Remix of the Puller copter toy:

1. Added second gear to double spinning speed, so with the same pulling effort you got more propeller speed
2. Added 3rd wall to the propeller to increase print quality and strength

With these adjustments my 5yo kid is able to launch propeller much higher.

I recommend printing propeller with TPU for durability.

Assembly guide:

1. clean with a knife any harsh parts
2. lube all moving parts
3. place these 2 inserts first

4. Place a small propeller gear

5. place a hub and a shaft 

6. Glue a bumper circle to the big gear and luibe it

7. place a small shaft with short cut down

8. place last insert. Done

After full assemble parts can spin badly, that will be fixed after first couple of launches