Discussions

Hello everyone,

I use to fly radio control airplanes in the mid 1970s to early 1980s but left the hobby during my college years to chase girls and move into life. I started with the RCM Trainer 40 with a K&B 40 and Kraft 5 channel radio. When my high school age daughter decided to build and learn to fly a radio controlled plane for her senior project I decided it was a great time to get back in the game. WOW what a change in radios, power system etc. Since I own a video production company I was immediacy drawn to the camera carrying multirotors.

Before I go further I want to address the total NewBs. After getting back into the R/C hobby and learning to fly mulirotors I highly recommend you start by mastering the basics of flying with a simple 4 channel airplane. Learn orientation, and get your control reflexes built up so moving to a multirotor will be easy. It is much easier to find an experienced R/C airplane pilot to teach you them a multirotor expert to guide you. Once you get into multirotors, as popular as they have become, you will most likely BE the expert in your area when you bring out your first quad etc.

I started this whole project with the goal of having a DSLR camera ship in the end. I'm not there yet as I still have to build and test a camera gimbal system.

I started by building a basic quad set up using a HobbyKing SX450 frame with a KK2 board using the same motors I intended to eventually use on the Hexa. This quad served as my learning test bed system. It was way over powered but worked fine. The KK2 was flashed with a 1.5 firmwear upgrade and worked great within its limits and allowed me to learn to fly the quad.  Real success came when I moved to the ArduCopter APM 2.5. I chose the APM 2.5 system over the NAZA M system due to cost and features. The APM 2.5 now is mature enough to run out of the box for NewBs and getting better all the time. However I have to warn any NewB that the APM 2.5 does require more time and tweeking with a higher learning curve then the NASA M. The upgrade path for the DJI NAZA is way over priced so I chose the APM 2.5.

During the quad build learning phase I decided to get the Turnigy HAL Hexa as my next frame as it was affordable and had spare parts available. Here are some shots of the completed Turnigy HAL Hexa  build. My apologies IO thought I'd saved the construction pictures but can't find them on my hard drive. ugh!

IMPORTANT NOTE: When building the Turnigy HAL Hex / Quad build and attach the landing gear to the bottom plate FIRST! Do not attach the arms until this is completed. The landing gear parts were too tight to just slide together SO... I put the cross rods in the freezer for several hours while I put the support clamps out in the sun for the same time. When I brought the parts together a few pieces at at time I had maybe 5 minutes to get them inserted and aligned before the temperature difference evened out too much to allow them to move further. This Cold/Hot system worked great.

I extended the motor cables through the booms using 14 guage extension cables with bullet connectors at each end to allow me to swap out a motor or ESC in the field. Soldering the wires and sealing with heat shrink would save weight and be more secure.

I had to drill out the motor mount center holes to 7/16 inch to accommodate the Turnigy D3536 1250 kv C-clip. I used a small torpedo level to level all the motor mounts and marked the top of the booms at the motor mount to show any misalignment at a glance if I should (more like when) have any mishaps that bump the arms and mounts. If I were to go back and choose motors again I choose a lower KV version in this size range. like a 900kv or lower to swing a bigger prop with less power used. I did not realize the significant efficiencey improvement a lower kv combined with bigger low pitch prop can yield until I was invested in my motor ESC selections from earlier.

The Turnigy 45A SBEC escs were flashed with the SimonK firmware. I can positively say this made a huge difference in increased performance. I learned all this when building the quad test bed. If I were starting over I'd get the 55A version as the additional headroom in amps would be nice when I move to the larger 12" props given the higher  motor kv I am working with.

For the component stack I used nylon off sets with regular CD-rs for plates. They were easy to drill and had plenty of room to place the radio control receiver, APM, GPS telemetry modules. I put the APM at the top along with the GPS to get them away from the esc and power distribution cabling at the bottom of the HEX to reduce potential magnetic / electrical interference. Further testing will reveal if this accomplished that goal. As shown in the pictures I can just barely get the Hexa dome to mount and have left it off for this testing phase.

Next up after tuning this HAL Hexa is mounting a GoPro with a gimbal for the first camera system and a FPV system to allow me to see what the camera is getting. Then I can move to to using a DSLR if it proves to be better then my new GoPro Hero 3 Black.

I've already had enough fun with my first quad and this hexa to know I want a small quad with a GoPro FPV to buzz around low and fast for just the fun of it. That will be my next build.

http://youtu.be/cZVtpWPzfus

UPDATE: Well, after the initial two test flights in my front yard I went out to the local flying field here in Palm Bay Florida. Called "The Compound" which is a huge wide open area with subdivided paved roads etc. I wanted to do some circuit flying and test the altitude hold, loiter and tune the hex up.

I get out there in the late afternoon and the wind is pretty steady at 10 mph so everything looks good. I did several more flights with no problems. I even got a brief no wind period so I did an Auto Tune flight which worked great. Centered my transmitter trims and kept flying. On the next flight I was flying in Acro mode with the pitch set to 0 and roll at 150 which works great for just maintaining a forward flight with no pitch input. Then just after returning to stabilize mode "BAM!" an engine mount snapped on the right rear motor. I thought for sure it would drop like a rock (as a quad would) instead the AMP fought a tough fight and it stayed +/- within 30 degrees of level and came down semi controlled. I was able to get it back to me from about 50' up and 150 ' away to land near me just bending a landing skid a minor amount and NO PROPS BROKEN! Not even the prop on the motor with the broken mount dangling at the scene. 

There had not been any bumps or know mishaps with the mount so I'm left wondering if it was poorly manufactured or weakened significantly when I had to drill out the center hole an additional 3/32 of an inch. I reviewed the flight log and didn't see any noticeable vibrations. In fact the the graphs were excellent with only +/- 2-3 on the x,y,z accelerometers at hover just before the incident. The moon gel was working great.