Thursday, September 3, 2015

Eric Cheng's Cool Inspire Add-On

So Eric Cheng really is the coolest pilot in the world!  Look at the back of this Inspire, where he mounted a GoPro on a gimbal.  Eric writes:
DJI Inspire 1 flying aggressively at the beach with a Feiyu Tech FY-WG 3-Axis Wearable Gimbal for GoPro ( attached to the rear via curved GoPro mount. Shot with GoPro HERO4 Black. Footage taken during the documentary shoot with (Santa Cruz) Flight Club.

I might try this with my old no-name gimbal and see how it goes.

Eric mentions he got up to 55 MPH on this video.  Impressive!

blogodex = {"idx" : ["Inspire 1", "Gimbal", "Eric Cheng"]};

Tuesday, September 1, 2015

Modding an Apple Mac Power Supply, Part 2

 Now that we've got the Apple power supply running, we need to hook it up to the charger.  It turns out that standard 110V blades fit perfectly into the GND and 12V slots, so we just harvest a couple from an old wall wart.
Solder onto 12 gauge wire.  My charger has 4mm bullets, so I soldered that onto the other end of the wire.
 Shrink wrapped.  I measured how far the blades would go into the connector, and measured the shrink wrap accordingly.
 The fit is nice and tight.  I don't think it will slip out, but if it does that's safe since it will lose connection to the hot wires.
 I used a piece of bigger heat shrink to hold everything together.  Go onto ebay and you can buy a lifetime supply of various sized shrink tube for a couple of bucks. I think this was 10mm shrink tube.
 I tried fitting a switch in place of the paper clip.  I learned that you can't solder onto a paper clip!  The Internet reveals that they are typically plated with some sort of alloy (tin/nickel?) that isn't attractive to solder.

A couple of old male servo leads worked nicely, but was wobbly.  I might run this with a length of wire, and then attach the switch onto the charger.  Till then, it's a paperclip jammed into the connector, which somehow pleases me very much!

Out with the old, in with the new.  Goodbye old Dell power supply, and thanks for the years of faithful yet kinda ugly and a bit underpowered service you provided.

blogdex = {"toc" : "Power Supply"};

Sunday, August 30, 2015

Modding an Apple Mac Pro Power Supply

 I got an old Mac Pro power supply to replace my puny old Dell.  The thing is massive!  79A of 12V power, that's over 900 watts!!

But, there's a catch.  Like all things Apple, it's a beautifully crafted, high quality unit.  And unlike the rats-nest wiring associated with PC power supplies, it's got a single clean wiring harness which is sadly undocumented on the Internet.
 I guessed the large connectors would be for 12V and ground.  Measuring the voltages would indicate the polarity.  BUT  How to turn the unit on?  I was looking for the equivalent of the PC's Green PWR Wire, the one that if shorted out turns on the power supply.

Going strictly by guess, I started shorting out pairs of connections.  I figured it couldn't do much harm, since none of the wires would be carrying current if the PWR wire were not engaged.
Using a paper clip, I quickly found the pair of PWR,GND connection.  I'm not sure which one is which, but for my purposes it doesn't really matter.  I made a note of the connections so that I'll be able to recreate them when I cons up a connector to the charger.

The outside big connectors are both GND, and the inside big connectors are both +12.2V.  The PWR/GND pair is the outside small connectors, second from the bottom.  The connector is oriented so the left side is smooth, and the right side has the edge.
A slight bit of fiddling showed that the small curve of a paper clip was the perfect size to connect PWR/GND.  I snapped a picture of it and will cover it with tape to ensure it stays put.

That's it for the experiment phase.  I'll use the flat blades from an old extension cord to bodge up a connector for 4mm bullets which is what my power supply uses.  I'll update when I do that!

