Sunday, December 21, 2014

RIP Flying Flowerpot

Pre Flight

The Flying Flowerpot has gone to the great beyond, aka the garbage bin.  It was a great first drone to build, I learned a lot, but it had its share of problems.

For the last flight, I programmed it via Mission Planner to fly a rough polyhedron at 60 feet over the River Mills Park near the Potomac River.  It accomplished this and then loitered.  When I switched it back to Stabilize mode, it somehow became unstable and did a death dive.  This broke the internal frame, two arms, two propellers, one motor, the battery mount, and the flower pot.   The basic electronics are fine, but I will have to get a new frame kit and motor at least.  The video is below.

The new build will take some time, so postings may be sporadic.  Have a Merry Christmas and a Happy New Year and Happy Hannukah.

Thursday, December 18, 2014

Спасибі читачів Danke Leser Thank You Readers

Привіт моїм читачам в Україні та Різдвом. Спасибі за читання мого блогу. Я бажаю вам успіху в новому році.

Hallo, meine Leser in Deutschland und frohe Weihnachten. Danke für das Lesen meines Blogs. Ich wünsche Ihnen viel Glück im neuen Jahr.

Hello to my readers in USA, Canada, UK and Merry Christmas.  Thank you for reading my Quadcopter blog.  I wish you good luck in the new year.

The most avid readers of my blog are in the Ukraine, followed by the US, Canada, and Germany.

Wednesday, December 17, 2014

Flying Flowerpot 2.0 -- SK450 Quadcopter Rebuilt

Flying Flowerpot 2.0

I finished the Flying Flowerpot quadcopter rebuild and had a successful basement test flight in the new configuration.  Changes since the last blog posting:

  1. Moved the camera mount again, to the upper level but with a new mounting bracket so the camera is out front between the props.
  2. Moved the receiver slightly.
  3. Tidied up the wires.
The following photos show the Flying Flowerpot 2.0:
Top view, no flower pot
Note the receiver attached to top level with double sided foam tape
New camera mount
Front view
Rear View

Tuesday, December 16, 2014

Rebuilding The Flying Flower Pot Quadcopter - The Six Million Dollar Man

Partially Rebuilt Flying Flower Pot (Pot removed for clarity)
One of the advantages of building your own quadcopter is that you know how to fix it if it breaks, and you can make improvements at the same time.  It is kind of like the Six Million Dollar Man TV series:   "We can rebuild him. We have the technology. We can make him better than he was. Better, stronger, faster."  The Flowering Flowerpot, after its last flight and crash (see previous blog post), needs this treatment.

First, I got rid of the battery monitoring module, which might be causing problems and I cannot figure out how to use it.

Second, I rewired the control module (APM) to receiver wiring to get rid of the servo extension cables and labeling.
Rewiring, receiver is on the left
Third, I repaired the damage to the quadcopter - a broken arm and a broken motor mount on the end of another arm using 5 minute epoxy, which smells like crap and gets everywhere.

Broken motor mount

Break in arm
Fourth, I got rid of the structure holding the GPS and compass and mounted them using nylon standoffs on the third level.
GPS remounted
Fifth, I removed the long landing gear and mounted the camera on top.  The long landing gear seem to cause a lot of damage in crashes.
camera mount
I also ordered a bunch of spare parts (arms, motor mounts, landing gear..).  Stay tuned for more updates as we get the Pot ready for its next adventure.

Monday, December 15, 2014

The Flying Flowerpot Flies and Crashes Again

Make Sure Everything is Tightened

Had a crash yesterday with some damage.  Nothing serious and I was able to repair it quickly.  The "Flying Flower Pot" seems quite robust.  The problem was a propeller that came loose, causing the quadcopter to fall from about 20 feet to the pavement.  I then checked all the bolts and screws and found a few that were getting loose due to the vibration, so check your quad before every flying session.

Friday, December 12, 2014

Storing LiPo Batteries

I am still coming up to speed on usng LiPo batteries in models.  The latest thing I learned is that you should not store the batteries fully charged, or let them fully discharge.  The prevailing wisdom is that you should store them at 3.85 volts per cell, or 11.55 volts for the 3 cell packs that I am using.

I don't have a fancy charger yet so I was not sure how to get them down to 11.55 volts.  Luckily I remembered enough of my old Circuits class and am enough of a pack rat that I could create my own discharge circuit.

Using an old 50 watt 7.5 ohm resistor, a homemade heatsink for the resistor, some wire, and my newly purchased XT60 connectors, I was able to solder together a discharge circuit.

              + ------------ resistor
 XT60                             /
              - -------------------/

I monitor the voltage with a voltmeter and was able to discharge my packs to 11.55 volts and then store them in a LiPo protective bag (good precaution) on the concrete floor in the basement away from combustible material.  Always stay close to and monitor your batteries continuously when charging or discharging them.

Note that LiPo batteries can be dangerous and you should follow ALL manufacturers' warnings on the use, storage, and charging of these batteries.  I am not an expert and you should check the Internet and the manufacturer of your batteries and charger for accurate information.

Wednesday, December 10, 2014

Review: UDI 818A Quadcopter

UDI 818A as it comes out of the box

This mid size low cost intermediate grade quadcopter is easy to fly and includes a camera.  It is a good trainer before moving on to more complicated and expensive machines.  The unit is fully assembled and you just have to charge the flight batteries, insert transmitter batteries, and then you are ready to go.

The UDI 818A is available from Amazon and others for about $65 to $85 US.  This includes the copter with camera, transmitter (mode 2), extra battery, USB charger, and extra props.  It comes in white (my unit) or black, they are identical except for the color.  All you need to add are AA batteries for the transmitter.


The unit incorporates a horizontal plastic prop guard assembly to help preserve the copter when you bump into something.  You can hit an obstruction without damaging the quadcopter.  You can turn the camera on and off with the transmitter and it takes decent video (see the youtube link below). Other than that, it is a pretty standard 4 channel quadcopter with 6 axis gyro stabilization.

Documentation is terrible - a google translation from Chinese with some made-up words thrown in.  Read it to get some basic ideas and a good laugh.


Relatively easy to fly, the throttle is not too sensitive and the controls work well.  Flight time is about 7 mins on one battery and it takes about 1 to 2 hours to recharge.  The inevitable crashes do not seem to mar walls or ceilings, in case your wife or mother is wondering.

This can be flown outdoors if it is fairly calm, but be careful as it will be harder to control than in controlled indoor environment.


There are no accessories and you cannot add any due to the small size of the unit.  You may want to buy extra batteries or props that can be found on Amazon or Ebay.

Monday, December 8, 2014

Some Tips from the Meetup

I learned a few things at the Meetup that I will pass along.

  • Flying with larger propellers will make your video smoother but make the quadcopter less maneuverable.  I have 10 inch props on my homebuilt but I could go to 12 inches.
  • You cannot assign a separate channel to the AUTO function on your APM which triggers an autonomous mission.  AUTO is just a flight mode so it must be controlled by the same channel that allows you to use Stabilize or Loiter.  That was one of my questions that I got answered.
  • There is a capability called "OpenTX" that allows you to program inexpensive radios to do almost anything.  The radio is the 9X which is available branded Turnigy, Flysky, etc. and costs $50 or so.  You can also add a board inside the transmitter to allow USB hookup, it is from Smartieparts and cost about $20.
  • You can get plans to print a quadcopter frame using a 3D printer.

Sunday, December 7, 2014

DC Area Drone User Group Meetup

I went to a "Meetup" of the DC Area Drone User Group yesterday.  It is essentially an informal meeting of like-minded individuals organized through the Meetup application.

The meeting was very useful as we had a great mix of beginners like me, experienced folks, large drones, small drones, different radio setups, etc.  I was able to ask questions of some of the experienced folks about how to set up my controller and radio, what props to use, where to buy parts, etc.  There was also an opportunity to see what other people had done with their drones - construction techniques, equipment, and so on.  You also get to meet people and exchange contact information.

If your community has a similar club or users group, I encourage you to attend as it is a great way to meet folks, get questions answered, and learn.

Tuesday, December 2, 2014

Mission Planner, Google Earth, and Logs

A plot of a drone flight over my house

I am starting to play with the Mission Planner software which allows you to program your drone-quadcopter, read logs, and program autonomous "missions".  One of the interesting aspects is the ability to download logs from the flight controller and plot your flight paths on google earth.  Mission planner outputs a KMZ file which can be read by Google Earth and viewed in the application.  The roller-coaster-like plot in red above shows my flight of November 29th over my house.  The video from the onboard camera was posted in a previous blog entry.  You can see the takeoff from the driveway, flight over the house, then back climbing, then doubling back, followed by a collision with the roof and a crash landing in the bushes.

Evaluation of Homebuilt Quadcopter Components

I put together a table with my evaluation of the components I used to build the quadcopter and the rough cost of the quadcopter: $320.

PartSourceRating (1=best)Approx costComments
Hobbyking SK450 Glass Fiber Quadcopter Frame 450mmHobbyking1$20.00Well documented, rugged
TURNIGY Plush 25amp Speed ControllerHobbyking1$13.00Well documented, works well, does not overheat, used 4
Turnigy Multistar 2216-800Kv 14Pole Multi-Rotor OutrunnerHobbyking1$16.00Works well, used 4 units
Hobby King Quadcopter Power Distribution BoardHobbyking2$5.00Works well but hard to mount
Extended Landing Skid Set for SK450 Quadcopter FrameHobbyking2$11.00Works but a bit too flexible
Slow Fly Electric Prop 1045R SFHobbyking3$3.00Works, inexpensive, but prone to breakage
TURNIGY BESC Programming CardHobbyking1$5.00Well documented, works well
Turnigy 2200mAh 3S 20C Lipo PackHobbyking1$10.00Good power delivery, good value
OrangeRx R615X DSM2/DSMX Compatible 6Ch 2.4GHz Receiver w/CPPMHobbyking1$10.00Works well, good value, compatible with Spektrum DX4i Transmitter
HobbyKing HKPilot Mega Mini Combo Flight Controller GPS and Power ModuleHobbyking4$120.00Flimsy USB, poor documentation
5" (inch) Travel Micro USB Cable, Twin Pack CablesAmazon1$10.00Great way to protect USB on APM
Hobbypower Top Pin APM2.6 External Compass APM Flight Controller w/ UBLOX NEO-6M GPSAmazon2$70.00Works great, great value, no documentation
Tenergy 1-4 Cells Li-PO/Li-Fe Balance Airsoft Battery ChargerAmazon1$20.00works great, great value
2 of NEEWER® 3.5mm Gold Plated Bullet Banana Plug Connector for RC Battery 10-PairsAmazon1$7.00Works well, used 2 packs
Dowels, screws, glue, velcro, flower potHome Depot1$25.00Cheaper than hobby store
Total cost of built unit (not including broken Hobbyking Controller)$319.00

Monday, December 1, 2014

Flying The Quadcopter

The Quadcopter is flying well.

Yesterday I had some successful flights (see video above) but one crash landing that required some repairs - nothing major - a couple of new propellers and reattaching the GPS mount with glue.

Today I had some great flights in a park by the river with fabulous panoramic views under clear blue skies with little wind, but the camera stopped working so there is no footage.  I also tried the althold and loiter functions and they worked like a charm.

I am getting about 10 minutes of flying time with a 2200mah battery pack and I have ordered a 3000mah pack as a spare.  They take a while to recharge (a few hours).