I wanted to make MikeyB's Crossfire Quadcopter but I have a Thing-O-Matic which only has a 12cm x 12cm print bed. So I sliced MikeB's arms in half and also created a smaller hub which would fit on my printer. So far so good -- perhaps not the most sturdy quad in the world, but that's what epoxy is for. Plus you can just print more pieces if you break them! :)
You will need the following items:
1 Flight control board (KK2.0, Naza, or similar)
4 Brushless motors (I used Turnigy 2836)
4 ESC's suitable for motors (I used HobbyKing F-30A)
12 3.5mm female bullet connectors (if your ESC's don't have them already)
1 multirotor power distribution board (the simple one to solder too, not the ones that have more bullet connectors)
2 feet of 14 gauge multistrand wire: red & black
2 feet of 5mm shrink tube: red and black
1 pair of XT60 connectors
1 3S 3000mah+ Lipo battery (I used Turnigy 3200mah nano)
1 battery strap
4 10x4 props (2 clockwise, 2 counter)
1 Lipo battery charger
1 4 channel minimum, 6 preferred RC Transmitter
1 receiver (usually comes with transmitter)
8 8-32x1.5in Pan head screws
8 8-32x0.75in Pan head screws
16 #8 washers
16 #8 lock washers
16 M3x8mm machine socket cap screws (for motors - make sure they accept M3 mounting screws)
4 M3x8mm machine socket cap screws (for top ring)
16 M3 washers
4 M3x2cm machine socket cap screws
6 inch tiewraps
4 inch tiewraps
two part epoxy
two sided foam tape (thin)
Note: I bought all my RC stuff from Hobbyking and all the fastener hardware from Amazon!
Print 4 of each arm part plus one of each plate and top ring. Use two contrasting colors for the front and back arms which will make it much easier to tell which way your copter is facing.
Note there are two versions of the top plate and ring: one designed for the popular KK2.0 flight control board and the other for the equally popular but much more expensive Naza controller. The pictures show a Naza M Lite version with GPS which is an excellent entry level controller -- very easy for novices to fly because it will hover in place!
Using MikeyB's advice I printed the arms with 50% infill and the plates with 20%.
1. Join the two halves of each arm by first drilling out the hole at the join on the half that holds the motor with a 3mm drill bit. Screw the M3x2cm screw into the enlarged hole until it just pokes out. Using ABS GLUE made from ABS and Acetone ( see http://www.thingiverse.com/thing:14490 ) wet the surfaces to be joined and screw the M3 screw tightly to clamp the parts together. Allow to cure. Note that the ABS glue will work far better than epoxy or any other glue -- it will form a joint that is stronger than the original printed parts!
2. Solder bullet connectors to the motor wires of ESC's -- if this statement is confusing then you need to read up on the whole RC thing, especially RC safety for yourself and others. Here are some good places to start: http://www.rcgroups.com/forums/showthread.php?t=1680372 http://www.rcgroups.com/forums/showthread.php?t=1835014
3. Solder the power wires of ESC's to power distribution board.
4. Solder 5 inches of 14 gauge black and red wire to to the distribution board and solder a male XT60 connector to the other end, shrink-tubing as needed.
5. Figure out which ESCs will go to the front arms and which will go to the back ones. The battery connector wire should go towards the back. Slide the 2 ESC power wires over the hub end of an arm and using the short 8x32 screws attach the top plate to the arm using the 2 inner holes only. Use a washer and lock nut underneath - do not over tighten or the screw heads will deform the plate. The wires go around the arm so that the ESC can sit on top of the arm as pictured. Tie wrap the ESC. Repeat for 3 other arms. Note that you will NOT be using the holes in the top plate! This allows you to replace an arm without desoldering!!
6. If there is any danger of the metal bolts contacting live power on the distribution board, cover the bolts with electrical tape or otherwise insulate the board. Attach the battery strap through the slots and screw on the bottom plate using the long screws making sure that the legs are on the sides so that the battery can sit front to back.
7. Attach the motors using the M3x8mm screws and washers. Route the motor wires connect but don't tie wrap yet.
8. Mount your flight control board and RC receiver and wire appropriately to ESCs. Attach top ring, esp if you are using the Naza GPS.
9. WITHOUT attaching propellers, connect your battery (you may have to solder on the female XT60 connector -- be careful not to short the battery wires while doing this!!!) and configure as a Quad X. Make careful note of the directions each motor is supposed to turn. Test your motors and if they are turning the wrong way swap 2 of the motor wires. Double check. Check again. Now tie wrap the motor wires so they are super neat. Mark in some way which motors turn clockwise and which turn counter.
10. Balance props if you can (even simple balance with a wire). Check out Youtube for this.
11. Attach props, paying careful attention to match prop and motor direction, and fly. Note that if you have never done this before, be incredibly careful and READ lots about RC safety before you try it. In particular, do not connect the battery unless your transmitter is already on. Stay well back. Always disarm the motors before approaching. This is not a toy!!
Builder assumes all responsibility and liability for using these files and instructions! If you are new to RC, read up, watch videos, join a club etc etc... There's a TON of stuff you need to know, and mistakes can end with missing fingers, burned down houses, and worse.
I take no responsibility for any mistakes or inaccuracies in the above! Make and fly at your own risk. (Can you tell I spend a fair share of my life around lawyers?)