Building a Quad – Assembly

After picking the parts the first thing I did was take the flight controller and plug it into USB and connect it to Betaflight to check two things. First just to make sure that it powered up before I started doing any soldering on it. So in case I got a defective part I would be sure that it wasn’t something I did on the workbench that broke it, and I’d more easily be able to get a replacement. The second thing was to see if it was to record the firmware target that the flight controller was using and make sure it was the most recent firmware version.

Then next thing to do to prepare for the build was to flash the receiver with the most recent firmware version from FrSky. This was a new process to me and involved downloading the firmware from the vendor, storing it on an SD card that I inserted into my radio, and then plugging the receiver into the radio using a wiring harness that the receiver came, then flashing the firmware.

Finally it was time to start building the quad, starting with the frame. I’d already watched a video of a more experience builder putting one together, but seeing it done once and doing it yourself tend to be very different experiences. For fun and to try to stay organized, I started out by organizing all of the pieces.

There’s four arms, blue standoffs, a top plate, a pair of bottom plates that sandwich the arms, and miscellaneous screws. Putting it together wasn’t too much different from assembling a Lego kit or any of the various children’s toys that I’ve had to put together after a birthday party or on Christmas morning. I think it took me about 20 minutes to get the bottom plate and arms assembled and be ready to starting on installing the motors and the electronics.

Before I started installing any of the electronics, I needed to tin all of the pads, and I figured that would be easier to do before I put them on the frame. In all of the build videos I’d watched to get ready for this, the builder would just put the board on the frame and then add the solder from there, but I was coming into this with just a little bit of soldering experience and I wanted to give myself the best chance at success. So I laid out all of the boards in the flight stack and made sure I knew which wires ran to which pad.

Then I tinned all of the boards at once: flight controller, four-in-one ESC, and VTX. The Caddx HD capture board on the camera had plugs and didn’t need any soldering.

Putting the ESC onto the frame as the base of the flight stack and installing the motors marked the first real part of the build for me as the quadcopter started to take shape. The process itself was pretty simple: screw a motor onto an arm, run the motor wires to the ESC, measure and cut the wires, solder them to the ESC. But cutting wires like that was a bit nerve wracking for me, as I was paranoid about cutting the wires too short and too long. On the one side I’d end up without enough slack and have to solder additional wire back on along with heat shrinking the joint, and on the other side I was trying to have a clean build plus extra wire would also contribute to extra weight. Which a few grams doesn’t sound like a lot but for a small 3″ build like this every gram counts.

After that the next step was the battery lead. As often seems to happen to me with this hobby, the part I was thinking was going to be easy turned out to be pretty difficult. It took a lot of work for me to get these two leads soldered onto the main battery pads of the ESC board. The heavy gauge wire and the big soldering pads on the board required a lot more heat than I’d been using up until now in order to get the joints flowed together properly.

Soldering the rest of the electronics was pretty easy. The hard part had been getting the documentation online for the various parts and making sure I knew which pads to use on the flight controller for the camera and the VTX. It had a pin header that plugged straight into the ESC board which made assembling the rest of the flight stack pretty easy.

Then came the big moment, plugging in the battery for the first time to see if it all worked. After going over all of the solder joints with a multimeter to see if I had shorted anything, I took the battery and plugged into a smoke stopper before plugging that into the battery lead on my new quadcopter. A smoke stopper is basically a fuse that will trip in the case when there’s a short somewhere so that you don’t release the magic smoke from the electronics. I’d bought one with a light and a reusable fuse at the same time that I ordered my parts.

The smoke stopper lit up green and the leds on the flight controller, receiver, and VTX are lit up as well. The best part though was hearing the startup tones playing as the flight controller and motors synced up.

After the battery test I connected it to my computer and went into Betaflight to check that all of the motors were spinning the right direction, and then change the settings on the two that weren’t. Then I plugged in a battery again and I checked that my radio would connect, and that I was getting a video signal in my goggles from the VTX.

At this point I figured I was just about done, I just needed to put the top plate on and the props. Which naturally is when I ran into the one problem that gave me the most trouble in the whole build.

