About a year ago I was looking to get a micro tricopter to fly in the yard. I dont have much space to fly so I needed something small and agile. Tricopters are known for agility, but Micro tricopters weren’t yet offered by the major brands, so my immediate thought was to draw something up in CAD – enter the Micro Tricopter!
When I was designing this, Madelyn was on the way – play time was getting scarce – and something smaller would be easier to fly out in the back yard or even in the living room if I wanted – to satisfy my RC cravings.
All the frames I was interested in, were either too expensive, but mostly too big… So I decided to design my own and take advantage of a local maker space’s 3d printer. But not knowing where to start, I just started measuring all the components with a Micrometer and writing down the dimensions. This is the final design of the servo mount:
The only flight controller that I had at the time was a KK 2.0 board (the mini just came out) and its huge. My goal was to Frankenstein something together with spare parts already in the shop. The “KK2” was the only thing I could come up with – so I started to measure it and knew where the mounting holes were i started to design the main frame. I then measured for the correct angle for the booms, drew and reenforced them.
I wanted to design something durable and forgiving. Flashback to when I was a kid – I had a toy glider that had break-away wings, so when you crashed the wings broke away to absorb the impact and not simply break. This was now the goal, so I didn’t have to keep printing frames when I crashed!
Flite Test uses zip ties on a lot of their designs for various features that may need to be repaired quickly – that was my answer! I designed a socket and plug boom that would be held on with zip ties.
The main feature of the micro tricopter is the break-away booms! When I experience a “hard landing,” I just simply replace the zip tie and I’m back in the air!
On tricopters, the tail boom hinges to provide yaw control, unlike a quad copter that relies on differential torque of adjacent motors. I knew this hinge would be a weak point so I designed something “beefy.”
To come up with the length of the boom I used my finger. Using my pointer finger as a guide I tested it against the length of the prop to make sure the propellers wouldn’t collide during operation.
I ended up making two separate types of booms. A teacup design and a surface mount type for the cross motor mounts.
In the second design the motors are also held on to the frame/ boom with zip ties.
I made the battery tray to protect the battery during hard landings, but it also enabled me to mount some much needed FPV gear.
The battery tray is also held on with zip ties!
The ESC’s, you guessed it – held on with zip ties:
Now I have a fun little tricopter, that is ready to go when I am!
A good friend, Jason, did a great job adapting another flight controller to my design and coming up with his own improvements – like his white zip tie landing skids in place of the battery tray. (Seen in the above video)
If you’d like a list of electronics (that you can discern from the photos) or are interested in getting a frame of your own – comment below. Thanks!
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