Here's a video walkthrough:

blogodex = {"toc" : "Power Supplies", "idx" : ["Mac", "charging", "power", "electronics"]};

Tuesday, August 11, 2015

Concord Model Engineers, August 11, 2015


Tuesday, August 11, 2015

CALL TO ORDER:  7:30 pm


Monthly meeting, Second Tuesday, 7:30 at Concord Airport Terminal.

Friday Fun Fly, Third Friday, 7:00 - 9:00 pm.
Gym at the Church of the Nazarene, 1650 Ashbury Dr., Concord

Fun Fly this month on Friday, Aug 21, Tenative, awaiting confirmation.


treasurer absent.




A quiet meeting, hoping all absent members are enjoying their Summer Vacation!

We will continue Indoor Fun Fly.  Cost to club is now $50, we will ask each attendee
to contribute $5.


Aug. 16, Masciano Control Line Contest. Alameda. Contact Jim,

Aug. 21-23, Jim Perrson (and others) will be running Tether Cars at the Good Guys West Coast Nationals.

Aug 29-30,

Aug 29-30, Control line speed contest, Napa.

Sept 5, Weigel Field, free flight contest.

Sept 13, Crows Landing, Former Naval Air Base, Flying Giants event, all day.

Sept. 26/27, Control Line Combat event at the Flying Electrons field.


Oakland Cloud Dusters.  1/2 Coupe, rubber powered, Ding Zarate 1st place;
.020 Gas, Jim Muether 1st place; OCD Cat, Lynn 4th place; P30 (13 entries), Lynn, 3rd place
3 max (90 sec) + P38.


1 Gal Sig 10% Nitro, Sig 1/2A Dewey Bird, Horizon Lipo Cell Voltage Checker,
Husky Screwdriver set, BHM Little Ike.


blogodex = {"toc" : "Concord Model Engineers"};

Sunday, July 26, 2015

Heat bent PVC

Andrew Newton has a nifty video showing how to use heat gun to construct things from PVC pipe.

You can get a flat piece of PVC for fabrication by cutting and splitting a ring and then heating it up with a heat gun.  I'm going to give this a try.

blogodex = {"idx" : ["PVC Construction"]};

Sunday, July 19, 2015

CME Minutes, June 2015

Walt Grant, RIP
Aeromodeller and Friend

Tuesday, June 9, 2015

CALL TO ORDER:  7:30 pm


Monthly meeting, Second Tuesday, 7:30 at Concord Airport Terminal.

Friday Fun Fly, Third Friday, 7:00 - 9:00 pm.
Gym at the Church of the Nazarene, 1650 Ashbury Dr., Concord

Fun Fly this month on Friday, June 19.


new balance  $2854.00




RIP, Walt Grant, long time CME Member.  There will be a small memorial service the 3rd week of July.  Walt was a great guy, and started aeromodelling in 1938. He and his brother both wanted to join the Army Air Corp, but their mother said she would only allow one of them to serve.  They flipped a coin and his brother won, and Walt ended up working at the Bendix plant in Philadelphia, which adjoined a large field perfect for flying. The club's thoughts and prayers go out to his wife Barbera and her family.

Onur Yildirim met Chuck last week.  Flying for about two months. Onur is an Electronics and Telecom Engineer.

Saturday, June 13, CME Picnic.  Start arriving around 10:00. Will eat about noon. Pot Luck.


June 20, Open air swap meet, 8:30 - noon, Alameda.  See attached.

July 25, SAM 27, Small Rubber Meet, Lakeville.  Need AMA insurance.




Ed Ringeu, Swoop DeVille, own design, P30, flat wing with with winglets, so easy to put together with no dihedral.  P30 has to fit in 30 inch box 40g chassis, 10g motor.  Ding Zarate wing design.

Ding Zarate, Jorback, John Odencamp design, E36 class.  Electric free flight. 150g.