When I picked out all of the parts, I remember adding up all of the heights to make sure that it would fit inside the frame. But I was looking at the height of the standoffs on the frame and not the length of the screws for the flight stack which were a couple of millimeters shorter. That makes sense to me now since you don’t want those touching the top plate and transferring impacts from the top plate into the flight stack, but it meant that I was just a couple of millimeters short on getting the top plate on my brand new build.

It took more time rearranging the parts and trying difference spacers between the boards to get everything to fit than it did to do the whole rest of the build, or at least that’s what it felt like to me, but in the end I did manage to squeeze everything in. I wasn’t completely happy with the solution but it would do until I could order slightly taller standoffs and longer stack screws.

Building a Quad – Picking the Parts

With the weather warming up I started looking into building a larger sized quad to fly outside. I decided I didn’t want to go straight to a full sized quadcopter with 5″ props which is the standard for FPV freestyle. I wanted to be able to fly comfortably in my yard, so that I could get more time in during the week, rather than always having to go to a field or park. So I settled on a 3″ build plan, because I’d heard that building for smaller props than that wasn’t as good of an experience.

Build a quad from scratch was a daunting experience because of all of the different pieces that needed to be selected and work together. You have to decide on a frame, what size of motors, the camera, the video transmitter (VTX), the receiver, the antennas, the props, the electronic speed controllers (ESCs), and the flight controller. Each component has an impact on the others too. There’s the obvious factor of the weight of the different components versus the thrust that the motors and props will generate, but also just compatibility between the amount of space in the frame for components and the mounting pattern versus the size of the flight controller and other electronics.

I started with the motors and got some advice from some local pilots to look at 1407’s as a good size for flying 3″ props. Then I used a site called RotorBuilds to figure out the rest of the parts list. It’s a site where people post their quadcopter builds. Some with detailed articles and photo albums of the step-by-step and others with just a short description of how it flies. But all of them have a parts list with links to vendors on them. So I ended up searching the site by the size of motors I was looking at building with and getting ideas from that on what parts I was going to buy. One build in particular I ended up being interested in was a 3″ Xilo Phreak because the guy mentioned how durable it was, and I figured as someone just starting out that getting a quad that could handle some hard crashes would be a good idea. I also liked that the Phreak frame had replaceable arms, so I figured in a worse case scenario if I crashed and broke one I wouldn’t have to rebuild the whole baseplate.

For the flight controller, I ended up going with the one mentioned in that RotorBuilds parts list. The HGLRC stack came as a combo with a four-in-one ESC and a VTX so I didn’t have to worry about them working together and the price on the full stack was just a little cheaper than what I’d have spent on separate boards.

When looking at cameras, the major factor in picking one was that I wanted to do HD capture from this quad, and a 3″ build though is too small to carry a GoPro. Plus there was the fact that I didn’t own a GoPro and I didn’t feel like spending a couple hundred dollars to get one. So I had only two choices: a RunCam Split or a Caddx Turtle. Both of these are camera and HD capture board pairs where the camera signal passes through the board first for recording, then goes to the flight controller to get the onscreen display overlay, and lastly goes to the VTX. This allows capturing HD quality video to an SD card on the quad without any analog transmission, but adds some latency to the signal. Latency is a big point of contention among pilots. It is the amount of lag between the camera on the quad capturing an image and that image showing in the pilot’s goggles. Some people seem to be able to notice and be bothered by tiny amounts of latency in that setup, and try to stay away from these types of split capture boards. I’ve never really noticed a problem with it though. I picked the Caddx because it came in black and was a slightly newer design.

The receiver and antennas were that last parts and those were pretty much a given. Since my radio uses the FrSky protocol, and I wanted telemetry on the quad, I only had one option in the R-XSR. For the antennas I had an omni and patch Axii on my goggles already so I got another omni with the same polarization for the quad build.

I was doing all of this near Easter so many of the sites were running sales. I ended up getting most of the parts from GetFpv.com. They didn’t have the receiver in stock though, so I ordered that plus a couple of batteries and a smoke stopper from RaceDayQuads.com. Then I just had to wait for everything to show up.

Here’s the final parts list:

Flying Outside

We had an unusually warm day in February and I seized the opportunity to start flying outside. I briefly tried the back yard but decided it was a bad idea because the tree line there seemed tailor made to snag my drone, and I was scared of getting it stuck high enough I wouldn’t be able to get to it. There were also some low spots in the yard that really held onto water and I really didn’t want to crash into one of those and ruin the quad. The front yard was much better to start out in with less trees. I could use the road, the sidewalks, and fly in the neighbors yards with less chance of bothering anyone.

