Replacement MM450 E-gyro ESC

Situation: Maybe your old e-gyro esc burned out, you own a vmx450 and want an e-gyro upgrade kit, or you just purchased a new MM450 without an e-gyro esc.

The MM450 and E-gyro upgrade kit used to include a 30A esc. Unfortunately that apparently had issues in manufacturing and so was pulled from the bike and kit. The status of the original gyro esc is unknown. Atomik is now selling the bike (and e-gyro kit) without a gyro esc for the time being. On the website for the bike, under “Required Items” it lists “50A Brushless ESC for eGyro.” They have a tech sheet with information on what sort of esc you can buy, which is basically a plane/heli esc with soft startup feature. You can view the PDF “MM450 Without Gyro Instructions” under the documents tab at http://www.atomik-rc.com/Metal-Mulisha-Brian-Deegan-MM450-RC-Dirtbike-ARR_2.html?sc=31&category=76730
(NOTE: Its not clear why Atomik changed the Amps on the ESC requirements from 30 to 50, but owners of 30A ESC’s have reported no issues. So if you can find a cheaper 30A ESC with same soft start ramp up, its up to you but worth considering.)

The big difference between the original gyro esc and buying a plane/heli esc is that the original had a built in ramp-up of the gyro to full speed so no other signal was required to fire that up. As far as I know, a regular plane/heli esc can’t do that by itself so it requires either a servo tester, or use 3rd or 4th channel on receiver and a radio to start the gyro ramping up. If you only have a 3ch radio and want to install a front brake kit that uses ch3, then a servo tester is your only option. If you have a 4ch system, then you can still run the front brake on ch3 and control the e-gyro on ch4. Your radio will have to support this sort of channel control, which is mentioned in the tech sheet if you follow link.

Find a no frils, small, simple tester which should only cost about $10. Here are some options for servo testers to look for that should work:
ESKY Rc Hobby Servo Tester
Hobbyking Simple Servo Tester

Wiring of E-gyro ESC:
– 3 wires out: connect to the e-gyro stator motor with 3.5mm bullet connectors
– 2 wires in: for pos/neg power use 3.5 bullet connectors. If not already setup (you have a VMX), you will need to soldier outgoing pos/neg wires from your power source, like the main bike ESC pos/neg with same 3.5 bullets that will connect to the gyro esc power wires.
– 3 pin connector: either plugs into your main radio receiver, ch3 or ch4, or into the servo tester for control signal.

Wiring of Servo Tester:
– Power in: hard to say what design you get but the servo tester will have either a small 3 pin design for power or actual pos/neg wires option so you need to bring power in to give servo tester power.
– 3 pin Signal Out: you will connect the gyro esc 3 pin receiver connector into the servo tester. This sends out the proper signal from tester to the gyro esc, which tells the gyro motor to start spinning!

Final Check: gyro flywheel should spin the same direction as the rear wheel to go forward. If gyro is spinning wrong direction switch up 2 of the 3 wires going from gyro esc to the gyro stator. Hope this helps.

Photos by: Mitch Landry and David Hourston. Thanks guys!

8 comments

  1. Que buen articulo, me sirvió muchísimo. Amigo yo tengo un control DX3C pero no lo he podido configurar bien; usted me podría guiar en eso. Muchas gracias.
    Desde Colombia John Bermudez

  2. I think my egyro ESC is not working. Sometimes it will spool up, other times it starts but nothing happens. I opened up the wheel and it looked fine, and there is a green light on the egyro ESC but it does not work. I have a couple questions on your fix:
    I do not understand how you are wiring the servo tester? Can you use the stock TX or will this only work with an aftermarket? How do you setup this channel on the atomik TX?

    Have you heard of anyone making the ESC? It would seem like the company would make the spare parts out of China, has anyone contacted them?

    Thanks for keeping this up, I like the dirt bike alot and have used your tips to rebuild my front shocks, and replace the rear.

    Thanks!

    Bill

  3. Bill,
    Not sure how I can help with your esc. Its possible for the motor wires coming out of the wheel on right side at the outer bearing if the wire covering got worn off.

    I listed an alternative to using a separate gyro esc, which is a servo tester. What this little box does is send a signal to your gyro motor to spool up. Turning the dial tells the motor how fast to spin. It’s like having a separate manual receiver just for egyro so you do not setup with your bike tx. Instead of a programmed receiver that spools up the gyro automatically, the servo tester requires you to manually dial up to spool gyro motor.

    Sorry for late response.

  4. I have just purchased one of these bikes and have the second (gyro) esc connected to a “soft start” 40amp esc.
    I am unable to get both the gyro and the bike motor to run at the same time.
    I can easily do it with my heli TX (DX8) and a AR8000 on the gyro. When I connect everything together on the DX3R transmitter, I am unable to get both to operate.

    “Turning the dial tells the motor how fast to spin. It’s like having a separate manual receiver just for egyro so you do not setup with your bike tx.”

    So you must have the servo tester to run the gyro ?
    I cant just conect the two esc’s together ??

  5. There are two options for how the e-gyro is controlled. Either you have the e-gyro esc connected and controlled to a servo testor, or you connect the e-gyro esc to 3rd or 4th channel on your receiver on the bike. Make sure the e-gyro esc is programmed with soft start. If you have egyro esc on 3rd channel, then maybe if you have the aux channel that is what you manipulate to speed it up.

  6. Thanks John for such a rapid reply.
    Sorry its taking this long for me ….

    I am using a Spektrum SR301 – sport surface Rx.
    It has 4 ports.

    Aux
    Thr
    Str
    Bind

    I have the bike esc plugged into the Thr. port. The Egyro plugged into the Aux port. I only get the rear tire to spin. Not the gyro. But the gyro does work. If I independently connect the gyro I can get it to wind up.

    Is this Receiver , the SR301 good enough for this configuration ?

    Like I stated above, I have ordered the “ESKY Rc Hobby Servo Tester”, hoping that will solve it. But in the mean time I wanted to try and figure out why the Aux port doenst help .

    Thank you

  7. I don’t see why your specktrum rx would not work. Your gyro esc should be programmed with soft start. So, on your specktrum, can you manipulate the EPA end points for AUX? I don’t have any experience with that radio, only the original stock Atomik radio. I have 2 links to what others were trying to figure out how to get the gyro esc working off the 3rd channel esc. Below are some individual posts about setting up e-gyro that might give you ideas on what to try on your radio. They are from the Atomik MM450 RCGROUP Discussion thread
    http://www.rcgroups.com/forums/showpost.php?p=25681269&postcount=3667
    http://www.rcgroups.com/forums/showpost.php?p=29721851&postcount=5745

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