Firefly - Printable Racing Drone





Introduction: Firefly - Printable Racing Drone

3D Printing Contest 2016

Runner Up in the
3D Printing Contest 2016

Ever wanted a cool looking 3d Printed racing drone?

With this instructable you can build your own fully featured racing quad with folding arms and superb flight characteristics.You can download all the necessary STL files from thingiverse:

I hope you are having as much fun as I did building and flying it.


For the build you need a whole bunch of screws. Check out the picture for all the details. You will also need dampener balls for the camera plate. You can get them in many different colors and strengths. Choose them depending on the weight of your camera.


For the main frame you will need to print the parts below.

Print the main frame with 25% infill. The sides and bumper are best printed with 50% infill. However the bumper will be heavily penetrated in a crash so you better print a few spares.

Step 3: Starting the Build

Use 4x M3x10MM to secure the bumper together with the lower plate.

The next step ist to attach both sides with 4x M2x10MM screws each.

Step 4: The Arms

The next point on our build list are the arms. You need to print out all the parts below to get startet. And you will also need at least a 400mm long carbon fiber tube with an outer diameter of 12mm.

Step 5: Cutting the Carbon Fiber

To make sure that the motor mount and the arm itself are sitting snuggly in place and are not wobbling arround or twisting we need to drill a few holes in the carbon fiber arm. Therefore we start cutting the carbon fiber tube to a lengh of 100mm each. You can scratch the carbon fiber tube at 100mm and then put it into the jig. Start sawing carefully with a fine metall saw blade while slowly turning the carbon fiber tube.

Step 6: Using the Drill Jig

I made a drill jig because the hole alignment is really important with tubular arms. If the holes are off center your firefly will have jaw issues. To prevent that, make sure that you allign the jigs perfectly flat against their side also make sure you pressed them onto the carbon fiber tubes really hard. If necessary use a hammer.

Now drill two 4mm holes and one 3mm hole. Turn the arm around and drill another 3mm hole. Metal drill bits worked the best for me. When you take the jigs of try to twist them while pulling.

Step 7: Arm Assembly

Now that you prepaired the carbon fiber tubes, its time for the assembly. Clean up the motor mount parts and the hinge very well.

First of all you have to secure the motors on the motor mounts. The motor mounts are designed to take motors with M2 screws. To secure the motors in place take your motor, 1x Motor mount and 1x Motor mount plate stack them onto each other and scew in 2x M2x8MM. Make sure that the motor wires are facing the right side.

Step 8:

The next step is to add the motor mount bottom. Press the motor mount with the motor onto the carbon fiber tube. The pilot holes show the exact position.

Now add the bottom part of the motor mount an secure everything with 4x M2x10MM screws. Screw them in a bit at a time and go slowly. You do not want to break them before your first flight. Now you can add the motor stands. You dont have to screw them in just press them in. Allign the arm hinge with the 3mm holes on the other end of the arm.

Step 9: Clip Lock

To finish the arm mechanism use the 4x M3x10MM in the bumper to screw in 4 clip locks at the front. Use another 4x M3x10MM in the back to do the exact same thing.

Step 10:

Now just clip the arms in place and make sure that the hole for the hinge is alligned with the corresponding hole on the bottom plate.

Now just clip the arms in place and make sure that the hole for the hinge is alligned with the corresponding hole on the bottom plate.

Step 11: Securing the Arms

To secure the arms in place take 4x M3x32MM screws and start screwing them in them in from the lower plate. Once you reached the top plate. Take the M3 washers put them on before you screw on the 4x M3 self locking nuts.

Step 12: FINISH IT

Now just squeeze the bumper balls into the designated holes and install the camera plate.

Now you are done. I hope you have a lot of fun with this little quad. Print out some spare cliplocks, bumpers and motor stands and you should be well equipped for the field.



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@firefly1504 Could you share the solid models of the parts? I am struggling to convert the meshes to usable solids for CAM. :)

Could I have a list of all the supplies and prices? wanting to try and keep this project cheap because im doing it for my schools S.T.E.M. Fair this year and hoping that i can win it!

