Quadcopter HACK! [Design and Print Your Propeller Guard]




About: Hello There! My name is Timothy and I am 18 years old and I love biking, Rc, arduino ,gadget hacking and 3D designing. I'm currently studying in PATTS College of aeronautic As an incoming 3rd year Avionics s...

Today I will be showing something very interesting especially for those who love flying their quadcopters and doing aerial photography.

THE 3D PRINTED PROP GUARD!......Can also be laser cut

So What is a prop guard??

A Prop guard is something very innovative in a way it protects your quadcopter or your propellers. Removing the risk of hitting someone or something outside or indoors. It is also a cheap accessory that can be printed or cut. I you are aware Of the AR drone it also has prop guards, now what makes it special? Well its because of the hull one for indoor and another for outdoors. It makes things dynamic for the quad right?

Ok so why did i decide to make one?

The dangers of flying a QuadCopter or any other multirotors

First of all flying quadcopters indoor is really dangerous because of the propellers. Hitting someone in the public may cause you serious charges and not only that but you risk destroying your expensive propellers. I know this will come very handy for most aerial photographers out there and If you think prop guards are heavy well think again 4 prop guards only weight aprox. 100g! and that does not really affect your flight does it.

Me as a student Hobbyist

I dont really go out to find some big fields because I have a big house perfect for my quad and a big back yard so why go outside right. I know all parents wont allow their son flying their quadcopters indoor right? So I designed this propguard so that I can play my DJIF450 inside the house or just in my room. And surprisingly when the prop guard arrived from the printing service my parents allowed me and supported me in selling it locally here in the philippines.So to help me mass produce this product here in the Philippines I decided to risk sharing it online to enter this Gadget/Accessorie hacking contest so plss vote/subscribe and hit favorite.

This project was made with the USE of 123D Design

If you have any question or special request PM me I already have tons of prop guard designs

VIDEO Coming soon slow upload here internet problems.....

Step 1: Where to Start?

So to start off you need to remove one of the arms of your quadcopter including the motors mounted.

In the picture I am using a broken motor and a broken DFJI F450 Arm.........

Step 2: Step 1 Lets Begin! Measurements First!

Ok so Now download the 123D design and get a piece of paper, pencil and a ruler or Caliper..."better use caliper" ahem digital.... I want one!

1.on the piece of paper write the radius/ diameter of your motor.........

2.measure the distance between the holes of the motor "screw holes" for my situation the distance was a 16mm and a 19mm in cross form.

3. Measure the Dia. of the motor can and also include the dia. of the bearing

Step 3: Step 2 Arm End Measurements

Now for frame kits like mine this you will need but for must DIY frames out there you might not need to read this step but you might as well read it to give you an idea.

1. Get the diameter/radius of the end part of your quadcopters arm now I will not go to the deep details yet but later on this will serve as your base circle.Going on write down the measurement of this part.

Step 4: Step 3 Propeller Measurement

Now here is an easy step usually there is a label on the propeller you can tell what size it is. In my case I am using a 8"x4.5". Now instead of converting the units grab your ruler and follow the exact measurements in "mm"

Step 5: Modelling Time

So now open up your 123D program

1. Sketch a Circle starting with the biggest circle which is the propeller now type in the diameter and you should have a big circle

2. At the same point enter the diameter from step 3 the "end part of the arm"

3. Now that you have both circles time to use offset

4. Offset the biggest circle by 5-15mm

5. Delete the 2nd biggest circle "The propeller"

Step 6: Lines!

Now we are going to make the boarders of the prop guard

1. Make a line from the center to the end of the largest circle at 20 deg. and at the other side 160 deg.

2.click on that surface and then extrude it by 6-10mm

Step 7: Shell

Now that it is extruded we now make a shell

1. Click on the surface where you want to shell it then set it to outside then thickness of 10mm

2. Go to the bottom view then click on the surface again until it turns blue then click on press/pull.

3. Press it by 10mm then go back again at the top view, you will now see the complete border of the prop guard

Step 8: Base Circle

Now that the shell is complete we now make the base circle

1. Select the center circle and extrude by 5mm "now you have trimmed the unwanted parts"

2 Time to add the center support. If you look at the third image I made a horizontal line that is measuring 8mm at the center of the circle.This will serve a guide line for you to sketch the lines going vertical next. Anyways just look at the picture and do the same thing.

Step 9: Extrude the Support

So now click on the support and extrude it my 6mm again

clean the interior of the base circle and it should look just like the third image

Step 10: Almost Done!

Now the only sketch left is the base circle so we will no extrude it by 4mm.After that we click on the base circle sketch and move it upwards by 4mm placing it at the tom of the solid base circle.

1. We now add a center circle wherein it matches the size of your motors bearing.

2 Remember the arm of the quadcopter well you see most arms have motor hole orientations so we follow it, in my situation from a cross mark we rotate it by 45 deg.So we now make the the cross rotated at 45.

