Sunday, April 26, 2015

FPV begins

I hear that once you learn to fly with "first person video" (FPV) it's hard to go back. This weekend hasn't been great weather so new, more powerful motors were fitted and also a 200mW transmitter and camera was added.

The little camera and transmitter is great and runs on a power rail from 5-28V so very easy to hook up - I just ran the tiny wires to spare contacts under the main power distribution board. What could possibly go wrong?

There was a break in the rain so I headed for the local football field.

I took off, hovered (fighting the wind), and landed watching only via the headset video. Scary but seemed ok. A second flight didn't go so well, a propellor came off and the craft landed heavily and then appeared to catch on fire! Seems like the wiring for the camera power had shorted and was burning the carbon fibre frame.

Great fun.

Saturday, April 18, 2015

Some flights at the football field in calm conditions

Woke early this morning and noticed a complete lack of wind so off to the local park. Here's a few videos. The goal posts are a natural target.

I'm still a very conservative flyer but speed is increasing over time.

Practicing going up high - and landing again. The view isn't great here but it's nice to get way over the trees.

Friday, April 17, 2015

Great way to run the Hubsan battery connector

Saw this excellent idea on the Reddit multi rotor forum.

Running the wires over the top helps avoid the battery slipping out. It doesn't work with some third party batteries but you can run over one of the legs at least.

Friday, April 10, 2015

Hubsan H107D FPV Micro Drone

This is a fun toy.

While it certainly flies well, the transmitter eats batteries rather quickly. The video, recorded on the transmitter has a weird aspect ratio and seems to be non-standard.

I'm finding it hard to fly via video only as the range of view is rather narrow.

Sunday, April 5, 2015

Restoring an over-discharged LiPo cell

I over discharged a LiPo 3 cell battery pack such that one cell, the middle one, read just 0.6V and neither of my chargers would charge the pack.

This is not a new problem and rather than just give up, it seems that if you're careful you can trickle charge the low cell to bring it up to a reasonable voltage for a smart charger to take over. The advice I found suggested charging at 100mA so I put a 120 ohm resistor in series with a 12V supply, put a volt meter across the cell and watched it slowly rise.

Normal voltage for a cell is 3.7 volts but I let the slow charging bring the cell up to 3.5V and now my normal charger is doing the rest.

Saturday, April 4, 2015

Morning flight at the local park

The easter rain has stopped this morning so I fitted a camera and headed off to the local park with my new drone. It's a little windy and I have poor flying skills but here's how it looked.

The video probably looks much better if you click through to YouTube and view in HD. Here's the craft with camera held on with velcro.

After a slightly heavy landing the only damage is a missing propeller tip.

Choosing and ordering parts

There's lots to learn about building multi-rotor craft. I'm particularly interested in the 250mm (motor to motor space) size as they are reasonably portable, yet able to carry a camera and not to scary.

Oscarliang has a great run down of parts alternatives.

So far I've been ordering from Banggood, Aliexpress, Hobbyking and ebay.

Friday, April 3, 2015

Building a 250mm drone

A few steps up from the micro-drones are the 250mm class drones. Right now I'm building one from parts and using the KK2.1 control board. It's coming together quite nicely after several false starts.

There's plenty of space up front for a camera on top and transmitter below.

It's been raining pretty steadily this easter weekend but I gave it go anyway.

Formation flying

A demonstration of precision formation flying.

Ground effect, and ceiling effect may have had an effect...

The much loved Hubsan X4

The Hubsan X4 is a well regarded micro-drone with amazing stability when new.

Photo by Hubsan

These are the gateway drug to the world of multi-rotor craft and if you look around Hubsan's site you'll see where all this is going. They fly well in large spaces.

Or in a home or office space.

After a few crashes the propellors need to be replaced, spares are available. The other thing that goes pretty quickly are motors which either become stiff or die all together. Good news is that it is possible to replace them with some fine soldering.

Each battery only lasts about 6 minutes so you'll want to get extras and there are multi-chargers available. All charge from a USB 5V port.

Micro-drone with video camera

This UFO micro-drone cost $50 from the market and comes with a built in still and video camera.

The motors and battery are larger than those of the Hubsan X4 or the Top Selling X6 presumably to lift the extra weight of the camera. Shown above are after market three element props which I do not recommend.

The video records to a micro-SD card in motion Jpeg format and it's very poor unless you use a Class 10 card which has enough I/O speed. Here's some sample video, you might want to turn the volume down before hitting play.

This has been a fun drone and the remote has buttons for taking photos, starting and stopping video and for turning on a light.

Love the "High AGILIY" control.

Here's the box: