upgrade gaui 500x to DJI NAZA stabilization project


UPDATES: See notes at the bottom

Because the DJI NAZA multirotor stabilization unit ships in a box with no instructions. And when you eventually do find the NAZA PDF instructions on how to configure the NAZA for your quadcopter you find that only page 7 discusses the actual installation of the hardware. So here is some guidance.

My 500X was purchased ARTF with a JR radio and the 334 stabilizer (with the 334 stabilization disabled and a warning not to use it!?) In other words, a 500X out of the box is a manual-fly-only type of thing. You can do it, but for video I wanted better stabilization.

The “open box” photo of what you get with the NAZA followed by before and after shots of the installation. Note that it isn’t complete yet as it comes with pre-tinned connections for power but no connectors and I need to order those or splice into an existing line. See more notes after the gallery.

On the JR receiver, to fit the wires that shipped with the RAZA I had to cut off and dremel-smooth the “L” extensions on the bottom of the connectors to make them fit in the RJ receiver. And I only had to modify the one end (obviously) Just be careful the orientation is correct. I should probably buy another receiver for the Spektrum but that isn’t in the budget right now.

UPDATE: A few lessons learned:

First – the DJI NAZA ships with no (zero) documentation. Electronics in a box. From there it is you and google. If you are converting a GAUI Quad there are a few CRITICAL items to note and then so not so critical.

  1. DJI NAZA does NOT number the motors the same as GAUI. Although the rotation of the blades (pusher, tractor or 10A and 10B if you are using GAUI parts) is the same, the controls are different. Specifically 1 (right front) is one on both. But NAZA goes counter clockwise. This is the exact opposite of GAUIs cofig. See the graph from the F450 manual below. If you don’t switch 2 and 4 you are screwed. Or at least it will cost you a few props.
  2. The NAZA software is an adventure. See this guy’s NAZA Software for Gaui configuration screenshots. Not exactly how I have my quad configured, but close. (I’m very traditional with my stick movements. Down is throttle stop. Up is throttle up. Right controller is aileron and elevator. Left is rudder. Etc….
  3. Much of the NAZA documentation comes from hovering over a section in the software and reading the dialog box on the lower right. Read it!
  4. You will forget the safety feature of “both sticks down right” to initiate and think your controller didn’t bind. It did. You just have to do the “two sticks lower left” or “two sticks lower right” with the NAZA to get it going for safety reasons. I moved from my JR to the Spektrum 8 and had no problem binding. But did have to customize the “landing” gear controller to reach the Attitude and Manual positions. You can NOT do this on a Spektrum 5, so don’t try.
  5. Known issues- the motors on the GAUI are incredibly sensitive to hits or friction in their casings. I replaced an ESC that I didn’t have to because it was just a small crack in the engine mount that only became an issue under lift conditions. i could not replicate it with the spinners off. This caused me to burn ou t a second motor beforenarrowing in on the issue. Thus I don’t recommend the hard-to-access GAUI frames.


Example videos:
The 2012 Art Car Ball at the Orange Show

St. John Vianney Catholic Church

2012 Houston International Festival

Rebuilt GAUI with DJI Naza

“how do you know how to build rc helicopters?” she asked

I was talking to a talented artist at the company recently and found myself talking about a few aerial photos I had taken over the weekend using the Quadracopter and the new camera mounting and FPV rigs.

It was an obvious question, but it caught me off guard. She asked “How do you know how to build RC helicopters?” I was dumbfounded.

My answer at the time was shallow – all I could think to say was “I don’t know.”

I followed up with, after a beat or two, “I have been building things since I could move my hands. Mud pies. Cars from spare electrical parts left over from the maintenance men. Fires from sticks in the deserts of Mexico. Contraptions. It didn’t matter what. At our house when something broke, a safe with a lost combination (my first venture into social engineering although we didn’t call it that at the time), a hidden compartment, a washer in need of a new belt, a broken a can-opener, it was a given that the broken unit would be given to me for repair. Though the youngest for many years, now the 3rd of 6 kids, I was the one who either fixed it or took it apart in a determined effort to build robots. Or cars. Or dragons. Or spaceships. Or sometimes the diagnosis was above my paygrade and we needed a professional to fix it (hint: plumbing). I didn’t mind this as I could watch them.

There is a carpenter somewhere in Connecticut who hates me because I watched and wanted to help him redo our front porch. He tolerated me, and I learned a LOT about carpentry.

And realize giving a kid like me electronics to fix is a serious conflict of interest. If I FIX the can-opener then it must be returned to the kitchen for family use. If, however, it was un-fixable, then the motor, the circuits, the power supply that converted the AC current to DC was mine for whatever I chose to do with it. It was parted out into shoe boxes I kept under my bed and had dreams wondering why the motors didn’t work when plugged into the wall directly (hint: alternating current. who knew?)

