This is a review and build guide for the BeeRotor 160mm from Rctimer.
Overview
Here's some flight-cam video, recorded on my goggles with a HMDVR. BetaFlight's Air Mode is magic.
It hovers at a 1/3 throttle
158g without a battery
Parts
Everything you need except the transmitter and receiver, battery and charger is included in the parts list below. You'll also want some good goggles if you're just getting started.
~$180Here are the parts used in this build. The review section below goes over each component in much more detail, so consider reading on before choosing what parts you want to use in your build.
<img-tr image="/img/blog/beerotor/parts/escs.jpg" text="ESCs: X-Drone 10A - 4x $9.99"></img-tr>
<img-tr image="/img/blog/beerotor/parts/motors.jpg" text="Motors: Rctimer SL1306/3100KV - 2x $19.99 "></img-tr>
<img-tr image="/img/blog/beerotor/parts/props.jpg" text="Props: Gemfan 3x3 - 1x $4.45"></img-tr>
<img-tr image="/img/blog/beerotor/parts/flight-controller.jpg" text="Flight Controller: ACRO OZE32 - 1x $39.99"></img-tr>
<img-tr image="/img/blog/beerotor/parts/camera-vtx.jpg" text="Camera and VTX: ELGAE 127° micro CMOS camera and 200mw VTX - 1x $26.55"></img-tr>
<img-tr image="/img/blog/beerotor/parts/rx.jpg" text="Receiver: Micro OpenLRS from Taobao running SUMD (leave a comment if you know where in the US get these...) - 1x $12"></img-tr>
<img-tr image="/img/blog/beerotor/parts/nylon-m3-bolt.jpg" text="(optional) 8 nylon M3x5mm bolts to hold on the flight controller -- 1x $1.30"></img-tr>
Total QuadCopter Cost: $180.22 + batteries
Unboxing
Here's everything that came in the box:
Batteries
I've been testing with several different batteries, but any 3s battery with a height of less than 25mm and length less than 100mm should work fine.
So far the best size/weight/capacity seems to be in the 900mah range.
The 1500mah barely fits.
Actually, it doesn't really fit, but it can be crammed in there.
Goggles and Transmitter
If you're just getting into this, you'll also need FPV Goggles and a radio control transmitter, the most popular of which among mini-quad pilots is the FrSky Taranis.
HD Camera
I also fly the Xiaomi Yi Camera on this thing, which bright the all up weight to 295g with a 900mah battery.
This go-pro clone looks laughably large on this tiny quad. Even with the camera, it hovers at %50 throttle.
Review
I haven't seen another 150-160mm size frame that can hold a normal 35x35mm flight controller while keeping the battery protected inside the frame. Combined with the OZE32 it is possible to cram give an OSD, current sensor and PDB, plus VTX, RX and Camera all into this awesome little frame and still have room in the body for a battery. Awesome!
It wasn't even that hard to build -- maybe not the best first-project, since everything fits so tightly, but definitely doable with some patience. Just follow the build guide below!
BeeRotor 160mm Frame
Rctimer has release a whole line of new mini-quads dubbed the "BeeRotor" series. This build is the smallest of the available sizes -- 250mm, 210mm, 180mm and 160mm.
It is designed for the battery to sit in the main section and the flight controller to sit below. This is great, as it should allow more mass to sit closer to the center of gravity, making flips and rolls easier.
It comes with two sets of standoffs so you can pick the spacing you want in each section.
Function
Body plates are 1mm and arms are 2mm. Relative to the quad size, these look insanely thick. Given the total mass of the quad, this seems like more than enough carbon fiber to keep the quad intact during a crash.
No rough edges on the carbon fiber, the build quality looks good.
Unlike my Diatone 150mm quad, the motors are exactly symmetrical (even though it doesn't appear so). This is great -- we won't need any custom motor mixes.
The only downside of any frame this small is that it barely fits the Gemfan 3x3 props. I wonder how this thing would fly with arms that could take 4x4.5 props.
I also haven't figured out an efficient way to get the battery into the main compartment. I only had giant Velcro straps sitting around; perhaps some smaller Velcro straps are in order.
Value
Versus a non-carbon fiber frame, it is only $7 more than the cheapest Diatone 160mm frame available, and it is way, way, way more durable.
The durability is totally worth the $6.
