. If both motors immediately stop, this means that the chopper side motor is not functioning. Carefully check that both motors are operating at full power.

Check each motor individually by disconnecting the other

Using the instructions provided by Go Motorboard, remove the deck, brake cable, disconnect battery, etc. Invert motor housing on and screw it on upside down (with motors facing upward). Disconnect the cable of one of the motors. With system OFF, carefully reconnect battery (warning strong current!). WIth rubberband on throttle as above, turn unit ON, and spin the wheel quickly by hand. Check for noises and motor power. Turn unit OFF. Reconnect motor and disconnect the other. Check for noises and motor power. With unit OFF and battery disconnected, clean motor contacts and make sure they firmly connect with motors.

Try operating the unit on low voltage, without Motor Controller

Remove wheel. Disconnect one motor. Take two 1.5 volt batterys and connect them together. Check the two batteries to the motor and see if it spins smoothly. Check if needs to be spun by hand.

Try operating the unit on maximum voltage, without Motor Controller

If one suspects the Motor Controller of being faulty, it is possible to connect the motor (or motors) directly to the battery. The motors will operate at full speed and full power.

One community member connected the NiMh battery pack directly to the 2 motors during a cleanout dismantling. He did this to fully drain the battery for battery maintenance.

He made two “Y” cables with female insulated “crimp-on” blade connectors on the ends. He used a multimeter to find the polarity of the battery. The motors are easy to find the polarity because the Motor controller red wire is positive.

Battery to Motors Y cables.jpg

Note: This should be done with extreme caution when using any kind of lithium battery, (such as the packs from the XR series of boards, or any custom lithium-based packs,) because these batteries are extremely sensitive to low voltages, and should not be brought below their recommended voltages.

Mechanical Connection

The motor is held on to the motor sled by two screws. All the weight of the ride falls (at an angle) on these two screws. If one becomes loose or broken, the motor will swing away from the wheel and the chopper. This will result in clicking, overheating and if the chopper is removed far enough from the detector, the unit will not kick start.

Heat Dissipation

suteny0r writes[1]: "The problem with the original motor controller is heat dissipation. I burned out two before i figured it out. I'm ordering a new one from thequadgroup on ebay.

I plan to retrofit it with heatsinks on the output devices, possibly sink heat to the aluminum case, cut ventilation holes in the front and back of the deck, and possibly install a cooling fan (pc cpu style).

I'm also trying to recreate it using an arduino, from http://www.adafruit.com"
  1. http://www.motorboardmods.com/forum/viewtopic.php?f=3&t=2&p=299#p299