How are we supposed to secure the electronics? I'm looking at my printed out back plate and I don't see any screw holes.

I upgraded the components list to the new standards.

Flight controller:


With Escs you got 2 different options. If you choose the 4in1 Esc you won't need a pdb anymore since the 4in1 esc has a bec (5V voltage regulator) to power your flight controller.
If you use the slim escs from dys you have to add a PDB to add a voltage regulator and to distribute the power to the escs. Nowadays I would recommend to take the 4in1 it makes a cleaner build, reduces costs and also ist the newer option in terms of performance and software compatibility.

As said if you use the 4 in 1 Esc you don't need the PDB.

Another option if you choose to use the dys escs. A combination of the flight controller with on screen display and PDB. Also makes for a pretty neat build

There are many different flavours of vtxs out there here are some options in different price ranges. In my opinion they all work well.

This is also just an overview. These are products that I have personal experience with and which I can recommend. There are tons of other transmitter and receivers out there but these are in a reasonable price range. I am personally flying the Flysky TH9X with the Frsky XJT module and am very pleased with the overall performance.





Here are a few bits and bobs that you better don't miss out when buying stuff for your quad.
This is some foam padding to put unter your lipo. Maybe put it on your quad with double-sided-tape.

These are just two very different options for lipos. One is more or less the lower price end but still a very good lipo. The smc one is more of there top end in pricing. You can read through tons of lipo reviews and find what you like the most.
Stay in the ballpark of 1300-1500mah and don't choose a lipo that has less then 35C

If you buy stuff over my links it helps me out alot.

Thanks to everybody and happy flying.

Is there any open source programs for integrating to your drone or do you have to write all the program by yourself?

I was wondering if you were considering making a tutorial on building the whole drone, electronics and all. Im new to the hobby and dont know where to really start.

I made a rough parts list with everything to get you up and running:

The motors for your build should have between 2300kv and 2800kv there are a lot of choices out there and its like most of the things in the RC world you have to decide how much money you want to spend.

You will also need ESCs (electronic speed controllers). I recommend going for the xml20a from DYS or similar.

as flightcontroller you'll have a broad variety of choices. You could use a cc3d and then flash beta flight on it which is very cheap, You could also take a look at one of the newer FCs which have integrated OSD (on screen display) and/or video transmitters.
You better make your own decision there.
Different flavours of Flight controllers:
Integrated SD-Card Slot to record flight data:
Integrated OSD:

As PDB (power distribution board) I like the Matek PDB with integrated Lipo warner (Low voltage warner) which also is switchable by the transmitter if you can't find the quad after a crash.
As camera take the 700tvl fatshark camera (because of the size)
I tested a few other cams in similar size and all of them had a very dark picture.
If you choose an FC without video transmitter you can get one of these. They are very small and work great for me (these are also very cheap).

If you want an OSD the micro minimOSD is a very versatile choice. You can monitor your batterie voltage, receiver reception and many more.

Additional parts will be
video goggles,
(This is a hole category in itself but I will leave a few links here)
FIRST CATEGORY: (from expensive to less expensive, and also from better resolution to worse resolution)

SECOND CATEGORY: (Mono-Display-Goggles same order as before)

Things that matter with FPV goggles are FOV(Field of view (higher is better but stay between 30 and 50 degrees for the best flying experience)) and screen resolution (higher is better of cause) and the price.

battery straps,
Get a few 3s Lipos if you are a beginner, but not to many you will be flying 4s sooner as you think. Also do not buy LiPos with a C-Rating lower than 40C.
LiPo charger,
FPV antennas
(Make sure the connector fits your video transmitter (RP-SMA/SMA))

A rule of thumb is don't take the cheapest stuff and start by imitating other fpv pilots.
This is much information for one comment but if you want to build a quadcopter some reading and learning is involved. With the list of products I recommended you have a good starting point for your first build.
If you have any further questions don't hesitate to ask.
Happy flying

This is so helpful. your the best! thanks again.

You are welcome. If you want to support me, vote for me in the 3D printing contest and use my links if you are ordering on bang

That helps me out a lot.