Versus other carbon fiber frames, not only is it less expensive than the Diatone Blade 150, the layout is much better, as it protects the battery inside the frame instead of on the bottom. Plus, there is landing gear.
This is the only sub 160mm frame I've seen that has a vibration dampening mount for an HD camera. Surprisingly, it has no trouble lifting the Xiaomi Yi, still hovering at 1/2 throttle.
X-Drone 10A ESCs
X-Drone 10A are re-branded DYS XM10A. According to the manual, these support Damped Light and the switching speed is somewhat fast.
The only downside is that they don't support 4s, so you'll be at a max of 3s on your micro quad. I'm not sure how this will effect performance, but stay tuned for a 4s micro quad build and I'll give you a comparison.
Out of the box, they weigh in at 5g.
Removing the heat shrink and wires, we're down to 2g.
If I built another one of these, I would consider upgrading to xm20a ESCs that support 4S, LittleBee 20A ESCs also support 4S, or the upcoming LittleBee 30A ESCs that will support 6S!
If minimal size and weight are your ultimate goal, checkout Airbot's new 4-in-1 LittleBee ESC. The beta version is a steal at $19.99.
That said, 3S probably makes the most sense. If you do decide to go 4S, you might have to fly smaller batteries as a 3S barely fits in the main compartment.
Rctimer 1306 Motors
The Rctimer SL1306/3100KV motors come with mounting screws, 2mm bullet connectors (which we won't use) and pre-epoxied wires, sweet!
Build quality seems really good, they spin smoothly, bearings feel nice and the magnets are strong.
Spinning them up, one sounds a little chunky, nothing to worry about, but definitely not a perfectly smooth sound. At almost 40,000rpm, this isn't surprising.
Compared to the MayTech 1306 motors I've seen, they're significantly more robust, so hopefully they'll be fairly durable.
I did have to trim down the shrink wrap to get them to lay flat on the arms with the frame legs attached, but better to have too much heat shrink rather than not enough.
OZE32 Flight Controller
I'm a huge fan of the OZE32 all in one flight controller, checkout the OZE32 post for a full review.
Gemfan 3x3 Props
These things are sharp! You can see the translucency in the edge of the prop when held against a light.
After flying "indestructible" DAL props on my 250mm quad for a while, these feel flimsy, but comparing some Diatone 5x3, they're basically the same, just cut down to 3".
Props smaller than 4cm are hard to find, but I have a bunch of 5" props for my 250 size quad sitting around. Checkout Paul's prop cutter if you are in the same situation.
3x3x3 tri-blade props would also be interesting to try, maybe I'll try cutting down some tri-blades...
ELGAE Camera and Video Transmitter
Update Feb 2016: I've been flying the ELGAE camera and video transmitter for a while now and I'm very impressed. In this section, I go on to talk about upgrading the camera. I no longer think this is necessary as the ELGAE camera does great, you probably won't notice much of a difference except at dawn and dusk. I also tried the new "Small" Sony Super HAD camera and it does not fit well. There is however a new camera from Rctimer, which uses the same chipset as the Sony Super HAD (the EFFIO chipset), in an even smaller package and it fits great, albeit with a bit of tilt.
In summary, you shouldn't need to upgrade, but if you do, get the Beerotor Mini camera. Also, if this is your first quad, I suggest you keep the ELGAE camera, since it's the only one that fits without tilt.
Now, back to your regular review.
The transmitter works great. The channel can be changed by pressing a button on the side, which is much easier than flipping dipswitches.
In terms of low light performance and latency, the camera to beat is the Sony Super HAD CCD 600tvl, which survelizone now has in an even smaller 17x17mm package. However, without a video transmitter, this camera is $40.
The Sony Super HAD isn't super high resolution, but it has a super wide dynamic range, making it possible to look straight into the sun and still see the shaded ground. Also, there is no lag, which makes it perfect for FPV.
This is pretty extreme, but here is some footage of the Super HAD at night:
In general CCD cameras have better low-light properties than CMOS cameras. The ELGAE camera however, performs quite well. I took some photos inside with most of the lights turned off and it was very bright.
Usually you see field of view measured by the lens focal length, in millimeters, so for reference a 2.8mm lens has about a 130 degree field of view, which is right in line with this camera.
Note also, that the small Sony Super HAD is the same size, so it should be a drop in replacement for the included CMOS camera, if you ever want to upgrade.
With great performance from the ELGAE set, for less than $30 for both the camera and VTX, this setup is amazing value.