Step 11: Motor Holes

Now Remember the distance of each motor hole we now apply it here

In my case the distance was 16mm and 19mm

1. Make a circle at the center measuring a dia. of 16mm and a 19mm

2.By looking at the image the cross line helps us mark where to place the 3.2mm hole for our 3mm/M3 screws

3. Follow the image and go to the next step

Step 12:

Now delete the unwanted circles and start extruding! and it should look just like the 3rd image

Step 13: Fitting Time

So I got a 3D model of my DJI F450 arm and fitted it guess what fits perfectly

Step 14: Exporting and Printing

Now I hid the unwanted sketches and exported it to .STL file and sent it to our local 3D printing service here in the Philippines -->http://zhaidazz.wix.com/3dprinter

Step 15: Printing

So here is one of the printed prop guards

The print setting will always affect your prop guard in terms of weight and rigidity for now I will not tell the print setting because I actually made prototypes with different print setting to find out what is the best and most suitable for a quadcopter..

Step 16: Screw Screw Screws!

Like i said in the previous step you will be needing M3x12 screws now let me explain why


1st of all the thickness of the arm at the end is 6mm + the thickness of the base circle of the prop guard is 4mm add it together its 10mm /1cm now we need to let 2mm of the screw thread to pass through the screw hole on the motor

thats why 6mm+4mm+2mm = 12mm screw :D

Easy right

So the point here is to know the thickness of the arm where the motor is originally mounted

example you are using a 2mm fiberglass arm for you quad now the base circle of the prop guard is 4mm we just add it all up and 2mm + 4mm + 2mm for the thread and that is 8mm So you will need M3x8 screws

The number of screws will always vary but for me I will need 16 pieces

Step 17: I Cant Find the Proper Screws!

If you can find the proper screw but there are available screw but not the length... It wont hurt buying a cheap wire stripper that comes with a bolt cutter :D

Cut it and do a little sanding on your own

Step 18: Locking Things in Place

So now once you get All 4 of your prop guards remove all old screw bolted onto your motors and and start assembling things and now it should look like my quadcopter :D

I will be uploading a video but for the mean time happy designing and happy flying...ow fly safe with your new prop guard!



    • Arduino Contest 2019

      Arduino Contest 2019
    • Tape Contest

      Tape Contest
    • Trash to Treasure

      Trash to Treasure

    31 Discussions


    Question 1 year ago on Step 15

    Bro which material PLA or ABS


    2 years ago

    Is the stl. file availbale the right size for F450


    3 years ago on Introduction

    hey guys i really like this page but besides this page i found this app that helps you build your own drone in one day check it out https://play.google.com/store/apps/details?id=com.wDIY250QBuild


    3 years ago on Introduction

    Hi, do you have file for SK450 from hobbyking and Lishitoys L6052 for instance?
    really appreciated


    4 years ago on Introduction

    Its perfect. Will you share this .STL file for F450? You will save my time and propellers, too. Thanks

    3 replies

    Reply 4 years ago on Introduction

    You can use this plugin https://extensions.sketchup.com/en/content/sketchup-stl to import stl files into SketchUp


    4 years ago on Introduction

    Hi Tyres,

    This is really great. I just remade it for a customer based on the description above and extended it for slightly longer propellers. I would just like to mention that the downloadable .stl is a little different from the one made by the description (the M3 screw holes are positioned opposite way round ...which we found out was correct in the description but incorrect in the .stl for the drone here). Also the angles are a bit different (10 and 70 degrees). Just to let you know.



    4 years ago on Introduction

    These can be printed using 3DHubs.com and not need the printer.


    4 years ago on Introduction

    A great idea but not having access to hi-tech gear means not everyone can do this. For those less fortunate souls who can't access laser cutters and the like, I use a hot wire cutter I bought to make model parts from styro foam with. I cut up some guards for my 'copter using packing foam and this cutter. In fact I'vecut an entire framework for it. Not as elegant as these guards shown here but they cost nothing and are easily replaced. When I get organised in my retirement I'll post some pics of some of the useful stuff I've made. I'd love a laser cutter incidentally... Anyone got a spare one they don't need?


    4 years ago on Introduction

    Instead of physical bumpers, why not put four ultrasonic proximity sensors (eg PING sensors) around the unit and program the controller to slow down and automatically stop if you find yourself flying towards an object? (I don't know if this is something that is already done in quads but it seems like it could easily be added)


    1 reply

    4 years ago on Step 17

    Helpful tip for shortening bolts (or threaded rod)...
    Wind a nut fully onto the bolt before shearing / sawing / filing the bolt shaft.
    Then afterwards the process of unwinding the nut helps to straighten out and shape any burrs on the the remaining thread.



    4 years ago on Introduction

    ummm- your "100 grams" roughly translates to almost 1/4 Lb which is a lot of extra unnecessary weight , & yes that will affect flight time substantially. Your 450 size multirotor need every bit of extra weight for a GoPro

    1 reply

    Reply 4 years ago on Introduction

    umm it did not really affect the flight time though still at 17min flight time planning to change my battery and prop to get 30 min flight, my friends use 10" prop and 3S while im using 8" 4s battery not really the best combo since this was actually my first quad.


    4 years ago on Introduction

    is it strong enough that you could save some weight by removing the middle support?

    Have you noticed any problems with things that are thin enough to go between the guards (branches, arms, necks) getting caught in there by the blades?

    1 reply

    Reply 4 years ago on Introduction

    since this is an old upload i am now at V4 wherein it will looks kinda the same with the original DJI phantom prop guard with some nylon string surrounding it to avoid things going in between. So yeah there were no problems at all for the weight it can actually be lessen depends on the print setting the 100g i had was set to 50% infill some of my friends tested it in 20-30% they said it was pretty much thesame and cheaper to print.