Glue caddy, 15 min epoxy, roll yellow monokote, 1 gal 5% nitro, Radix 3D foam kit, BHM red flash 1/2A kit, Brodack Baby Clown kit


blogodex = {"toc" : "Concord Model Engineers"};

9xr Pro Taranis Gimbals

OpenRCForums user Myckey has a nice pair of posts on upgrading the 9xr Pro with Taranis gimbals.
I'm preparing to try it.  I'll make a video and take some pictures.  Prepping for that, here's the steps as I understand them.


The goal of this step is to modify the wiring so that the gimbal has two sets of three wires going into each 3-pin plug.  One set of wires is for the X axis and one set of wires is for the Y axis.

  • release the six gimbal wires from the multipin plug.
  • release the wires to both pairs of the 3-pin plugs.
  • attach each set of 3 wires from the gimbal to the 3-pin plugs.
When this step is completed, you have a 3-wire set for the X axis and a 3-wire set for the Y axis.


We need to modify each gimbal to fit in the 9xr gimbal hole.  Each of the four corners of the gimbal has an "ear" with two holes.  A bit of trimming will allow the Taranis gimbals to fit securely into the 9xr gimbal mounting plate.

  • sand or dremel the outside of the ear, removing the outside hole.  leave some material around the inside hole, as we will enlarge that.
  • open the case and remove the old gimbals. note that you will disconnect two wire harnesses for each gimbal.  leave the gimbal faceplace attached.
  • push the new gimbals to the faceplate so that the gimbal holes line up with the 9xr gimbal posts.  It's a friction fit.
  • check the alignment of the holes.  each gimbal hole should be about 1mm offset from the 9xr post.
  • turn the 9xr over and see if there's a gap between the gimbal and the faceplate.
  • if there's a gap, sand or dremel the gimbal around the mounting hole so that the gimbal will sit flush to the faceplate.
  • Enlarge the holes in the faceplate only using a 3mm or 1/8'' drill bit.  Drill from the top of the 9xr.
  • Attach the gimbal to the faceplate using a slightly longer screw (TBD: length?) of the same diameter (TBD: diameter?).
  • The gimbal should fit flush against the faceplate.

Inspect the fitting, attach the wires, test the harness connections,  and close up the case!
  • connect the shorter wire harness to the inner 9xr gimbal connection.
  • connect the longer wire harness to the outer 9xr gimbal connection.
  • attach a battery and test the gimbals as described in the next step.
  • close up the case.

Two things can go wrong with the wiring.  The X and Y axis can be swapped (i.e. moving the stick up and down shows motion in the horizontal direction), and the X and Y axes can be reversed (i.e. left stick motion show right motion in the radio).
  • go to the calibration menu.
  • if the X and Y axes are swapped, swap the two connectors.
  • if either the X or Y coordinates are reversed, swap the two outer wires of that connector.

Myckey's instructions are here.  A lot of people have wanted better 9xr gimbals, so a big shoutout to him for figuring this out in such a superb way!
blogodex = {"toc" : ["9xr Pro", "9xr"], "idx" : ["Taranis", "gimbals", "9xr gimbal upgrade"]};

Saturday, July 18, 2015

Nice Wireless Mini-Keyboard

Here's a nice mini-keyboard that I've gotten for my multimedia PC.  It's wireless, comes with a dongle, has a lipo battery, and charges with a mini-B USB connection.

It claims to have an autosleep mode.  I can confirm it works while plugged in to the charger.  I've tried it on Windows and Mac, and it seems to work pretty well.  I'll try it out with an Android OTG cable as well.

It's got a set of multimedia keys, which I'll try configuring with AutoHotKey.  Fn-Space sets the mouse sensitivity

It's about $11 on BangGood and listed as "2.4G Mini Wireless Keyboard Mouse with Touchpad for PC Android TV HTPC"

blogodex = {"idx" : "Mini Keyboard"};

Sunday, June 7, 2015

Tuesday, June 2, 2015

E-Flight 1S Battery Connectors

These are the connectors on E-Flight 1S batteries.

The official name is Molex PicoBlad;. It's often referred to as a Pico, UMX connector, or Micro JST.

