By Steve B.
Last year I bought the Avanti S from MotionRC.com. Although this is an excellent jet, I wanted it to go faster. The modification required replacing the entire fan assembly, the motor and the speed control. It was all pretty simple to do because al the new parts fit right in where the old ones were. No foam cutting, just a slight change to the ESC mount.
The test flights went perfectly. It is significantly faster than the stock setup. The flights are shorter due to the higher currents. Unfortunately, I forgot to get video.
In order to get the correct motor and fan, I took the easy route and went to our very own ‘motor master’, Steve Neu of Neutronics and asked him. If anyone knows how to make airplanes go fast. . . well, you’ve seen him fly, enough said. Steve created a special wind motor just for this application: NeuMotor inrunner 1412/2D/S/5mm with a Kv of 2400. In this application the motor is using 2700 Watts. The stock motor’s Kv was 1900.
The stock fan that comes with the Avanti is plastic and specially made to mount on their outrunner motor that itself mounts from the rear. The motor and fan are cantilevered off the back of the motor. Seems crazy but it works. This fan cannot accept a motor that mounts from the front. Turns out they have fan housing made of metal and it fits a front mounting inrunner (p/n P0806). I used the fan housing but the fan that comes with it cannot mount to a standard motor shaft. So I purchased a Jetfan 80 V3 from eJets in France. It is made to fit the NeuMotor 5mm shaft.
I bought a Castle Phoenix Edge 130Amp ESC to replace the stock 100 Amp ESC. Current at full throttle is 135Amps. The battery is the stock 6S 5000mAh Li-Po.
I’ll take you through a pictorial explanation of the conversion process:
Below you can see how I took off the motor hatch. The screw eyes made it easy to lift it off (after you remove the screws). Otherwise it is a pain.
Here is the stock setup.
Four small screws removes the stock fan.
The new ESC does not fit. The plywood mount needs to be modified.
Cut the mount at the two lines opening it up to the front.
I used a Dremel with a small cutting bit to make the cuts.
The first cut.
The piece removed. Now the Castle ESC can slide in from the front.
The ESC tray viewed from under the canopy.
The ESC sliding in.
The ESC in place. It fits perfectly in this position. Just add screws.
Connectors were added to the motor wires from the ESC. The wires were cut at different lengths so the connectors would not all be side-by-side.
The power setup. I use a separate Castle BEC instead of the one on the ESC. If the ESC fries then so does its BEC and the plane crashes.
Effux RC has upgraded the power in the Avanti and L-39. See their videos: