3D printed Drone

Welcome to Polish school 3D printed drone subpage.

This is page is like classroom materials, but maybe little bit more specific and comprehensive topic. That`s why we made it separate page. You can download all printable frame parts and also find parts list that you need to assemble your own drone.

This webpage content:

Drone - drone is a flying robot that can be remotely controlled or fly autonomously using software-controlled flight plans in its embedded systems, that work in conjunction with onboard sensors and a global positioning system (GPS). 

Our drone is simpler, only RC (radio controlled) version. 

Because Drone is flying object, you can use it almost everywhere.  But there are legal rules how and where to fly drone!  Laws for drone flying aren't complicated, but you should know them. For example it is forbidden to fly drones near airports, city centers and highly populated areas. Our drone is without camera, that's why rules are simpler, but it depends on local rules. If you are flying drone in your backyard, then it is ok in every country. If you tune your drone to fly higher and further or maybe it has a camera, you should follow your country drone flying laws!

249g - is magical number in drone world. 250 grams by U.S. Federal Aviation Administration (FAA) is the minimum weight of a drone that needed to be registered for recreational use. Simply said- you dont need to register your drone if it weights less than 250g!

We don't know any drone policemen who wears a weight scale and finds out your drone weight 😊

But we all are engineers and if we have one number to follow, we will do that!

Drone plans and parts below should be right in below 250 grams category. 

Our drone frame is printed from plastic on a 3D printer (PLA/ABS). Frame consists of total seven parts. It took about 12 hours to print all the parts and the material used is about 200g. Unfortunately, due to the fact that the PLA print is less durable than carbon, we increase the thickness of the frame. Our drone benefit compared to carbon frame is, that we can change individual parts not whole frame!

Also you can take it as a challenge- try to design/modify and tune the frame as much as possible. 

Drone frame

The base of the drone consists of two parts, upper and lower. For this, four arms are mounted, in total all 6 parts are screwed together with 16 screws.

On the right is our frame without motors and other equipment. As you can see it is quite simple and straightforward design.

Our drone is FPV drone basic model- for simple words "racing" version 😊

You can tell that drone is sport or stable frame for blade places on the frame. Our drone blades are situating lower/same level as center of gravity- reactions for different movements are faster. But same time drone is little bit "overreacting" - race drone. 

Like fighter planes:

So when designing frames and battery placements, think about that!!

Drone frame printout parts

The top of the frame is mounted by 8 bolts. It maintains the battery and receiver- because then they will balance the center of gravity. Thanks to this, controlling the drone in the air will be easier and more pleasant.

On the right we have four drone arms to for 4 motors and where 4 controllers for individual motors are mounted. 

Drone has built-in support legs so that the drone could land without damaging the electronics.

All drone parts are CAD modelled in Solid edge. 

You can download them in .par files when clicking on the picture on the right and also download .obj files when clicking on the button below the picture.

Like said before, we use PLA as plastic material for frame parts. PLA is quite good material- it´s cheap and durable but negative side is itś  brittleness.

You can use somekind of special filament materials which will make plastic stronger and therefore you can make thinner/less weight parts. 

Parts list for drone

Below is the list of parts needed to purchase for flying drone. Of course you can make modifications and change parts, but be careful- all parts must match with each other. For example battery, receiver and electric motors voltage and so on... You can find more info in ASSEMBLY part of this page. All specs are explained there. 

Many of the parts you can buy in local shops and vendors. Some parts are more specific and you can use e-bay or other webshops for that.

We have added some links for internet shops for various some parts. You can use them as reference data and find most similar parts.

What you need as parts:

You will additionally need some tools:

Like in every machine, you need fastening bolts/nuts  and some cable ties  for easy and fast attatchment.

Overall you need  16 bolts and the lighter the bolts are, the better. ( you can loose weight)

TASK: model a frame that needs less bolts. Maybe somekind of tenon plug?

M3 10mm screws to the frame  and 16 screws for motors

20x nuts 

Cable tie 

Power Board

4 or 3 blade propellers

Flight Controller 

Battery Li-Po 

4x motor brushless motors 

4xESC(Electronic speed control). 

1. Flight Controller

The CopterControl, CC3D and Atom flight controllers are all types of stabilisation hardware which run the OpenPilot firmware. They can be configured to fly any airframe from fixed wing to an octocopter using the OpenPilot Ground Control Station (GCS) software. 

CC3D - flight controller, various versions

As this is going to be our first racing drone, we wanted something easy to assemble and easy to configure. Best for these criterias is  CC3D - preferably in the ATOM version with reduced dimensions. It is quite popular controller with a lot of possibilities and for beginners it is enough. Of course, it is not the only controller possibility- for example Naze32, Flip32, Mini APM are very popular too.

There is one important thing to remember: the flight controllers used in race drones are most often used in manual or acrobatic modes - you can forget about GPS stabilization and perfectly smooth and straight flights.  The idea of racing drones is to maximize the dynamics and the speed of flight therefore any stabilizers will only be in the way. It is worth remembering this fact before we decide to build this type of drone - it is a challenge to steer, but it fully compensates for it with the flight experience when you master it. After you get to know racing drones, then switching to other drones will not make sense, because flights with them will be  too boring! 😊

2. Motors, Regulators and Propellers.

High and Low pitch difference - in simple terms its "how much lift" prop would make. It must be suitable for motor and drone usage conditions.

Motors, regulators and propellers must match. You cannot use too weak engine and too powerful (more thrustful) propeller and vise versa. 

Usually on racing drones due to their the small frames are used small propellers with a diameter of 5 or 6 inches are enough (marking 5 × 3 or6 × 4.5 - "diameter" x "propeller pitch")

For us motors with rating 2200KV is suitable. KV rating in electric motors is like horsepower rating in car engines. It means how much turns motor will make when using constant voltage. 

For example 1800kV motor is "less powerful" than and 2200kV. But it is lighter! So for drones you have to calculate your needs and motors well.

Such motors on small propellers (usually plastic, very light) draw a small current of 5-10A depending on the load, so the most popular speed regulators for racing drones have an efficiency of 12A (12 Amps).

As beginning point the the set: 18XX or 22XX engine + 12A regulator + two-blade propellers, e.g. 5 × 3 is more than enough!

A comment about regulators: they must be designed specifically for drones, have a PWM signal frequency close to 400Hz and special software - most often it is SimonK or BLHeli. Such regulators respond faster to the deflection of our sticks and better synchronize the motors with each other.

3. Battery

There is no big surprise here - like all other quadcopters, also the racing ones are powered by 3S or 4S Li-po batteries. The choice between 3S (3-cell battery) or 4S (4-cell) should be decided at the stage of selecting motors, regulators and propellers. Too powerful battery=more weight and small battery=less fly time.

You should check on which set of propellers the given engine generates the appropriate thrust and whether it is sufficient for us. For beginners who want to learn on this equipment, we recommend Li-po 3S batteries with a capacity of 1300 - 1500mAh. This is the optimal configuration taking into account the weight of the package and the flight time, which is about 10 minutes.


4. Power Board

SmartAP PDB (Power Distribution Board) is a special board which allows transferring the power from the battery to ESCs  and motors and generate power supply for the flight controller and other additional things (camera) with different voltage levels. Also, PDB provides the functionality for battery voltage / current measurements.  It works like extension cord with many power sockets!

There are 3 main points that should be considered when choosing a PDB for your multirotor:

5. Receiver 

This is something that will unfortunately cost the most from the entire kit. At the same time, those of you who already have a different drone or RC model probably have RC equipment with a receiver and they will miss this expense- you can use one controller unit for many different models

The rest of you will unfortunately have to buy your first equipment. For a racing drone, we basically only need 4 channels to support 4 engines, so we can hunt something cheap with this drone in mind only. Personally, we recommend the cheap 6-channel Flysky FS-i6 or its equivalent Turnigy TGY-i6 - it is exactly the same equipment with two different names. The new one is available in the range of 60-80 EURand it has a lot of possibilities - LCD, programmable switches and so on... 

Drone assembling

We start by soldering the black and red cables of each of the 4 regulators to the Power Board - we did it like this: 

Power board with 4 speed controllers.

As you can see then on the power board it is possible to add as many as 8 outputs. We use pads only on opposite sides of the board. 

We soldered like this: 

Move the end of the battery cable to the other side of the power board through a hole in the solder pad and solder with tin on the other side.  

(the set includes two thick wires in silicone insulation + two types of connectors to choose from). We have chosen XT-60 connector due to the fact that most of the batteries are with such a tip. 

As you can see, the main thick power cables are soldered on the other side of the PCB than the controller cables. In our case, it makes sense because we want to mount the power plate on the bottom of the drone in this way:

Battery connection cables are through the board.

Everything soldered looks like this.

Here we have the entire electrical harness of the drone. 

Reciver-control unit-power board-speed controllers-motors.

The cables from the regulators to the CC3D controller were threaded through the center of the power plates. In addition, we put a piece between the power plate and the drone frame of felt cut to the size of the Power Board, and we fastened everything with two zippers.

In the pictures above, you can now clearly see what the main power cord was for - we led it upwards so that it would reach the battery wherever it would be on the frame.

Next, the time has come to assemble the motors according to the scheme:

CW - clockwise.

CCW- counter clockwise.

You need both of them, otherwise drone will spin without control.  

As the set includes left and right engines, we can use them and mount the appropriate engines on the appropriate arms. Each of them is mounted to the frame with miniature screws, which are included in the set (in bags which came with motors, it's easy to lose them!). 

At this stage, however, we need to think about the entire way of mounting the motors and regulators so that the cables are away from the propellers and at the same time do not get tangled somewhere on the frame. We came up with something like this:

Here, however, we encounter a problem when we are connecting motors with regulators - there are no connectors for connecting them in the set. It doesn't seem like a big deal, but the set should include a set of connectors. After much thought about how to connect such miniature motor cables with slightly larger controller cables, we came up with electric cable cubes already proven in another model:

We managed to get the smallest 2.5mm. To reduce the volume even more, we removed the plastic connectors between the individual clamps and cut the tubes a bit with clamping screws, then glued together "individual links" 3 each - using quick-drying glue.

