Nerf Nemesis High-Powered Brushless Mod

thingiverse

DOWNLOAD FUSION360 SOURCE FILES: - https://a360.co/2OqjkYe - https://a360.co/2Ir5jFV This is a flywheel cage and flywheels that allow you to turn your Nerf Nemesis from the Nerf Rival series into a brushless driven 480W Monster. ## WARNING: THE CONVERTED NERF RIVAL IS NOT A CHILD-SAFE TOY! THE PROJECTILES CAN CAUSE SERIOUS HARM TO SENSITIVE AREAS. USE RESPONSIBLY AND AT OWN RISK! This design is intended to be printed with an SLA or SLS printer. I used the Anycubic Photon, with a variety of resins. I tried to print this with PLA on my Creality Ender 3, with mixed results. PLA is brittle and the dimensions and physical strength is not optimal for the design. The flywheels are designed to fit 2204 and 2205 brushless motors with a bell diameter of 28mm snugly. Be extra careful when fitting flywheels to motors, any off angle at installation will make the wheel and motor jam up and cause vibrations later on. When selecting brushless ESCs, be certain not to buy the super-fast responding drone or copter ESCs, as they run a different version of the control protocol, and it is difficult to control these with an Arduino. You should pick boring old normal ESCs with a decent amperage, between 20A and 40A. # Parts List You'll need the following electronic parts to complete this mod: - A pair (CW&CCW) of 2204 or 2205 2300KV brushless motors - A pair of 20A or even up to 40A brushless ESCs (Please make sure you use regular ones, not the ones meant for copters or drones.) - An Arduino Uno, Nano, Due, Duemilanove, take your pick. The smallest one that can take 5.5V input is fine, you only need 1 digital in and 2 analog out. - Stepdown voltage regulator that allows to go from 12V to 9V. - A lithium polymer battery 12.4V 3S, about 1300-2600mAh and a compatible battery charger - A battery plug that fits on your lithium polymer battery - 2x 200cm 16AWG wire in red and black - A small roll of thin insulated electrical wire - Shrink tubing - A soldering iron and solder - A dremel or plastic cutting pliers, sandpaper, files # Modifications to Nerf Rival parts - Disassemble your Nerv Rival. You'll need access to the orange flywheel cage. Open it up and remove the part that both motors and flywheels are attached to. - Remove stock flywheels and motors carefully from the part that holds them. - Use a dremel or cutting tool to carefully remove the domes the motors are nested in, and file the walls of these domes down flat. - Look at the underside of that same part and remove the rectangular protrusion that blocks the way of the flywheel cage. # Wiring: - Run positive and negative leads from the battery through thin cable to a step-down, and from there run the positive to the feeder motor, continue from the other connector of the motor to the trigger switch and from there back to the free output connector of the step-down. That completes a 9V circuit with a trigger for the feeder motor. - Run 16AWG positive and negative to the ESCs and connect both in parallel. - Connect ESCs to motors. Switch two of the three wires to change the rotation direction. - Run the negative from both escs as one thin cable to the mass pin of the Arduino. - Run one (and only one!) of the ESCs positive leads to the 5.5V in on the Arduino. That's the power the Arduino runs on. If you connect both ESCs positive leads, one will catch fire, eventually. May take a few hours of usage. - Run both data connectors from the ESCs in parallel, each on its own thin line to one of the PWM outs on the Arduino. # Programming Get the source code: https://github.com/m-hallmann/nemesis-arduino Here's a rough description: - Include Servo.h, connect two appropriate outs to servo.h. Attach the data cable of your brushless ESCs to one out each. Read up on wiring ESCs to Arduinos, and make sure to only connect the positive wire of ONE of both ESCs to the Arduino. Signal and Ground of both need to be connected. - Run a loop that reads one of the digital ins, if it's high, send a maximum value to the two servo outs and of it's low, send a minimum value to the servo outs. That's it. you can get fancy and add a delay timer to the startup routine, as the ESCs have a boot and configuration sequence. If you time that with your watch, it's a good idea to delay the arduino main sequence by a slightly longer period of time so you don't accidentally change the configuration of your ESCs.