A practical approach to RC planes

MiniTri Build – Part 2

MiniTri Build Begins!

MiniTri Build Begins!

A few weeks ago I but together a prototype frame kit from Nick Caldwell. This week I finally got all the electronics in and started the build. In today’s post I’ll run through some of the main points of the build, give a parts list, and give a bit of my reaction to the new kit. So let’s get started.

MinTri Frame from Nick Caldwell

MinTri Frame from Nick Caldwell

The new frame kit from Nick is a rock solid build platform. It’s everything you want in a mini multiroter: stiff, well designed, and still plenty of room even for the small size.

From my experience with my Blackout Mini H Quad I had a pretty good idea of what components to string together to build a super fast and agile FPV multirotor. I started with 3 killer Cobra CM-2208/20 motors. These 2000 kv motors will easily spin a 6×4 prop on a 3-cell at under 12 amps. This wicked combination should result in 50-65 mph speeds and easily 10-12 minute flight times.

3 Pole Motor / ESC Connector

3 Pole Motor / ESC Connector

I also took this opportunity to checking out these new 3 Pole Motor / ESC Connectors from HK. They allow for easy connect/disconnect of the motor and esc. They also help clean up the build. The only downside is you have to be absolutely sure of your connections before soldering. If the poles are backwards and your motor runs in the opposite direction than intended you’ll be de-soldering and starting again. Otherwise I love the clean look of these connectors. I will defiantly be thinking of adding them to future builds.

For ESC’s I used three 20 amp Afro ESC‘s also from HK. They are probably a bit overkill but I had them just sitting in the shop. These run the SimonK Firmware and should be efficient and with the high clock speed they’ll have great throttle reaction time.

BackyardRC Tilt Motor Mount Version 1

BackyardRC Tilt Motor Mount Version 1

After mounting up the front two motors I turned to the tilt mechanism and rear motor mount. The original BackyardRC Tri Tilt Motor Mount was great and it has gained some traction over on thingiverse and elsewhere a like. At the time of this post it has been viewed nearly 3000 time, downloaded 325, and had two other members print and share!! But truth be told it had some limitations. The largest being that it required additional nose gear mounts to be modified to create the tilt action mechanism.

Evolution of BackyardRC's Tri Tilt Motor Mount

Evolution of BackyardRC’s Tri Tilt Motor Mount

So this felt like an prefect time to do a little redesign to make a self-contained all-in-one printable mount. After a few hours working in solidworks I came up with the BackyardRC MiniTri Motor Mount.

BackyardRC MiniTri Motor Mount

BackyardRC MiniTri Motor Mount

Made completely on the same principles of the original but with a ton of new enhancements. Optimized motors with a 16mm/18mm bolt pattern any of your most common and favorite motors will bolt right up. The main tilt shaft is a #10 by 30mm bolt (1.25 inches) found at any hardware store. Printed in solid ABS plastic it is rock solid. Easily mounts to any 1/2 boom with three zip ties. It also uses the trusty and powerful BMS-385DMAX Digital Servo with metal gears. I’ve been using this servo with my large tricopter spinning 10×3.5 props on 900kv NTM motors and never had a problem. It should handle the little 6×3 props with ease.

While the focus of my redesign was around the MiniTri I’ll be designing top plates for all sizes and bolt hole patterns shortly. But more on that on another day.

Atom CC3D

Atom CC3D

Moving on from the motors I decided to stay in the spirit of mini things and picked up the new Atom CC3D flight controller from I’ve been running the standard CC3D on my mini H quad and it is awesome! This will be the first build I try out the Atom but as the site claims it is all same functionality in the footprint of less than 1/2 of it’s bigger brother. I finished up the day by mounting the go-pro case on the top and mocking up where the FPV gear will mount.

MiniTri is almost Done!!

MiniTri is almost Done!!

Overall the build is coming along well. Nick’s frame kit has proved to be a solid foundation for a sleek clean build. I can’t wait to get this little guy tuned and in the air. I really hope Nick takes this kit beyond the prototype phase and releases it to the masses because it is a thing of beauty!

MiniTri Goodness

MiniTri Goodness

Only a few steps remain before I start some early test flights. With any luck I will find 2-3 hours tomorrow and finish up the build!! Then it’s time to go flying!!


Parts List:

MiniTri Frame Kit (x1)

Cobra CM-2208/20 2000 kv motors (x3)

3 Pole Motor / ESC Connector (x2)

Afro ESC 20Amp Multi-rotor Motor Speed Controller  (x3)

BMS-385DMAX Digital Servo (x1)

Atom CC3D Flight Controller (x1)

Gemfan 6×3 Propeller (x1 set)

ZIPPY Flightmax 2200mAh 3S1P 40C (x1)

RC Receiver of your choice (x1)

My FPV Setup:

Go-Pro 3+ Camera (x1)

Super Slim GoPro 3 A/V Cable (x1)

ImmersionRC 5.8Ghz Audio/Video Transmitter (x1)

ImmersionRC 5.8GHz Circular Polarized SpiroNet Antenna (x1 set)

SMA 90 Degree Antenna Adapter (x1)

Fatshark Goggles (x1)


One response to “MiniTri Build – Part 2

  1. Pingback: Nick’s 300mm Tricopter | flightbay

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