Mini TriCptr KK Mini/1806 motors

thingiverse

Update 23. November 2014: I reinforced the lower part of the front runners by adding an extension. No matter how hard I tried to print them out, they always curled up and created an ugly angled edge when using ABS. This should now be a cleaner job to do, but there may still be some minor curling on the back two rails inside. Cut with a scalpel. Update 21. November 2014: I finally got around to doing a proper maiden flight and filming it. http://youtu.be/CelgFdRE9Kc Update 19. November 2014: I modified the buzzer plug hole position slightly to fit the plug better. Update 16. November 2014: I made some modifications to the landing skids to include slots for 2.5mm wide zip ties, so they wouldn't slip off. Print as-is, with support and an overhang angle of 30°. I also updated the tail. The nut trap was still too large for my taste, which introduced quite a bit of play and allowed the nut to turn when trying to tighten it down. The new nut trap is properly sized for M3 nuts, but can be a bit tight. My slicer added some support inside the hole, so I had to clear out some bits with a sharp knife. If you're having trouble getting the nut to fit, try sticking a long M3 screw into the back of the tail, screw it in a few turns into the nut, then pull the nut firmly into the opening. I modified the canopy. It's shorter at the rear, with a reduced hole at the back and slightly wider ziptie slots to reduce rubbing. I made some changes to this awesome design by Boxx to better suit my setup. I widened the inside space and added standoffs so that a KK Mini board (30.5x30.5mm mounting points) could be installed. I used metal screws to thread the holes, then used nylon screws to secure the KK in place. Since I didn't have any 3mm nylon screws, I used 8mm ones and cut them off at the bottom. I modified the motor mounts to allow me to mount motors with a flat bottom and 2x12+2x16mm motor mounting holes for M2 screws, such as the DYS BE1806 motors. You can still use 4x12mm motors, just with two screws instead – that's still plenty of support. Use washers. I added a hole to the front for a 3mm LED. In my print, it fits snugly with a little push, but you may need to add a drop of hot glue to keep it in place. You can grab 5V for the LED (with a proper resistor) from the ISP port at the front of the KK board to reduce wiring clutter. I added a hole for the buzzer plug, but I'm not sure if it fits – my buzzer is directly soldered to the board. If anyone tests this, let me know please. I uploaded both versions with and without the buzzer plug hole. I modified the tail to open up one side so you can install the motor without having to desolder the wires and lead them through the hole. Also, with the 1806 motors, this was a tight fit in the first place due to their thicker wires. I tweaked the nut trap a bit because it was too wide for my taste – the nyloc nut would spin when trying to tighten the tail down. The new nut trap is properly sized for M3 nuts, but can be a bit tight. My slicer added some support inside the hole, so I had to clear out some bits with a sharp knife. If you're having trouble getting the nut to fit, try sticking a long M3 screw into the back of the tail, screw it in a few turns into the nut, then pull the nut firmly into the opening. I wired the servo and ESCs to lower-profile pinheader sockets to reduce height as much as possible. However, I still use full-size servo plugs for the OrangeRX satellite, so I assume the canopy will fit with standard plugs too. There's a theoretical space for a 3x7x3 bearing on both sides of the tail. The inner one was already there in the original design, but ended up being a little too small in my print. The one on the outside is just meant to give the bearing some extra hold – if they're tight, try adding metal washers on either side. If you find any problems, let me know and I'll try to fix them. Instructions Modified in Sketchup, printed in ABS with 40% infill. AUW with 3S is ~300g. Using DYS BE1806 motors, HQProp 5040 carbon mix propellers, HK Blueseries 12A ESCs with SimonK firmware, KK2 Mini, OrangeRX Spektrum Satellite. I used Cura to slice at 0.2mm for my Mendel90. The tail may need a little support, and the front runners will definitely need support. Print all parts as-is, front skids with support for 30° overhangs.