As much as I’d been looking forward to it, I wasn’t prepared for having to start over again with my comfort level. Beyond the fear of getting stuck somewhere, moving outside posed a whole new set of challenges for me to keep in mind, and I felt like I had when I first started.

My Acrobee only weighs 30 grams with the battery, so I couldn’t fly if there was very much wind. Although I did find that as long as the wind was consistent I could fly in stronger winds than if it was gusting a lot. I could compensate in cases where the wind was consistent, at least up to a certain point.

Once I got comfortable, flying outside really ramped up my excitement in the hobby. After being stuck inside for months, it was a real thrill to be able to get some speed and altitude and try some tricks.

One surprise with flying outside was I reminded that cold weather makes plastic brittle. The whoop frame that I’d been flying for a couple of months started to crack after a few crashes. Initially I tried some super glue, which is my default adhesive for fixing things. It didn’t work well for frame repairs though. It’s too brittle. Repaired spots just broke again after the next impact. Next I tried E6000 adhesive. I’d like to say I did a bunch of research and settled on it, but the truth is I found it in a drawer in the kitchen and decided to try it. E6000 turned out to be perfect for what I needed. It stuck well to the plastic frame and dried to a rubbery consistency so it absorbed impacts pretty well. As a bonus it was easy to clean off of my fingers afterwards.

Despite my best efforts, I did eventually crash into water.

Around Easter time while flying at my Uncle’s house I ended up glancing off a tree branch and crashing into a tiny stream at the back of their property. I could see water at the bottom of the camera lens, so I yanked off my goggles and ran back to get it out of the water and unplug the battery. I was a little panicked but not too badly since the video feed was still active after it hit the water. I figured since it was still transmitting that it should be fine once it dried out.

Once we got home, I decided before I’d plug it back in again I should clean it to make sure that no mineral deposits had been left behind after the water evaporated, which I figured might cause a short. Unfortunately all I had in the house was regular isopropyl alcohol intended for first aid use, which wasn’t pure enough for cleaning electronics. For that I needed 99.9% pure alcohol. So I had to order some and had to wait a few days before I could test to see if the quad was still working or not. Once it came, I took the quad apart and cleaned the flight board top and bottom as well as the back of the camera. I then let them set for an hour to air dry before plugging in a fresh battery to see if it worked. Everything came back up and seemed to be working the same as they had before their water landing. So I got lucky.

I haven’t had any more water accidents since then, and hopefully I don’t, but it was nice to know that I could recover from one. I just don’t want to test my luck on that again.

Repairs and Race Gates

Once I got to the stage where I was flying more than crashing, I started thinking about the next steps which in my mind was getting outside to fly and flying something bigger than a tiny whoop. That left me with two options buy a bigger quad or build one, and I really wanted to build one after going the easier route for the whoop. This meant I needed to get some practice soldering. Preferably on something cheaper than a $10 motor or a $40+ four-in-one ESC board. Which is when I ran across the idea of making a balance charging connector for 1S batteries.

Now you can buy one of these pretty cheaply, I got one from Amazon for less than $9. But that doesn’t get me practice with soldering or using heat shrink and is just not as fun. So I used this forum post I ran across the make one instead. It’s hard to compare the prices since the wire I bought was $7 on it’s own but I barely used any in making this. But the experience in using the soldering iron and the heat gun was well worth it to me.

Most of the soldering done, before the heatshrink was applied.

Basically the batteries are wired in series so that the charge just see’s a single 4S battery in this case. The charge and discharge goes through the XT60 that I soldered on after this picture was taken, while the balance lead has the tree-like wiring to connect the individual batteries together as cells. This allows me to charge 4 1S batteries at the same time, as long as they are all identical type and very close to the same voltage. Which is why I was making a 4S one. I’d already bought a 6S one from Amazon but it meant I couldn’t use it unless I’d flown 6 packs, which some nights I didn’t do.