I use these extension cables and cut them in half to get a pair of male/female connectors with pigtails.

blogodex = {"toc" : "Connector Mania", "idx" = ["Micro JST"]};

Saturday, May 30, 2015

SMA and RP-SMA Connectors

Be careful when connecting coax SMA connectors.  It's possible to physically hook up a pair of connectors that fit perfectly but have no connection for the center part of the cable.

Be sure and check if you're using SMA or RP-SMA (RP = reverse polarity) connectors when hooking things together.

Here's an adapter to switch between the two.

blogodex = {"toc" : "Connector Mania", "idx" : "SMA"};

Sunday, May 10, 2015

Some Good Deal on Amazon Batteries

Need some rechargables AA and AAA batteries?  These seem to be a good deal.  The Internet believes they're manufactured by Sanyo and are rebranded Enerloops.  Woo hoo!

AA 2000 mAh
AA 2400 mAh
AAA 850 mAh

And two chargers:

EBL 808 8 bay charger
EBL 807 4 bay charger

blogodex = {"idx" : ["power", "batteries"]};

Sunday, April 26, 2015

The Tao of Nutball

Saw this here... GoldGuy is the designer of the NutBall, and apparently a student of Philosophy!

On NutBall.

  • Don't add anything that's not absolutely required.
  • Build light and you will be rewarded.
  • The reason why the NutBall is super simple is to keep it light.
  • The difference between a high and low wing loading is either no joy or pure joy. 

On Weight.

  • Be happy, build light.
  • Light is might.
  • Weight is the enemy.
  • Only slopers add weight.
  • Light is a delight.
  • That's, as in ballast... Although my belt size has grown.
blogodex = {"idx" : ["NutBall", "GoldGuy", "Philosophy"]};

Tuesday, April 21, 2015

LED Spectator TV for FPV

RCGroups member UniversalRC shows his external video setup.  It runs on 12V and has a beefy tripod mount.  He uses it so his aerial video clients can watch the imagery he's capturing.

The monitor runs off of  4500 mAh 3S battery. Here's the tripod.

blogodex = {"idx" : ["FPV, "external monitor"]};

Saturday, April 18, 2015

Inspire 1 in the wind, two flavors of video

Upgraded the Inspire 1 firmware, everything went OK.  Took the unit out, and was impressed with its stability in the breeze.

I'm terrible at guessing wind speeds, but I'm pretty sure it was 15 mph gusting to 20 mph.  Can anyone guess the windspeed by the flags blowing?

I recorded the video at 4k, 60 mbits/sec, and transcoded a copy to 1080p, 30 mbits/sec.  I've included both... does it make a difference once it's uploaded to Youtube?

blogodex = {"idx" : ["Inspire 1", "video test", "flags", "wind"]};

Sunday, April 12, 2015

My Cheap Ikea Workbench

I was talking with a friend, and it turned out we both had workbenches made from Ikea tables!  Here's my setup, which is both small and pretty cheap.

ADILS legs (4) - $14 ($3.50 each).  It's hard to see from the website, but it includes screws and a mounting plate.  The plate screws onto the table top, and the leg screws into the mounting plate.

It comes in a couple of different colors and is 27.5 inches long, just right for a sit-down workspace.

LINNMON table top -  $6.  It's nice because the table top is the cheapest part.  When it gets too beat up, just run down and buy another!  It's pre-drilled to accept the ADILS mounting plate.

Everything goes together in just a couple of minutes.

blogodex = {"idx" : ["workshop", "workbench", "Ikea"]};

Thursday, April 9, 2015

DIY DJI Inspire 1 Battery "Charger"

"DIY" is one of the watchwords here at EastBay RC, so you can imagine it's going to be an interesting experience to deal with a real store-bought system like the Inspire 1.

Our first project: a power supply for charging the Inspire batteries.  Here's the prototype, which is working well.