Build
Time to build!
Let's start by prepping the ESCs to attach to the arms.
Arms and ESCs
Take off the shrink wrap. Note to manufacturers, it would be rad if you would send mini-quad ESCs without the shrink wrap and motor leads.
If you want you can leave the signal / servo line soldered on. I'll remove it and solder the OZE32 wire right to the ESC; this way we avoid soldering wire-to-wire which is prone to failure (wire to PCB is always better).
Scrape away the white silicone with a toothpick to expose the servo solder points. Don't use a metal instrument if you value your ESC, as it would be easy to damage the coating on the board with a metal instrument.
De-solder the motor wires. It helps to put a touch of solder on the iron then touch the wire you're removing.
If you have a temperature controlled iron, I like to de-solder at about 750 degrees Fahrenheit.
Here I'm using helping hands, but padding the ESC with a rubber band.
If you don't have helping hands, just tape the ESC down while you de-solder.
Find the M2x6mm bag of screws. We'll use these to attach all of the standoffs.
I'm going to use the M2x14mm standoffs as legs, and the M2x10mm standoffs to hold on the bottom plate. This is possible because the OZE32 doesn't have any vertical pins. It barely fits, mounted upside-down.
Check if your flight controller fits with the 10mm standoffs on the bottom. If it doesn't fit, use the 14mm or 20mm standoffs instead.
My motors wouldn't lay flat with the leg mounted.
So I trimmed back the shrink wrap.
Then cut the motor wires to length, I cut mine to 15mm.
Strip the motor wire leads about 2mm down and tin them. It helps to have a hot iron. 750 degrees Fahrenheit will do the trick.
Solder on the ESC to the motor.
Grab a bag of M2x5mm screws, included with the motors and with thread-lock, attach the motors to the arms.
Frame
Let's build the frame up a bit so we can mount the arms.
Start by mounting the standoffs for the flight controller. I'm using nylon screws, but the included M3x4mm screws will be fine as well.
Attach the standoffs. Put thread lock on all the metal screws. Don't use it on nylon bolts or nylock nuts, as it will corrode the plastic.
I decided to use the 25mm standoffs on the body after checking my battery height.
Camera
Let's install the camera.
The ring only fits on one way.
Put the nut in the side with the hex shaped recess.
Install the camera bracket on the front of the top plate.
Install the camera into the bracket.
Video Transmitter and Camera
Ok, time to wire up the camera and video transmitter (VTX).
Remember that carbon fiber is conductive, so make sure you put some electrical tape or shrink wrap on anything touching the frame. I removed the sticker from the VTX and put a piece of electrical tape over the ground cage.
Let's check the plan the layout of all our components, so we can figure out the lengths to which our wires should be cut. I think mine will fit best like this:
If you were wondering, that's an OpenLRS micro receiver. The only place I've found to get them is straight from the guy who makes them in China. If anyone is interested, I can look into importing a bunch. Email me or leave a comment.
The transmitter included in the ELGAE FOV127 FPV200-set has a LC filter, so we'll wire VCC on the OZE32 to the VTX V+ power in, then power out from the VTX to the camera.
The only other thing that needs to pass through the board is video, so at a minimum, clip the video wire and solder the camera side to the OZE32 VIN and VTX to the VOUT pin.
I don't like soldering wires directly to other wires as these connections tend to break, so instead of cutting down the VTX <-> Camera V+ and GND wire and soldering them together, I removed this resistor on the OZE32, which disconnects the 12v pins on the video headers from the OZE32, but leaves both 12v pins connected together, and soldered both sides to the board. This just allows the power and ground to pass through OZE32, without making any connections to it.
Alternatively, since the camera takes 3.6V to 5.5V, you could take 5v from any 5v output on the OZE32 and send that to the camera. The OZE32 also has a LC filter, so the power will be clean. I'm wiring it the other way since it looks a little prettier, but it might be easier for you to take 5v from an unused serial port like I did on my first OZE32 Build.
You can pull the resistor off easily by heating one side and using a pair of tweeters to pull that side down a bit. Switch sides and repeat to "walk" the resistor off the board.
Check the connection between VCC and the 12v pin with a multi-meter in continuity mode, to make sure that these pins are no longer connected.
I've removed the audio cable, cut the cables to length and soldered all but the power leads onto the board. I'll solder on the power leads when I solder on the ESCs in a minute.