After that my next foray into soldering wasn’t an optional project. I dropped my radio and snapped of a switch. Not just any switch either but the switch that I’d mapped for arming the quad. Now I did just remap that function to a different switch, but it messed with my muscle memory so it wasn’t going to be a long term solution. So I ordered a new 2 position switch which ran about $5.

This wasn’t actually the first time I’d opened up the radio. When I first got it the left stick which is for throttle and yaw control had a ratchet on it. Which mean that the throttle didn’t move smoothly bit had little stops built into it. I believe this is helpful for RC planes, but it’s not good for quads, so I had already been inside to radio to change it. That time wasn’t too intimidating since I was just adjusting some screws, whereas now I was planning to do some soldering, so I was a bit more worried about screwing something up.

There’s a lot in these devices, but it really wasn’t that bad once I took a little time to look at it. I had to unscrew the old switch from the housing, then remove the heat shrink, and desolder three wires from it. None of which was too bad. The hard part was figuring out the orientation of the new switch since I didn’t think to take pictures of the old one before I removed it. I eventually noticed that the housing and the switch had matching grooves, so that clued me in enough to solder the wires back onto the new switch and put everything back in place correctly. I think the whole operation took me an hour to do, but I’m sure it would’ve taken half that time had I paid more attention to the original wiring and part orientation.

Besides learning to solder and repairing my gear, I also made some race gates. I’d gotten three orange plastic ones for my birthday and they made flying in the house a lot more fun, but I wanted a few more and didn’t want to spend $30 or more on another set. Instead I got an idea from another local pilot who made some gates using poster board and copper pipe fittings.

I made a trip to the local craft supply store for a few sheets of poster board and a couple rolls of duct tape. I already had some scrap 2×4’s and a bunch of dowel rods as well as a hot glue gun. I used the original gates I had gotten as a template for the inside dimension and then I cut six two inch strips of poster board, so I could have double pieces at the top an bottom. The thickness matched up pretty well with the smallest sized dowel that I had, so I was able to make a fork with dowels and scrap wood for the gate to slot into.

Then it was a matter of cutting pieces for the stand’s base, adding some rubber feet so they wouldn’t slide, and cutting some larger diameter dowels for the height I wanted the gate to be. I added duct tape one all four sides at the center line to help find the center of the gate when flying.

I made four of them and had enough supplies for a couple more still. They work great and I got a lot of compliments on them from the guy who’s gates I’d gotten the original idea from.

Here’s a flight from late February where I’m using both the homemade and bought gates in the house. I really got these are the right time as I’d started to get pretty tired of flying inside by this stage. I was really itching for nicer weather to get here so I could start flying outside.

One Month Later

About midway through January my whoop started to failsafe intermittently. That means it would randomly lose connection to my transmitter and as a safety precaution shut off and drop to the ground. This is a safety feature, which isn’t as important for whoops like I’m flying as it is for large quads with say 5″ propellers on them, but even some ones like this can be scary if they were to start whizzing around out of control.

I tried taking it apart and seeing if there was anything obviously damaged but didn’t have any luck. So my next stop was to open a support ticket with NewBeeDrone. They got in touch with me the following day and after submitting some photos they asked me to send it back so they could confirm it was defective and then shipped me a replacement a few days later. The whole process was very painless and pretty speedy.

It also helped that I had a backup quad that I had been waiting to start flying. During the run up to the Christmas season, NewBeeDrone was offering a discount on pre-orders for their replacement to the BeeBrain V2 called the BeeBrain Lite. I felt a little bad placing an order when I already knew I had a V2 coming for Christmas, but only bad enough to leave it in the box until I needed it.

The Lite had a faster processor in the flight controller, integrated video transmitter (VTX) so there was no secondary board, and had LEDs. I also really liked the new canopy that it came with over the V2 version.

I improved a lot during my month between flying my original V2 and my Lite. My normal routine on a week night was to get all of the batteries charged, I’d bought more and was up to a dozen 1S 300mAh LiHV so I could fly for about thirty minutes using all of them, and then once everyone was in bed and I had the house to myself I’d turn on all of the lights on the main floor and go.

I got used to flying with acro mode so the quad wouldn’t automatically level out when I released the sticks. While not super important for what I was doing yet, it was helping me develop better habits with the sticks for when I started trying to do flips and rolls.