The DJI power supply has these features: rated output of 26.3V, 3.83A (100W), proprietary connectors for battery and radio.
In order to get the 26.3V, I'm using a boost converter.  It will take input from 4V to 25V and convert it to 26.3V. I got it on Amazon for $12.  You can get it for about $8 if you don't mind waiting for China shipping.  Specs on my unit are

  • 9A max input, 6A max output.

Double check the ratings for the unit you get.
We'll go into more details in a followup post about how to configure the boost converter.  Here's my initial test connectors.  They are two prongs from an old extension cord, and fit perfectly into the battery.  Positive is on the left.  I'll do a video with some more construction details as well.
 Here's a second connector.  I glued the prongs onto a piece of scrap wood and insulted with liquid tape.  I double and tripled checked the polarity was correct.
Here's the final connector.  It works really well!

I can now charge the battery using any 12V-24V power supply, including my regular charger on Pb mode.  Charging from the car should be OK as well, but I'll double check the amperage requirements.

Anyways, hope this quick note helped, and if you're interested in seeing more DIY Inspire projects let me know!

Power Equivalence.  The table below shows the required amperage at several voltage levels in order to provide the equivalent power.  The first amps column is the straight calculated equivalent, and the second amps2 column take into account the approximate 10% power loss from the boost converter.

Watts Voltage  Amps Amps2
100      26.3  3.83
100      24    3.3    4.5
100      20    5.0    5.5
100      18    5.5    6.1
100      12    8.3    9.1

Note that the 12V amperage is just barely within the maximum amperage specified for my unit, mentioned above.

If you have a standard RC 4-button charger, you can set it to Pb (lead-acid), 20V, 5A and be just a little shy of the maximum equivalent charging capacity.

There's a rumor that the built-in charger of the smart battery won't current-limit. Sadly, too much of the DJI world runs on superstition, so until a battery dies and we get to do an autopsy, we won't be able to determine if this is true.  In the meantime, if you don't exceed the  Amps2 number for your power supply voltage that won't be an issue. (update: see below)

(Update) Some people have asked why "Charger" is in quotes in the title.

  • The technically correct terms are "power supply" for the thing that plugs into the wall and "charger" for the circuitry that supplies electricity to the cells.  This is also the common industry usage.  A typical RC charger includes the circuitry to properly charge "dumb" LiPo batteries.
  • DJI uses the arguably "technically incorrect but more commonly used" term "charger" for the power supply.
  • Displaying EastBay RC's famously pedantic nature, we therefore put "charger" in quotes.

(Update) DJI has some good information on their wiki.  Specifically, this datum:
7. Over Current Protection: Battery stops charging when high amperage (more than 10A) is detected.
If this situation is detected, the document indicates that LED2 will blink twice per second.

So the total power provided to the voltage converter should be under 260 watts.

blogodex = {"idx" : ["Inspire 1", "power supply", "DIY Inspire"]};

Tuesday, April 7, 2015

Things to try: the Dream Flight Libelle DLG

Rather sweet, and not crazy expensive like so many DLGs.

"There are few experiences in model aviation more satisfying to the soul than flying an efficient, slow-moving glider that has been launched to soaring altitude by hand. The Libelle takes RC hand-launch glider flying to the next level, building off of the global acceptance of the Dream-Flight Alula. Until now, this type of experience had been out of reach for many pilots for a variety of reasons. The Libelle is for everyone; it can be assembled, balanced, and trimmed for flight by pilots of any experience level."

Lots of info here:

blogodex = {"toc" : "Dream Flight Libelle DLG"};

Sunday, March 22, 2015

Getting Started with the DJI Inspire 1

WooHoo, EastBay-RC has bitten the apple and obtained a DJI Inspire 1.  Prepare yourself (we hope!) for some eye-poppingly gorgeous scenic imagery, and some EastBay-RC style tech notes on the Inspire.

First up, a quick series on getting started with the Inspire.  Everything from out-of-the-box to registration, setup, configuration, and testing.

This should be everything you need to get ready to launch.  And we're working on that series now!