We assembled everything in the following order: 

We realize that such mounting of regulators close to on cables is not the best, because regulators can get hot. However, we hope that their placement outside and the momentum of the air during the flight and from the propellers themselves will cool them well enough. In addition, as you can see, all power is mounted on the bottom of the copter - landing in a water puddle is not an option, because everything can get wet and will short-circuit. We will also think about securing the power board itself with something isolating from water / moisture. 

Through the hole in the lower part of the drone, 4 cables from the regulators and one large power cable for the battery are led out. Now we have to plan and install the electronics:

• battery (800 to 1300mAh recommended)

• RC receiver

• CC3D controller-autopilot + cables connecting with the RC receiver

Drone software settings

Drone control unit needs somekind of software to run motors and speed controllers. For that you can use open source software:

Open pilot (for setting up the drone):

Downloading part is simple- just use install functions and follow instructions.

The last thing is calibrating the drone settings in LibrePilot:

The CC3D flight controller used by the Drone has Open Pilot firmware. We have found that the LibrePilot GCS app has better performance and recommend that it should be installed.

Download the LibrePilot Ground Control Station app (GCS) from 

http://www.librepilot.org/ from the software downloads section.

FLIGHT CONTROLLER SETUP.docx

WARNING: Always remove the props before connecting the flight controller to the GCS

To set up the CC3D flight controller  use your transmitter, you will need:

Open the GCS app and connect the Drone with your mini-USB cable. When the communication window shows that the flight controller is connected to the GCS app, you should see a warning about firmware incompatibility.

Click on the yellow Vehicle Setup Wizard button. Clink on the Next button to open the Firmware Update page. Make sure that the “Erase all settings” box is checked and click on the Upgrade button.

When the update is completed, click on the Next button to open the Board

Identification page. The detected board should be “CopterControl 3D”. Cancel the wizard to return to the Welcome screen.

This means import / retrieve important settings from a stored vehicle template.

Go to the Tools menu > Import / Export Vehicle Template...

On second tab "Import Template".

Select the vehicle template you want and hit the Import button.

Import QAV250 !

If using an S-Bus or DSM type receiver, the receiver cable should be plugged into the Main Port and the appropriate receiver type (S.Bus or DSM) should be selected. When the settings have been changed, click the Save button and cycle the power for the CC3D controller.


Click on the “Save to Board Flash” button to load the file onto the flight controller.

If you have a PWM receiver, no hardware settings will need to be changed. Please go the Flight Controller Input section.

Click on the Input button on the left side of the screen to open the Input settings page.

If your transmitter and receiver have already been setup with the flight controller, this page can be used to test the transmitter controls and switches. The flight battery will have to be connected to power the receiver. 

Warning: Remove the props before connecting the flight battery to the quadcopter.

If any of the channel indicators do not respond to input from the transmitter, click on the “Start Transmitter Setup Wizard” button to configure the flight controller’s input settings.

At the end of the wizard is the screen to set the motor arming procedure. The recommended setting is Yaw Right

which requires the yaw control to be held to the right while the throttle is at 0 for 3 seconds. Holding the Yaw control to the left will disarm the motors. There are several other options available for arming/stopping the motors including using a switch assigned to Channel 6.

After the Arming Setting is selected, the settings need to be saved to the flight controller.

GENERAL SETTINGS

Any time the controller is connected to the app, the following settings should be checked.

Vehicle Configuration Screen:

The Motor Output Channels should have matching Channels


Attitude Configuration Screen:

The Roll, Pitch and Yaw settings should “0”. The Filtering Accelerometer setting should be 0.10.

UPLOADING and DOWNLOADING FLIGHT CONTROLLER SETTINGS

The settings file for the flight controller can be saved or replaced any time the GCS app is opened and connected to the flight controller. 

These functions can be found in the File menu at the upper left corner of the GCS window.

Click on Export UAV Settings to save the current configuration settings of the flight controller.

Click on Import UAV Settings to load a settings file onto the flight controller. If the current settings will be needed in the future, they must be saved before a new file is downloaded.

If you see an entry point error message when either of these procedures is used, click the OK button until a window opens with a folder to save or upload the settings file.

PROPELLERS

Please refer to the diagram when installing or replacing the propellers. When installing propellers, make sure each one is installed on the correct motor. Note that two of the motors shafts and prop nuts are reverse threaded.

CW – Clockwise rotation when viewed from above.

CCW – Counter clockwise rotation when viewed from below.

Checking that all motors are rotation in the correct direction:

If not, swap the two wires going to the motor:

FAILSAFE

If your transmitter can set values for all the channels for failsafe, set the roll and pitch channels to midstick and the throttle to its lowest setting to stop the motors. For transmitters that only set failsafe on the throttle channel, set the throttle to its lowest setting. 

Be sure to remove the props before testing the failsafe operation!

And if everything above is done right you have a chance to make your first flight :)

On the right is our first flight!

Were we happy? Of cource 😊

3d Project_Dron.mp4