I ended up cutting the camera wires at 55mm and the power leads at 75mm.
Remember when you're soldering, the VTX goes on the pins closest to the edge of the board.
When soldering, tin the wires, flux the pads/holes and then hold the wires in the holes, add a bit of solder to your iron and touch the hole. Solder should flow into the hole filling it up, locking in the wire.
Done!
Flight controller
Before installing the flight controller, I'm going to connect the IMU interrupt pin to the STM32. This will allow us to run a flight control loop sync'd gyro with BetaFlight. This helps increase the copter response by eliminating aliasing in the control loop.
It does require some fine soldering skills and nerves of steel, so weigh the risks against the modest, but not crucial, performance gain.
See the short guide in the OZE32 article to learn how to connect these pins.
Layout
The flight controller seems to fit best upside down. Just make sure you remember to set roll = 180 in CleanFlight. I'll cover this more in the configuration section below.
Another advantage of mounting the OZE32 upside down is that the dipswitches are accessible, with a pin or something long and pointy, from the bottom of the quad.
Measure and cut the ESC signal wire length by holding an arm in place.
I've removed all the extra wires from the JST connector.
The front left ESC needed longer power wires, so I removed these and soldered on longer ones.
Power and Ground
Time to solder all the power and ground connections
-
Battery leads
- I'll use a JST. Tin these wires really well, trying to get as much solder as you can up under the silicon casing, as these wires are prone to fray.
-
VTX power
-
Motors
Here I've soldered the JST connector and the VTX power and ground.
Now the motor leads are soldered.
Do the same for the ground lines on the other side of the board.
Mount the board
Mount the board on the frame then plug in the receiver to the flight controller.
I'll do a quick test to make sure the receiver is working by plugging the OZE32 into my computer and turning on my transmitter and checking the RX tab in CleanFlight.
The receiver tab should look like this if working properly.
I zip-tied on the RX, then I mounted the VTX.
Install the top plate and arms. I started with the un-soldered ESC. Wow that is a tight fit.
Protect the bottom side of each ESC with a piece of tape.
Then tape it on.
In hindsight the ESC with re-soldered power leads looked the cleanest and was the easiest to work with. I might consider un-soldering all the power leads next time, mounting the arms, then soldering them back on the right direction next time.
Test each motor direction by plugging the flight controller into your computer and using the motors tab in the CleanFlight configuration tool. Unsolder from the ESC and swap any two of the three motor leads on motors that rotate the wrong way. Be sure to plug in an antenna to your FPV VTX if it is powered up.
My CCW motors were backwards. After re-soldering, check them again and tape the ESCs down to the arms.
Wow, it's lookin' pretty clean!
Quick camera test, video looks awesome! The picture is super bright, even though the room is dimly lit.
Finally, attach the top plate standoffs.
Then attach the vibration dampening camera mount and screw on in the top plate. Don't forget the thread lock!
Configuration
BlHeli
The Rctimer X-Drone 10A ESCs come pre-flashed with BLHeli 14.0. I like to live on the bleeding edge, so I immediately upgraded them to the latest BlHeli. The defaults will work fine as well. They come with Damped Light turned on, which is really nice. Also PWM is turned off, which means they'll work with BetaFlight no problem.
Be sure to calibrate your escs before you fly.
OZE32
Mine came with CleanFlight 1.10
But BetaFlight is way better, so let's flash that.
Flash BetaFlight
See the OZE32 BetaFlight flashing guide for details.
If you connected the IMU interrupt pin, you'll get a 1khz loop time. Otherwise this will be 1.1khz
Enable your receiver type, current sensor, and set the orientation if you mounted it upside-down (roll = 180).
Make sure you turn on Serial RX on the receiver tab as well.
Tuning
The BetaFlight default PIDs were a little over-tuned, so I turned them down a little. Here is my cleanflight config. Paste it into the CLI and type save then hit enter if you want to use it as a starting point for your config.
The CLI will configure everything, including all the settings in the GUI.
Here is the config: https://gist.github.com/nathantsoi/1fd3bc42977305d1a86d
Note that I was running a 3s 900mah battery while tuning. I suggest getting a more performant battery or upgrading to 4s.
Flash Scarab OSD
See the OZE32 ScarabOSD flashing guide for details.
Be sure to check your failsafe before you fly.
Read the whole pre-flight checklist here.