1.  Unboxing
2.  Charging and Powering Up
3.  Connecting and Registration
4.  Attaching the Gimbal
5.  Updating Firmware
6.  Calibrating the Compass
7.  First Dry Run
8.  Second Dry Run
9.  Micro-SD Caution
10. Attaching the Props

Playlist Here!

(sad note: can't figure out how to get the playlist to work!  click the link above to see the entire series.)

Maiden flight:

blogodex = {"toc" : "DJI Inspire 1", "idx" : "EastBay-RC Guide"};

Thursday, March 19, 2015

Taranis D-Series Telemetry: Lightning Version

Here's what you need for Taranis D-Series telemetry setup.  This is the lightning version, focuses on battery voltage and skips what you don't need to know.

Hardware Setup

  • FBVS-01 is the voltage monitoring unit.
  • The documentation is confusing.  You don't need to modify the default power options.
  • FBVS-01 is supplied without connectors.  Attach your own connectors as necessary.
  • One end attaches to the D-Series Rx telemetry port.  The other end attaches to your battery.
  • Comes with a cable, attach it to the Rx.
  • Only need to worry about the two left connectors, ground and positive.
  • You can get rid of the other wires.
  • Final connection:   Battery -- FBVS-01 -- Rx
Telemetry Setup
  • Go the the Telemetry screen of your model setup menu.
  • Set A1 Range to 13.30V.  This monitors Rx voltage.  You probably don't care about this if you're flying electric.
  • Set A2 Range to 19.8V.  We'll cover why this is the right value later.
  • Set the low and critical alarm values.  For 3S, 10.5V and 10V are good.
Audio Voltage
  • In the Special Function menu, set SF1: SB Down, Play Val, A2, 30
  • When you flip switch B down, the current voltage will be announced every 30 seconds.
  • When the voltage drops below the low and critical levels, you will get repeating announcements appropriately.

That's all you need to get it working!

blogodex = {"toc" : "Taranis", "idx" : ["telemetry", "D4R-II"]};

Wednesday, March 11, 2015

Hubsan Q4 MicroQuad Review

Our friends over at GearBest sent us one of the new Hubsan H111 Q4 MicroQuads for review.   They've got it up for presale:

(Work in Progress)

It's a really small unit.  The controller seems like it would be too small, but it's actually quite comfortable to hold.  I don't think you could pinch them, though!
Here's the LEDs.  The front LEDs are blue, although they look mostly white on the green mat.  They make the unit pretty visible.
The box is pretty nifty.  It's interesting to see this level of design.
The quad comes mounted on these tabs.  Look at the tab on the front right.  See the long thin piece? Push it down and the unit will slide out of the tabs smoothly.  If you try to push the quad out without moving the long thin piece I think you will end up messing up one of the motor mounts.
The radio is inside the main box.  There's plenty of extra room for batteries, etc.
And the middle section has a storage compartment for the USB powered charging cable and spare props.
The transmitter takes two AAA batteries.  It snaps shut.  There's screw holes in case you want to secure the battery compartment.
The radio come in either mode 1 (right hand throttle) or mode 2 (left hand throttle).  Binding is done by turning the quad on followed by turning the radio on.
The charge cable attaches to the back.  There's a tiny on/off switch right next to it.
The cover pops off.  It comes in five different colors.
the 100 mAh battery has a double-sided sticky pad holding it onto the board.  It comes off with a gentle pull.  Unlike some other nanoquads, the battery is not soldered onto the motherboard but instead attaches with a Micro JST connector.
Here's the board.  Note that the power to the motors goes through the board, and the pads at the end of the arms are labelled positive and negative.

The battery connector is Micro JST style.  I'm hoping that GearBest will carry some, but if not I will make some using the technique here.


(coming soon!)


Concord Model Engineers Minutes, March 2015


Tuesday, March 10, 2015

CALL TO ORDER:  7:33 pm


Monthly meeting, Second Tuesday, 7:30 at Concord Airport Terminal.