I remember in 4th and 5th grades in particular I really hadn’t mastered the art of NOT touching the wires and shocked myself many times. 110 V AC when you weigh less than 100 pounds is quite a jolt. But I’d keep quiet for fear I’d lose my role as repair/rehab/mad-scientist in the family. It never occurred to me to unscrew a particular fuse (young kids – fuses were round things you screwed into what we now call a “breaker box” and if they blew you had to replace them. NO LEVERS.)

My Dad was in residency at Bridgeport Hospital at the time and regularly brought home used medical tools. Scissors for cutting bone, cauderizers (basically small portable soldering guns), scalpels, you name it. And these would be carefully cleaned and then assembled into whatever the project of the day was. I was the go-to guy in the neighborhood to build your slingshot for years because I had access to surgical tubing (“used” of course like everything else he brought home but what did I care?). And I was good with a pocket knife and tools. I made wrist rockets before wrist rockets.

Tools. Then it hit me. The answer to Erica’s question. “How do you know how to build RC helicopters?“ The tipping point for when I REALLY started to make things was when we moved into an old house in Bridgeport Connecticut. When we moved into the house it had all of the windows boarded up. From the inside. The old widower was a nervous sort and her husband, having died many years earlier, her response was to go into lock down. She either passed away or was being moved to an assisted living complex and her children put the house up for sale. My parents bought it. And with that house gave me the most amazing gift. Tools.

The basements in the Northeast, at least in Bridgeport where my family was originally from, have oil furnaces that heat the house. Oil is dirty, particularly fuel oil, and basements were covered in a constant level of black soot and plenty of humidity (the better to rust with). This basement in particular hadn’t been cleaned in years and I guess the sellers just didn’t want to deal with it. I didn’t mind.

For an explorer such as myself this cellar was HEAVEN! I found closets of jars for canning supplies apparently used by the lady of the house many years earlier. And I found drawers and drawers of ancient soot covered hand tools. Hand drills. Hammers. Awls. Files. Nails of every sort and size. Pliers. EVERYTHING. Tools I never knew to ask for because I didn’t know what an awl was. How can you ask for something you don’t know exists never mind understand how it was used?

I. Had. Tools. A quick trip to the library and I found a book on wood working and figured out what all of this stuff was. Old wood screw clamps for example aren’t obvious in what they are used for. Libraries answer those questions.

I cleaned the tools as best I could. And the hardware store was a 10 minute bike ride away on the way to Bradley’s or Caldors’. Shoveling snow and odd jobs were enough to buy a few nuts and bolts and 3-in-1 oil (this was before WD 40 folks). I found wood boards and 2x4s floating in the rooster river. Picked up junk along the streets. It didn’t matter. If it was a material I could cut and shape then it was mine. (side note – smell plywood before bringing it home. Of all of the woods in the “wood” family plywood is apparently peed on the most by dogs or people and there is usually a reason it gets thrown out. I learned that. You’re welcome.)

I built a go-cart. It was agile but slow. I didn’t understand bushings or bearings. The steering mechanism was a broom stick with rope wrapped around it. The “wheel” portion for the driver was a barrel that when you turned it shortened one side, lengthened the other of the clothes line to turn the front axle. And that was how it was steered. Believe it or not it worked. Sort of. To be fair there isn’t much steering going on when going down a hill on a neighborhood street.

I dreamed of entering the Pinewood Derby until I read the rules and realized I couldn’t afford the parts (Fiberglass! Really!? I hadn’t evolved that far yet.)

The tools, when cleaned up, most of which I still have, look like this one from
RICHARD PICK & HELLER CO. And yes, this is one from that basement that is on my workbench right now. And has been my “go to” pick for the last 30+ years.

pick

And the tools WORKED. And tolerant parents let me do my thing knowing that if a lock in the house needed to be picked (ironically you don’t use a pick to pick a lock. Long story) or an appliance fixed I was the go to guy despite being the youngest of the older three.

I tell this story for three reasons. This evolution had three critical ingredients:

First – my parents gave me the freedom to wander around a basement covered in soot and I found TOOLS. And I used them to help the family but also to build, create, explore, create.

Second – A bit of luck. I got a bit lucky that they left two closets full of hand tools, jars, nails and rust covered awesomeness in a black basement with rock walls. A kid in a family of six children with little income had zero chance of acquiring an entire set of hand tools. I got lucky. I inherited them as far as I was concerned.

And third, I became the master over materials that for most children were objects. Wood and steel was suddently maleable to me. It was material I could turn into whatever I wanted. And that let my imagination go everywhere. This kid had hit the industrial age.

Almost every single thing I tried to build failed. Didn’t work. Crashed. I didn’t care.