I also got much better at planning ahead so I was following a line that I had mapped out through the house. This made my flights smoother, although still restricted by the small space so there were some places where I was basically forced to stop and spin around. But I definitely got a lot of practice flying close to walls and furniture. I actually found it interesting to try to get as low as possible. Something about flying into the kitchen just off the floor and and seeing these huge cabinets come up on either side was quite fun and messed with my sense of scale a little bit. This practice also really helped me with throttle control since I couldn’t afford to lost any altitude on a turn which I was doing a lot when I first started flying.

First Flight

First Flight

After watching NewBeeDrone’s build tutorial video about a dozen times leading up to Christmas, I figured I was covered for putting it together. The kit was pretty easy with no soldering, just a few screws and plugs. It turned out to be a bit harder than I expected though, because of the tiny tiny tiny screws.

I thought I was set for tools, since all I needed was a #000 Phillips screwdriver, but my set wasn’t magnetized which I didn’t realize was something I would want until it was too late. Getting these tiny screws in with only two hands difficult to do. Later on when I looked into getting some magnetized screwdrivers, I found that websites and packaging at hardware stores are very bad about say whether or not they’re magnetized. Which was frustrating until I happened across a magnetizer at Home Depot for $4 and now my existing screwdrivers are fine.

After assembling the Acrobee, I needed to bind it. The kit uses a BeeBrain V2 (now replace by the BeeBrain Lite), which is an all-in-one flight controller, ESC, and receiver. Binding is the process of pairing the receiver on the quad with the transmitter in my radio. Getting the radio into bind mode is easy, just go into the menu on the Taranis and set bind mode. For the receiver though, it involved pressing a tiny button about the size of the screws I’d already struggled with while plugging in a battery at the same time. I eventually discovered a trick for this. I used USB instead of a battery since the BeeBrain powered the receiver off of USB, and it was easier to plug USB into the quad, press the bind button using a screw driver, and then plugging in the USB to the computer one handed.

Once the quad and my radio were talking to one another, I had to get the quad plugged into my computer so I could get it flashed to the latest firmware and configured. This is where Betaflight comes in.

Betaflight is the firmware that runs on the flight controller (FC). The flight controller is the hardware that converts the inputs transmitted from the radio into commands to the electronic speed controllers (ESCs) for the four motors. So when I tell the quad to roll right, the FC determines which motors need to speed up and which need to slow down. It also handles the on-screen display (OSD) which shows things like battery voltage and received signal strength indicator (RSSI) in the FPV goggles.

Of course I couldn’t just plug the quad into the computer USB and have it recognized right away. I need to find some drivers online but that didn’t work either, which is when I went online and found a Bardwell video that walked me through fixing my problem. Just a quick aside, Joshua Bardwell’s YouTube channel and his FPV Know-It-All site have been great for getting into flying FPV quads. Especially for learning Betaflight and troubleshooting issues. Once I finally had Betaflight installed and able to connect to my new Acrobee, the rest of the configuration wasn’t to far off from the NewBeeDrone Betaflight setup video that I’d already watched a few times.

All told, it took me until late in the afternoon on Christmas Day but I eventually got everything put together, configured, and was ready to fly. I was feeling pretty confident. I practiced a bit in a simulator called Liftoff and figured I’d be able to take off and hover no problem. Just the same as with the toy quad I’d started out with.

Maybe it was because the simulator I’d practiced in had me flying outdoors and was simulating a larger quad with 5″ propeller, instead of nano-sized quad with 30mm props, or maybe it’s just a simulator vs real world thing, but I struggled a lot for the first couple of hours to even take off an hover let along zip around the house like I’d imagined.

When I’d give it enough throttle to take off, it would shoot up, and then I’d back of and it would plummet to the floor. I tried a lot of different things that day in adjusting the configuration in Betaflight and doing a lot more research, but I’m not really sure that did much to improve things. I think it just came down to getting enough practice in. Eventually I had enough stick time in that by that evening I was able to get around the house.