Friday Fun Fly, Third Friday, 7:00 - 9:00 pm.
Gym at the Church of the Nazarene, 1650 Ashbury Dr., Concord

Fun Fly this month on March 20.


The treasurer is absent.  As far as we know he has not absconded with the balance.




New member Sam introduced himself to the members who have not met him.  Sam is a senior at Northgate High School and is working on a model plane for his senior project.

If you aren't getting mail from Chuck, send him mail.

A discussion regarding lastest FAA regulations.

Picnic will be on May 16.  Details to be worked out.

Gate code has been changed.






Stephens Aero, Woody.  5A brushed motor.

P30 Squre Eagle, 30'' wingspan, 28'' len, 90g.  Designed by Phillip Hartman, 1977, easy build, good starter.


Gallon of 10% nitro, box of props, BHM Pee Wee Pup, BHM Nova, Zap Glue Set, Miss Stik Park Flyer, Tube Ambroid glue, 2E Square Eagle kits, Charger.


blogodex = {"toc" : "CME Minutes"};

Two great videos about indoor flying

Donatas posts a practice video for an upcoming F3P competition.  Rule 1: Politely ignore the rules of physics!  We've mentioned this plane before, the 2S Victory designed by Alexey Lantsov.  It's available for sale now, about $600 or so including the custom-built coaxial motor. I have no idea how it's shipped!

The ever-awesome flitetest crew explores the world of F1D indoor free flight.  It's really interesting, and amazing that you can get over 30 minutes from a rubber-powered plane.

blogodex = {"idx" : ["F1D", "F3P", "Flite Test"]};

Sunday, March 1, 2015

Recording Taranis Audio Files

Here's some notes on recording Taranis Audio Files.  It assumes you can (a) download and install software on your computer and (b) see your Taranis SD card.

  • Project Rate (Hz): 32000
  • Audio Track: Mono
  • Sample Format: 16-bit PCM
  • Export Format: WAV (Microsoft) Signed 16-bit PCM
  • Audacity -- Open source, multi-platform recording software.
  • CleanMyDrive - (Mac) Cleans junk files when disk is ejected.  Use this to get rid of the extra files the Mac Finder puts on the SD card.  Some of the filenames are too long and confuse the Taranis.
SD Card Location
  • User sounds go in /SOUNDS/en
  • System sounds go in /SOUNDS/en/system
  • The SD card will show up in the Finder (Mac) or on the Explorer (Windows).
  • If you're on Linux i'm sure you already know how to find it. :)
  • "en" is for English.  I think there's corresponding folders for different languages.

blogodex = {"toc" : "Taranis", "idx" : "audio recording"};

Tuesday, February 24, 2015

WLToys V686G Mini FPV Quadcopter

Here's some notes on my review of the WLToys V686G Mini FPV Quadcopter. It was sent to me free of charge for review by GearBest.

The unit is available here:
I don't get any money for this, but there's has a coupon code GBV686G.

Executive Summary

  • It's a good flyer and I think it will be pretty popular.
  • Video is pretty decent for the price.
  • Lights are great...  this unit looks good at night.
  • Buy some extra batteries and a charger if you don't have one already.
  • The manual is pretty terrible.  But I'll summarize everything you need below!
  • Constant Tx beeping in heading-hold mode is crazy annoying!
  • Doesn't seem to state video channel.
In the Box
  • Quadcopter, Transmitter, 1S 780mAh Lipo Battery
  • HD Camera, Video Monitor, Video Antenna, 4GB Micro SD card, USB Card Reader
  • 4 spare props, 4 prop protectors, Screwdriver, Monitor mounting hardware, Manual.
  • LiPo and Monitor chargers, manual
Note that the web page advertises a 2GB Micro SD card, but mine came with a 4GB card.

