It's Over, It's Done!

Now that the genius project is finished I can safely say that.....
I flipping did it! 



That right world, I mastered the fine art of flying really small aircraft really fast. I learned a lot about how to manage weight and wind on these small aircraft which I hope to be able to use on my big quads. Already I found myself being able to take corners much better in my real racing quadcopter. I have found that my propellers bite the wind with such force when I use the coordinated yaw turning skills I developed over the course of my product.

 To be able to record the videos I needed for my presentation, I modified my ev800 goggles with a DVR so I could record my flights and upload them to YouTube. This took a lot of research and planning to be able to do since their is no documentation for the modification. I ended up having to use an oscilloscope to find the video output of the integrated receiver. After I did this, I soldered the input from the DVR to the V-Out on the googles, and after using a multi-meter to find ground and VCC, those were soldered in too.
Look at how clear this video downlink is!

Tiny Whoop Vlog

Interview with Mu Chen from Eachine (5 + Int)

I had the opportunity to interview Mu Chen from Eachine. Eachine is a company that is powering the Tiny Whoop craze, providing incredibly fast brushed motors and electronics to consumers. Most notably, they created a pair of ready to use FPV goggles that are 1/10th of the price of the previously used fatshark goggles that used to be popular. This huge price drop is what made the hobby accessible to so many people. They also are the company that has graciously sponsored my project and provided me with free parts that allowed me to whoop.

Mu currently works in the motor engineering division of Eachine, creating incredibly powerful and lightweight brushed motors. He also has had a hand in the development of products like the QX90 airframe and the EV800 goggles that I have been flying with during my project.

I spoke to Mr. Chen via a Skype voice call, which was no easy feat. He is currently in Hong Kong which is a full 12 hours ahead of us. I had to wake up at 5:30 in the morning to be able to call him at 5:45am our time, the only time he was available. We has a good conversation regarding the future of Tiny Whoop as a competitive, the technical innovations he has worked on, and how I can prepare for the HUGE changes that are coming to the hobby.

According to Mu, tiny whooping events have popped up all over both the US and Asia, with people being able to fly with large groups of like-minded pilots and compete for prizes. He predicts that racing events will continue to spread and bring new people into the hobby. He also said that Eachine will be sponsoring racing events and providing prizes to be sure that tiny whooping, especially on their popular E010 and QX90 platforms.

As for the future of racing technology, Mu Chen says more powerful batteries, like the LiFe batteries I talked about before, are going to become available. These newer batteries will have higher C (Discharge relative to capacity) ratings making punchouts and quick, agile movements more effective. Most importantly, it will INCREASE the maximum angle of bank for quads because they will be able to come out of turns easier than without the extra power. This is going to be huge and prevent plenty of crashes.

To prepare for the future of flying, Mu Chen recommends practicing in a simulator where you can adjust the properties of the battery virtually. He also recommends investing in 2s 7.4v brushed equipment, as that is the direction he sees the hobby moving, away from the standard 1s 3.7 volt packs. Luckily most of the equipment I have can be converted simply by soldering pads together on the trace section of the PDB.

My conversation with Mu Chen taught me a lot about Tiny Whooping and gave me another reason to keep with the hobby, especially due to the radical changes it is soon to undergo.


.

Improving and Reinforcing (4)

I reached a HUGE milestone this week. I reached a point in my piloting where I could increase the maximum angle of bank, AKA exponential rate, so far that a standard camera angle could not properly allow me to see in front of the craft. I increased the maximum angle of bank to allow the craft to go much faster. This means I primarily see the floor. I gave my camera a 23 degree tilt so that when I am at full bank, the camera is only angled down 7 degrees instead of the 30 it was before the up tilt.

Here is a picture of my super ghetto tilt mount made with my 3d printer and rubber bands.

I also used some UV activated adhesive compound as to secure to power connectors. I had to do this after the battery ejected in a crash, pulling the negative terminal of the JST-XH connector with it. Luckily, the wire ripped above the joint and it didn't pull a PCB pad with it.  After re-soldering it, I applied and activated the glue because next time I may not be so lucky as to not lift a pad. If that happens, I would have to rebuild the entire quadcopter. This little protective step should go a long way.












Finally, I upgraded lens assembly once more to a lens with better optics. This new lens has significantly less distortion in the center of the field of view. This works great with my new higher bank angle and faster flying as important objects now are solely in the center of my headset instead of to the sides like previously.

A week of improvements (3)

Over the past week, I have continued to fly my tiny whoop religiously. I also have been focusing on upgrading and improving my setup in order to get better performance from both my quad-copter and FPV gear.

The first improvements I made where in software. One of the reasons I chose to use the F3 EVO flight controller on my drone instead of a cheaper, simpler one was because of its programmable and customization nature. As such, I plugged it into the computer and made a few tweaks.

