High Power MOSFET for Dizzy Space Plane

We already covered one way to increase the power of the carbon fiber Dizzy Space using new motors, but is there a way to ramp the power up further still? The answer to that question is yes thanks to a modification to the AeroAce receiver. This modification, created by Megabyte-2 of RCGROUPS, provides an enormous power boost by using two high power MOSFET chips.

Check out this video of how dramatically these high power MOSFET components change the flight characteristics of the Carbon Fiber Dizzy Space:

Here is a list of things you will need

  1. Your old AeroAce receiver board
  2. (2) IRLML6401 MOSFETS MOUSER
  3. (2) SMD 103 resistors (10K ohm)
  4. A fine tip soldiering iron and soldier
  5. Some adhesive, such as super glue (highly recommended)
  6. The guide Megabyte-2 created for both this modification and an actuator mod. You can download it here.

Disclaimer

Any modifications to your AeroAce receiver are at your own risk. Performing this modification is not for the faint of heart. The components you will be working with are EXTREMELY small making them easy to lose and easy to damage. If you choose to continue read on!

Getting Started

The first thing you should do is read over Megabyte-2’s document on performing the modification. The objective here is to replace the two motor driver transistors which currently supply power to the motors as shown in this schematic:

If you recall in our previous article about the high power motors, these two transistors can only put out and handle so much current.

Identifying the Motor Transistors on the Receiver Board

Spotting these two transistors can be challenging because almost all of the components on the board are “SMD” sized components which are very small.

Removing the existing Motor Transistors

The best way I have found to remove these transistors is to either “break” them using some diagonal cutters or try to click the two leads on the same side and then carefully de-soldier the chip’s remaining “anchor lead”.

Installing the new MOSFET drivers

To install each new MOSFET driver you face at least two challenges:

  1. How to keep the MOSFET in place while you soldier it.
  2. How to soldier the 103 resistor between the two pins on the one side of the chip as shown here.

Gluing the SMD 103 Resistor in place

The SMD 103 resistor should be placed where it needs to go and glued in between the two legs. Doing this is a bit tricky. These little SMD resistors stick to everything and are easily moved by glue, can be “wicked up” by the tip of a soldiering iron and, well, destroyed by just about everything.

Before you can glue each resistor in place, you need to test fit the little SMD resistor between the legs. Chances are, it will not fit because it is just slightly too big.

To solve this problem, carefully sand (or scrape with an exacto style knife) the inside of each leg so that the SMD resistor will fit in between. this area:

It will not take much scraping or sanding. Once the SMD resistor can fit between the legs its time to glue it in place.

The glue works best if you apply a small amount of adhesive to the side of the high power MOSFET as this arrow depicts.

You are also going to want to hold both parts “down” in place, because even applying super glue with a toothpick will cause both parts to jump about and move. What we found works best is to hold each component down at the locations shown here with two tooth picks being held by alligator clips in two “Help Hands”.

Gluing the MOSFET in place

After the glue has fully cured between the SMD resistor and high power MOSFET, we recommend applying a small amount of adhesive, such as UHU POR to the bottom of each MOSFET and then placing them on the Rx board with tweezers where they need to be. Allow the glue to cure. This should hold each high power MOSFET in place when you soldier it.

Soldiering

To soldier each of your assemblies in place take your time. Use a small amount of soldier and a fine tipped soldiering iron. Since everything is now glued its not going to shift on you. You just do not want to touch any of the other existing components with the soldiering iron! Once properly in place it should look something like this:

They don’t have to be perfect, just connected to the proper pads. Notice even ours twisted a bit during the installation process!

New High Power MOSFET Performance

The performance boost was great! The Carbon Fiber Dizzy Space jumped into the air and flew very high:

The craft felt more like flying a “full house” plane rather than a thrust vector one.

Turns were smooth and climb rate was incredible.

We hope you enjoyed this article. If you have not already done so, please check out our original Carbon Fiber Dizzy Space article. Stay tuned for our future article where we will be installing a “modern” 4 channel receiver and micro servos in the Carbon Fiber Dizzy Space.

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