Battery Spec

  • 1S,  780 mAh, JST connector, no specification on C-rating but I'm guessing it's 25C
  • Transmitter takes 6 AA batteries (not included).
Setting Up

Setup is easy.
  • Charge the LiPo battery and Video Receiver.  Put AA's into the Transmitter.
  • Attach the Video Receiver to the Transmitter with the supplied hardware.
  • Put the quadcopter on a flat surface and plug in the battery.  The light will start to flash.
  • Turn on the Transmitter.  After a few seconds, the quadcopter light will go solid and the Tx will stop beeping.
  • Put the battery into the bottom of the compartment. The wires will fit nicely into the top.
  • Ready to Fly!

The stick controls are standard.  Special controls are:
  • Left shoulder button : video record on/off.  The blue camera light blinks while recording.
  • Right shoulder button: Flip mode. Click, hear fast beep, move right stick in direction of flip.
  • Button 1,2,3,4:  Rates: 40%, 60%, 80%, 100%
  • Button 5:  Lights on/off
  • Button 6:  Camera, still picture
  • Button 6 (2 second press) enter/exit headless mode

Monday, February 16, 2015

Notes onOneShot 125 ESC Communications

Executive summary:
  • uses a pulse with of 125-250 usec, rather than the typical 1000-2000 usec.
  • sends a pulse ("oneshot") once per execution of the flight controller main loop.

At the time of writing, Flyduino KISS ESCs and Naze boards support the protocol

Cleanflight notes. Originally put into BLHeli(?). Nice video explanation.

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Friday, February 13, 2015

Fixing UMX Radian Porpoising

BrownShoe at RCGroups posted a note about eliminating porpoising on his UMX Radian.

After I established the CG at 32 mm, I cranked in some negative elevator with my needle-nosed pliers; the little U-bend was almost closed. She flew kind of crazy. It was way too much negative elevator and the wind was very choppy and I came close to crashing. What I noticed was, it did not porpoise! Ha! I landed and opened up the U-bend some and tried again. She flew with nary a dip! It was the nicest flight she has ever flown!  
I performed a dive test as best I could while trying to remember what to look for. It had a nice gentle rise and not an abrupt porpoise. Nice! I flew three packs and she handled very well in spite of the very choppy air. I let it glide hands free for a good ten seconds. Finally it flies like it is supposed to and I'm having maximum joy now. 

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Tuesday, February 10, 2015

Concord Model Engineers Minutes, February 2015


Tuesday, Feb 10, 2015

CALL TO ORDER:  7:30 pm


Monthly meeting, Second Tuesday, 7:30 at Concord Airport Terminal.

Friday Fun Fly, Third Friday, 7:00 - 9:00 pm.
Gym at the Church of the Nazarene, 1650 Ashby Dr., Concord

Fun Fly this month on Feb 30.


Previous Balance $2582.68
- web site fees     99.00
Current Balance  $2483.68


The club welcomes Sam, a senior at Northgate High School.  Sam will be working
on a model plane for his senior project.

Indoor flying venue.  We will continue at the prior venue.  If anyone knows
of other venues please let everyone know.  George knows a guy who knows
something about the Moffit Field hangar.

If you need a badge, let Ron know.  Needs your name and AMA number.

Christmas party, concensus reached, same time (second Tues in Decemeber),
same place (Buttercups)!


Feb 28, Wagel free flight, weather permitting.


Mike Woodring, two Flite Test Bloody Wonders.

Mike Woodring, Flite Test F22.

Mark Harrison, EZFly. More pics here. Video below.

Mark Harrison, F22.  Notes here. Video below.

Jerry, Sigg Twister.  Finished with orange rustoleum, matching the monokote.

Lee, Ubanko Contest wing, from Ukraine.  Had to order off of Facebook.


bundle of balsa, roll of monocoat, BHM Vulture combat kit, .049 Cox engine, Zap Glue, Interceptor Free Flight kit, 3D Kit Lazer Cut, Roll 0.15x52 flying wires, Solder jig, Screwdriver set, digitial multimeter.



F22 flying around.

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