I never got the physics quite right in the beginning. I can’t tell you how many rockets I have sent into space or at least a neighboring neighborhood miles away when my intention was a safe launch and recovery. Wind up silkspan and balsa airplanes powered by wind up rubber bands lost to thermals that lifted them into oblivion (high wing models fly great – and you lose them. Low wings NEVER fly right unless you weigh them down because they lose aerodynamic lift with a loss of speed. Thus a rubber powered low wing airplane always lands badly. Which is why real airplanes keep their engines on when they land.) Just a tip for the real pilots out there.

I never put my name or phone number on those home-made paper-towel or toilet paper roll based rockets with hand-carved balsa cones and writing-pad-back-cardboard cutout fins because I figured it was better to lose a rocket than get in trouble for landing a rocket in someone’s window. Or to explain how that airplane landed on someone’s car. It was a different time and the idea of causing problems for the family was something that I would never do. Sadly I think there is more tolerance for this in modern times when everyone gets a trophy for everything. If I broke something I had to fix it and then got grounded. Prudence you know. Let the plane/rocket go and use a different engine next time. Or adjust the wind-angle for launch. Being determined I kept over powering the rockets and trying to predict the wind and the chute delay for recovery.

So to Erica who asked “how do you know how to build RC Helicopters?” all I can say is that it was a bit of luck, I started building, and now I can’t remember a time when I didn’t.

Of course building is much easier these days with rubber handle pliers (fewer of those shocks!), Dremels (oooooh), hardened steel screwdrivers, metric hex tools, affordable ball bearing sets, etc. But it got started in a filthy basement that I explored, cleaned and found the most wonderful gift of all – an old man’s tools. I thank him. I hope he knows that his tools changed my life. They enabled me to CREATE!

Thank you Sir, whoever you are.

I still have most of his tools. I still use them daily. Extensively last weekend. They sure knew how to make great tools back then. And that pick pictured above is PERFECT for working on quadracopters. Go figure.

quad

And that lets me take videos like this:

Soot covered tools. Rule. That’s the best answer I have for you Erica. And thank you for the great challenging question that led me on a wonderful trip down memory lane. I appreciate that.

quadracopter – starting to feel like mad max

The quad. Rebuilt it tonight. Took a chance that one motor was still working after the last crash. It wasn’t. You can’t test that. They all spin up. You do a slow test launch and you get an immediate flip.

Lesson learned – if a motor is damaged or touched, just replace the damn thing. Now I have to replace the motor which requires a lot of labor, and I have a motor.

Starting to feel like the gyrocopter dude in Mad Max putting everything together with duct tape and wire. Sheesh.

quadracopter update – not that anyone asked

Quadracopter update — not that anyone asked — Prototyping new landing gear with clear legs for LED lights for night flight (red in front, blue in back) and 16 centimeters of clearance for a GoPro mount below the body. 4 centimeters to spare for hard landings and leg flex. Interchangeable with lighter gear for stunt flying when the camera isn’t attached.

In this photo the old landing gear is still attached and it is just sitting on the new gear. I haven’t built the new dampening mechanism yet. Was told by an engineer friend that my springs on the current video/camera front mount “were dampening for the wrong frequency” so while I will keep those for hard landings, I am shifting mass to the landing gear to lower the COG and and putting ALL of that on the other side of several sheets of rubber/foam between new aluminum plates to smooth out the video against the electric motor generated high frequency vibrations.

The main-plate vibration dampening sandwich is tentatively set to look like this:

============================== <-- 1/16 aluminum sheet
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ <-- rubber sheet
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ <-- rubber or foam sheet
------------------------------ <-- 1/32 aluminum sheet
possibly counter-opposing cut-outs in the aluminum sheets to save more weight.
      /\        /\    
     /  \      /  \   
     \  /      \  /
      \/        \/
=========================
  /\        /\       /\
 /  \      /  \     /  \
 \  /      \  /     \  /
  \/        \/       \/

Not necessarily that pattern. It was the best I could do with a <pre> tag and years since I did ASCII art (kids – ask your grandparents what that was.) But you get the idea.

Anyway, the first adhesive test failed having problems with sticking to the aluminum. Although a sage friend this morning suggested cleaning everything with rubbing alcohol before joining might fix it. If not it will be size 4 or 6 bolts with rubber washers holding it all together so there will still be no metal-to-metal contact for the vibrations to pass through. I just need to be sure the adhesive won’t come off if I do a roll with the camera attached. That would be bad.

Or to put it another way, the quad is not flying this week, but will be back with new capabilities by the end of the weekend. And then you won’t see the rotors in the video like this one

So if you see a camera and landing gear falling out of the sky with no vehicle attached, please return it? Thanks!

t-rex 450 project continues (tail boom complete)

T-Rex 450 project continues

Tail rotor hub (preassembled) successfully mounted to the tail boom. Tail blades installed. Haven’t tightened everything yet as the tail boom braces and the tail pitch ball link will need to be adjusted once connected to boom mount in the main frame. (Note to self: order the helimax ball link pliers….)