Vortex 230 FPV Flight

I finally got a chance to make an FPV flight with my quad copter today in an open field.

Here is a video from the DVR:

Video Link

New Power Cable in the Sabre

The setup for the Sabre has always been that the BEC was powered by the flight battery's balance plug. I’ve never had any issues, however, after a friend brought it to my attention, I decided to do some investigation regarding the current draw of my servos on the Sabre.

The concern is that the balance plugs (JST-XH) are rated for low current (2 or 3 Amps, according to the internet) and if my setup is drawing more than that, then eventually something in the connector could heat up enough to cause a failure, resulting in loss of power to the servos, and therefore loss of control of the airplane.

I hooked up my ammeter in series with the BEC and powered the airplane on. At idle (that is, all servos powered but not moving (representative of straight and level flight in smooth air)), it pulled about 1.8A. Cycling the sticks while deploying flaps would pull 5 – 6A, and cycling the sticks while loading servos could spike to 8 – 9A. Granted, this is worst case scenario, and it is only for short periods of time, but this was enough to make me uncomfortable with keeping the balance plug as the input power source for the BEC.

For my reassurance, I built a new power cable that powers the plane (through the Vector’s Power Supply Unit (PSU)), as well as a second set of wires which will power the BEC. The micro Deans connector is what will plug into the BEC now, and these connectors are rated for 10A continuous. With this upgrade, the entire airplane will be powered just by plugging in the flight battery’s Deans plug into this adapter, but I will still be able to power just the BEC for servo checks, just by unplugging the Deans from the PSU.

The New Cable. (The small connector is what is new, compared to the old one)

New (Top) vs. Old (Bottom) Connector

Sabre Weight Analysis & Ballast

Since I first measured the components and parts of the Sabre, it has gone through so many iterations of small changes that I can't quite capture everything.

I finally got around to the tedious task of re-measuring all of the components, as well as the important (and previously not done) task of laterally balancing the wing.

Since the 1.3 GHz video transmitter is so much heavier out on the wing when compared to the 5.8 GHz one I was using, the lateral imbalance was enough to warrant correcting it. I did this by adding coins to it until it balanced, and then carving out a clean hole in the left wingtip to hide the weights away.

I actually made up a process for making the opening, at the right size and depth. I started by tracing the outline of the weights. Then I measured the depth I needed for the set of coins to be flush or slightly submerged under the surface of the wing. I put a wrap of tape on the Exacto at this depth, and cut a grid out of the foam inside the outline of the desired opening. Then I used needle-nosed pliers to pluck each piece of foam out of the grid. This process worked really well, and I will likely find applications for it in the future. For the cover of the weights, I simply used a piece of white card stock and packaging tape.

I also had to make a tail weight for use with flights that use the heavier 16,000 mAh battery. This weight is also made with tape and coins, but it is not as elegant as the wingtip weight. I'll just insert it into the hole in the aft part of the fuselage where the tail pieces attach, and secure it with tape when it is to be used.

I created a matrix of the airplane configurations that are possible, or at least probable with all of my current equipment, and used this to calculate the flight weights.

Overall, the plane is about 7.6 - 8.5 lbs with a 5.8 GHz FPV setup, and 7.7 - 8.7 lbs with a 1.3 GHz setup.

GoPro Hero5 Session

I've been using my Mobius ActionCam HD for all of my HD recording on my planes (and rockets) for many years.

Since the GoPro Hero6 came out, the price on the 5's dropped substantially, and I decided to get one. I bought the GoPro Hero5 Session, which is the smaller, cube-shaped version of their cameras. I'll be able to use this on the pan/tilt setup on the Sabre, as well as directly on the Vortex 230 Mojo quad.

I'm looking forward to actually getting some footage on it.

1.3 GHz Ground Station Initial Setup

2/15/18: See updated schematic here.

Today I mounted all the equipment onto the back of the Crosshair antenna. My plan is to use the Crosshair as the base, because it attaches directly to the tripod. With all the gear attached to the back of the Crosshair on the tripod, it is easy to make setup changes, such as changing the video receiver antennas.

The idea is that if I am flying far, I'll manually aim the Crosshair (the tripod) in the direction of the flight, and swap back to the Airblade for flying around in closer.

This is what is wired up on the back of the tripod now.

The Setup without the Battery

With the Battery

Mounted on the Tripod

Front View

New 1.3 GHz Video Antennas

I received my omni-directional antennas for the Sabre and for the ground station. I got a pair of the IBcrazy Airblades, as well as a TrueRC Singularity. The Airblades are both for the receiving end, as well as the video transmitting side (on the plane). The Singularity is to try in place of the Airblade on the plane, because it has a much smaller form.

The pair of Airblades

Singularity (Left), vs. Airblade (Right)

Ground Station Progress & Updated Schematics

I made some minimal progress on my ground station. I got a tripod to mount things to as well as the 1.3 GHz Crosshair video receiver antenna.

Those are both shown here:

Pardon the mess! This is what the reality of working with
this much stuff in a one bedroom apartment looks like.

In doing more reading and learning, as well as taking suggestions from people on RCGroups, I also modified my ground station plan. Rather than have all the gear on the single tripod, powered by one battery, I have separated out the control portion of the repeater from the video portion. This physical separation will be the simplest way to ensure my UHF signal doesn't cause video issues. It also means that the way I have my control repeater set up now can still be used as-is. That schematic is here:

UHF Control Repeater Schematic

Here is the updated ground station schematic.

Video Receiver Schematic. This is exactly what will be 
on the ground station when it is done in its simplest form