Introduction: Power Distribution for a Multirotor
One of the trickiest things to solve when you're building your own multirotor aircraft is getting power to the ESCs and accessories. My good friend Georges Papabeis clued me into a method using copper clad board that works really well.
- ESCs (I'm building a quadcopter so I have four)
- Pigtails for connecting the battery and accessories
- A short piece of bare 14 gauge solid copper wire
- Copper clad PCB
- Heat shrink tubing
- Soldering Tool
- Dremel with cutting attachment
- Helping hands
- Tabletop vise
- Diagonal cutters
- Wire stripper
- Needlenose pliers
- Heat gun
Step 1: Preparation
You'll need to strip and tin the ends of your wires before you solder them onto the copper board. I stripped the power and accessory leads to about 3mm because they were heavier gauge and I wanted them closer to the edge. I stripped the ESC leads to about 5mm.
Step 2: Cut and Prep the Copper Board
Mark the size you need on your copper board. Because of the dimensions of my frame, I made the strips fairly long. They only need to have enough surface area for your leads. Make sure they are narrow enough to fit inside your heat shrink tubing. You'll be making two sections, one each for the positive and negative leads.
Lock the copper board into the table vise. Don't forget your safety gear! Carefully cut the board with the Dremel tool. I scored the copper surface first to make a straight line and then went back to finish the cut.
Once it is cut, remove any burrs so that you don't have to worry about holes in the heat shrink tubing.
Step 3: Reinforce the Board and Solder the Leads
Cut the 14 gauge conductor to the same length as the copper board sections. Position the conductor along the middle of the board and clamp them both into a clip on your helping hands. Tack a bit of solder onto the ends to hold the wire in place. Remove it from the clamp and then put a bead of solder the length of the wire along the board. I used a pretty generous amount of solder.
The wire helps the power junction handle the high currents that could potentially flow from the battery. Using only the copper board could cause a lot of heat if you punch out during flight. This could damage the connections by ruining the solder joints.
Step 4: Final Assembly
For my build, I soldered the leads for two of the ESCs and one pigtail to each end. Lay out the ESCs in the configuration of your frame and verify the leads all reach to the appropriate places on the power boards. Solder ONE end of the power board with all of the leads that will be on that end. After your solder joints have cooled, cut your heat shrink tubing to length and slide it over the power board all the way to the completed end. Use a clamp from the helping hands to keep the heat shrink out of the way. Solder the remaining leads onto the open end of your power board.
Once the board has cooled, test your connections. After you have verified the connectivity, you should be good to go. Slide the heat shrink tubing into place and hit it with the heat gun to secure your board.