Hi, I'm a 16 years old student and I'm not very good in english, but I'll try to explain to you how I designed and built my quadcopter as best as I can.
Designing a good drone is not an easy task, and it usually takes me 3 different patterns before I make the right and perfect one.
Now that we're done with the talking, let's draw it and print it!
Step 1: Arms
To draw the arms, you need to know wich propeller you use. I used 6050 props on my quadcopter. This means that the propeller measures 6 inches and has a pitch of 5 inches.
With 6050 propellers, the size of the quadcopter needs to be minimum 254mm by 254mm.
The arm needs to be bigger than 63.5mm.
We start the sketch by making a circle for the motor. The motor measures about 30mm of diameter, so I draw a circle with a diameter bigger than the motor. In this case, 50mm looks good.
I have an adapter for the motor, so I measure the distance between the four outside hole and I draw it on the sketch.
Rest of the arms:
After the section for the motor, I draw the center line for the distance, 110mm, longer than the length for the propeller. I added 2 lines to the side with arcs to make it more beautiful! I add other lines to make a square shape inside the arm and double line each lines. Finally , I add another rectancle with 4 holes to connect to the main frame.
I extrude the sketch of 10mm. I already tried 5mm but it's too fragile. Also, I rounded the edges for the look!
Note: If you want a stronger piece, the thickness is more important than the width and the infill.
Step 2: Main Frame
I started by making rough sketches on paper. When I got an idea , I started to think about the dimensions of the frame. The dimensions that I chose are based on the dimensions of the battery and all the electronics. To be able to put all the electronics in it, the main frame will measure 100mm by 250mm.
I start by making the section for the arms in the Step 1. The rectangle measures 40mm by 20mm and they need to be at 45 degres compared to the end. I double all the lines to make the frame. I add 2 rectangles on each sides to connect the landing gear. I extrude of 10mm all the edges and 5mm the rectangles for the arms and the landing gear.
NOTE: My 3D printer can't print the main frame in one piece, so I need to cut it in two and print it in 2 sections.
Step 3: Landing Gear
I start by making a rectangle that I will need to join my two section of the main frame. This piece will go between the landing gear and the main frame. I draw a simple sketch. After that , like all other steps, I double each lines and make a square pattern in the middle of my sketch. I extrude of 10mm. Just enought for support the weight of the quadcopter. I find the center of the top rectangle and make a hole for the srew.
Step 4: Assembly
I start by connect the arm to the main frame with m3 16mm screw. I add the rectangles for additional support. The landing gear after the rectangles. I always use m3 16mm screw in this quadcopter, because all the components are thick.
Step 5: Finally...
I almost finish my first Instructables! It's a lot of work but i'm pretty satisfied. I hope you will be able to design and print your own. If you dont have a 3D printer, is not a problem, it exist a lot of techniques to make a frame. Maybe with wood? Or fiberglass?
I think I have acquire a lot of experience with all the test that I did.
I hope you will like my Instructables! :)