The first thing I did was add EXPO or exponential control to my throttle, roll, and pitch response. EXPO changes the aircraft response curve from a straight line (linear) to an S-curve, flatter in the middle (less sensitive) and steeper at the extremes. This means you get more precise control in the range around neutral where most flying takes place, while allowing for full throw (!) when the sticks are at their extremes. You can see the result bellow.

The second thing I did was increase the rates to the vehicle response. In a non-technical sense, rates controls the rate of rotation on each axis. Say I have the pitch and roll rate at .30, the copter will do flips and rolls at about 360* of rotation per second (or one full flip / roll per second) when the stick is held hard over. If you raise the rates to say .60 the copter will now to 2 full flips / rolls (720*) per second with the stick hard over. I used the CLI command line to change the rates on the quad and make it much more responsive (read: faster) in pitch, roll, and yaw.

I also made a pretty significant hardware change as well. I (along with almost all quad pilots) use Lithium Polymer (LiPo) batteries to power my machine. LiPo batteries have a huge advantage over traditional lead-acid or nickel–metal hydride batteries due to their high max voltage of 3.7v per cell for nominal discharge while still maintaining a low weight. Recently however, Lithium iron (LiFe) batteries have come to be available to pilots. They provide a powerful 3.9v per cell nominal voltage at the same weight. This means more power for maneuvers and punch-outs!

Take a look at the voltage of a LiPO battery (yellow and blue) vs that of a LiFe battery (purple) when discharged at 30 amps.

It is clear that the LiFe battery is able to provide a higher discharge rate and voltage for a much longer time than the standard LiPo battery with the same C-raiting.

I have taken the plunge and bought 5 additional batteries, all LiFe and will be receiving them soon for even more power.

Finaly, I changed the lens on my FPV camera from a wide view raceband lens to a narrow focus unify pro lens. You can see the difference bellow and it is quite an improvement. (this picture is not mine but it shows what the 2 lenses look like on a similar camera to the one I use)

Fun and DESTRUCTION (2)

Wow does time (and my tiny whoop) fly. I have had a great week of flying my QX90 inside and outside. I have brought it with me whenever I go out, as you can see from some of my videos post which take place at my Uncles house. Crashing has been a pretty common occurrence for me. I have broken more than 20 of my 3D printed prop guards. Luckily, they cost less than a penny each to print. I also have broken 6 propellers (costing a whole $0.15 each). I hoped this would be the extent of the damage but unfortunately that is not the case. On Monday, I flew with a battery that was too low for flying and was unable to complete a punch-out as planned. Because of the resulting voltage drop stemming from sudden amp draw on the already depleted battery, the craft could not complete the banked turn I tried to do and started to oscillate about 35 degrees from its axis until it flipped and hit the ground. This picture shows why rapidly moving above 35 degrees on such a small aircraft is so problematic. Instead of being felt by passengers like the picture says, it was applied to the opposite end of the aircraft as well as the FC, which is MUCH more problematic.

The impact knocked the lens and CMOS assembly off of my FPV camera. Unfortunately, this is not something that can be easily fixed. I ended up having to buy a new camera  and replace the existing one I soldered the replacement unit into the lowpass-filtered section of my F3 Evo flight control board and it works! I was only out of the air for 3 days, but if felts like forever.

Here is a video of the crash. When the video goes white, that is when the camera fell apart, yet the TX still transmitted video (impressive!) 

The damage 

Whoopin Around the Chicken Coop

Over Under, & Through -Tiny Whooping

3 Minute Long Tiny Whoop Flight without Crashing! -Personal Record

Welcome to Team GreenHopper FPV (1)

This was my first week to Tiny Whooping! What fun. Tiny whoop is the newest craze in the multirotor hobby which involves small, brushed quadcopters carrying AIO camera with a live, analog down-link. Tiny Whoops are all custom built aircraft that use extremely powerful coreless motors made by Chaoli  and advanced flight controllers like the F3 Evo running sophisticated software like BetaFlight.  My goal is to be able to reduce my lap times by 33% on multiple courses. I plan on flying indoors in both large and small rooms, outdoors in an open area and outdoors with obstacles. I also am making a YouTube channel, Team GreenHopper to show my progress.

The aircraft I will be flying to start out is a custom built quadcopter based off the carbon fiber QX90 frame. It has the newest F3 flight controller and a super small flysky receiver to take control input from. It took over a week to find the best parts to use and over an hour and a half to build it. I certainly got to practice making a lot of very small solder joints which was difficult.

 Here are a few pictures.

I also modified my ev800 goggles with a DVR so I could record my flights and upload them to YouTube. This took a lot of research and planning to be able to do since their is no documentation for the modification. I ended up having to use an oscilloscope to find the video output of the integrated receiver. After I did this, I soldered the input from the DVR to the V-Out on the googles, and after using a multi-meter to find ground and VCC, those were soldered in too. In the end, it worked out well as you can see in the picture below.


Finally, I added a few 3D printed parts to the quadcopter that I printed out at home with ABS filament. I added an antenna protector to keep the AIO camera safe and prop guards to ensure my propellers don't mess up the walls. Overall, it was a very productive week!