Watching that video to put together for this post was a little painful for me. I see so many mistakes now that I didn’t realize at the time. The virtual current meter which is displaying the milliamp hours (mAh) used is totally wrong, and I’ve since gotten used to knowing when to land based on the voltage instead. Flying the battery down to 3.2 volts instead of 3.5 which hurts the lifespan of the battery. Using angle mode (the STAB on the OSD) instead of acro or rate mode. For whoop racers angle mode is actually pretty common, but as someone who was planning to get into larger quads once Sprint came around and do more freestyle flying, it’s a good way to get into some bad habits. Angle mode will level the quad once a stick is released, and doesn’t allow for doing tricks like flips and rolls.

Beyond the software stuff, I really notice now how little planning I’m doing. There’s no line that I’m following as I go around the house, which exacerbates my roughness on the controls and issues with keeping altitude on a turn.

I’ve since realized that I went about this all the hard way, but I really didn’t have much choice given the timing. Starting out indoors is much more difficult than learning to fly outside because there’s more space to make corrections. But given I was learning to fly in the dead of winter when there was quite a bit of snow on the ground, I didn’t have a lot of other options, and I certainly didn’t want to wait for better weather.

Discovering FPV

Discovering FPV

Thing One got a toy drone for his birthday. A simple and inexpensive one with an internal battery and a remote. I helped him get it charged up and ended up flying it more than he did during his birthday. I ordered a second one for myself before the end of the day, and after flying it for about a week I was starting to get frustrated with only being able to fly for about two minutes before having to wait half an hour for it to charge. So of course I headed off to Amazon to find something better.

Father & Son’s First Drones

I hadn’t looked at drone very seriously before then, so all I really knew about them was the high end ones like the ones made by DJI that are intended for aerial photography. The toy quadcopter market had really exploded though, and there were tons of options to research online. Although it didn’t take me long to realize that I wasn’t going to find something with a longer flight time. For the quadcopters that were small enough to fly indoors, battery weight would keep the flight times down to the two minute range. So I needed something with a swappable battery.

Once I knew more about what kind of quadcopter I was looking for, I started searching for reviews on YouTube which is where I stumbled onto the concept of FPV, or first person view. An FPV quadcopter has a camera and a video transmitter (VTX) in it that sends to a pair of goggles that the pilot wears and this allows them to see and fly as though he was inside the quadcopter.

I immediately wanted to do this. I was really taken with the concept of being able to sit in my dining room and fly a quadcopter all over the house without having to follow it around. Even better I could fly around outside and actually be able to get a birds eye view.

My dad has been into RC planes for a few years now, and he’s tried to get me interested in them before, but I’ve never been a fan of flying them line of sight. The plane is tiny and hard to see once it’s up in the air, and I just feel to removed from the experience to have much fun with it. FPV solved all of that, and quadcopters meant I didn’t have to go to a field somewhere but could fly in my house or around my yard.

Eventually I discovered a specific class of micro-drones called Tiny Whoops. This seemed like the perfect entry point for me. They are extremely small and ducted so they’re safe to fly indoors around people and pets. After looking into my options I settled on the NewBeeDrone Acrobee as it was one of the only kits I looked at that didn’t require soldering.

NewBeeDrone Acrobee V2

The next trick of course was getting my wife’s approval, FPV isn’t a cheap hobby to get into. There’s the done itself, which ironically was the cheapest part at about $99. After that I still needed goggles and a transmitter. The goggles can run anywhere from $100 to $600 depending on the style, brand, and receiver options. The transmitters can be as cheap as $50 but I had my eye on one a little more expensive at $200. So even with goggles on the cheaper end of the spectrum I was looking at spending about $500 or so to get into the hobby and I didn’t feel right doing that without talking to her first, especially not in November with the holidays coming up.

Which is how I ended up shopping for myself for Christmas last year. I ordered as Taranis QX7S radio, an Acrobee V2 Kit that included props, a set of batteries, and a pair of EV800D box goggles.

Box goggles aren’t as compact as regular FPV goggles but they’re much less expensive. I got mine for for $109 versus spending $450 for a pair of regular goggles like Fat Sharks where I’d need to spend another $50 to $100 on a receiver module.

The only downside of this plan was waiting for Christmas day to get started, I don’t think I’ve looked forward to a Christmas morning so much since I was in middle school. In the weeks leading up to then I had tried to watch as many videos as I could about assembling the Acrobee, setting up the Taranis radio, and getting them configured to work together. I thought I was pretty well prepared and ready to go, but I found out pretty quickly that I had a lot to learn.