OpenWhoop Parametric Micro Racing Multirotor Drone

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OpenWhoop is my attempt at my own "TinyWhoop Like" design for off the shelf common parts. My goal was to make something easily tunable/tweakable via parameters, so I could adjust/dial it in as I crash it and total the frame. Also allowing others to tune it to their parts/needs It's heavily inspired by the "Whoopie" at: https://oscarliang.com/whoopee-micro-frame/ but was designed from scratch in OpenSCAD. I also originally wanted to make a hex with it, so that's designed in. However I struggled to get a hex to fit into my target 110mm wheelbase for the local indoor fpv racing club rules, so I had to drop it to a quad. So the library supports both options. Lastly, I wanted to move the camera out in front, as I had an idea for an integrated single part print, without add-on parts that could support variable angles for the FPV camera, and keep it out in front to keep the rotors out of the view. Designed in OpenSCAD so all you need to do is open the config file, edit the values to your desired parameters (note there are 2 configs, one for quad, one for hex) and then open the QuadFrame or HexFrame scad, render, and export to STL. I printed this in PLA, and Result from the Quad, was a 14g frame all one piece which I added everything else to for an All Up Weight of about 56g before battery. (right now using a much too large battery at 800mah, picking up some smaller batteries to fly with). Even with the 800mah, it's pretty quick, and agile. Flies very well. I included a default STL for both hex and quad. The Quad STL is the one I actually printed, and have flown, and is shown in the pic. The Hex is designed to be smaller, using actual Inductrix props, but on 8.5mm motors (would likely require some persuasion to get the prop onto the slightly larger shaft). I suspect it would perform VERY well. But have yet to pick up the props to try it out. The current build is using the following parts: Hubsan H107d props 8.5mm motor set from HobbyKing Edge Brushed Naze32 Flight Controller from HobbyKing (supports hex brushed motors) Latest BetaFlight 3.x on controller Eachine micro cam/vtx in one Turnigy RX (stripped of it's casing) TGY-IA6C I believe, for a Turnigy Evolution Props were from Amazon Cam/VTX is a standard design from Eachine. I got it at LFS, but should be easy to find. Here are the HobbyKing Part Numbers: Motors - 154000032-0 Flight Controller - 571000106-0 RX - 9114000063-0 Also using a random 800mah battery from LFS, plan on swapping down to a 300mah or lower to reduce weight significantly. Anyway, this is a work in progress, it flies nice, but still needs some work. But I thought I'd release it so that others could try it out, and I could get some feedback/suggestions from the community to improve it. So give it a shot, I'd love to hear your feedback! See below in the custom section for more detailed instructions. If you like the design, let me know, and if you ever need this (or anything else) printed, don't hesitate to check out my hub on 3D Hubs: https://www.3dhubs.com/service/glasswalker Thanks for looking! Print Settings Printer Brand: CEL Printer: CEL Robox Rafts: No Supports: Yes Resolution: 200um Infill: Solid Notes: Printed upside down, in PLA, 200 micron, with support, but no raft. Using a custom profile tweaked to allow more solid printing with thin walls (thinner extrusion width, with tuned flow rate etc). It prints fine otherwise, but I found this resulted in an improved part. How I Designed This Used OpenSCAD to design a library capable of creating the various parts: Camera holder Rotor Ducts/Nacelle Motor Holders Main Frame structures Then setup a couple options for a hex or quad, using a config file to parametrically define motor size, rotor diameter, duct profile settings, camera dimensions, and desired wheelbase of the craft. The library does the rest, and generates an airframe for you. Custom Section Build Instructions Just basically print one of the STL files, only the Quad is tested so-far using the parts above. Or your own parts. Or you can open one of the configs, edit the file for your own dimensions/parts, and export the new STL from the appropriate Frame SCAD file. To Print just print upside down, on 200 micron print size, with support set to 65 degrees. This will support the motor pods, but not put extra support elsewhere. I found setting it lower resulted in "spare" support where I didn't want it. Make sure your printer can handle thin walls. Right now the thinnest wall I believe is 1mm but needs to do that "reliably" Other tips/steps: I used a couple layers of foam tape to adhere the FC to the top of the frame, and the RX to the bottom of the frame, with the antenna whips dangling behind the pods. I also used an extra pair of zipties to hold the battery (left loose so that battery could be slid in and out) For the FPV cam, slide the camera antenna into the notch provided, and then nestle the camera body into the slanted support "socket". This will hold it in place at the right angle. This should leave the button free to push for channel changes, and expose the LED display on the back for easy FPV channel selection. I just used a zip-tie to hold the camera in, the support has 2 notches on the sides on the right angle for a zip-tie or an elastic to hold the camera in. Place Zip Ties around the bottom of the motor holders, and tighten as much as possible. This will "clamp" the motor holders down on the motors, keeping the motors firmly in place. This also keeps the motor holder from softening from heat (PLA not so good at taking heat) from the motors during flight. Config File Instructions For customizing the config file, there are 2 files, one for Hex, one for Quad. Eventually I'll better unify this. motor_diameter is pretty self explanatory motor_clearance is the extra clearance to add to the motor holders around the motor. The motor should easily slide in, but be snug. (it will be tightened with zip-tie) motor_height is the length of the motor. I set this 2mm longer than the actual motor, because then I could tuck the wires from the motor up into the slot and under the zip-tie, which resulted in protecting the wires, and the extra end of the motor holder plastic then acts as landing gear. You could also just cap it with some heat-shrink and use that for landing gear too. motor_mount_gap Is the gap in the motor mount for tightening with a zip-tie, it's the "slit" which faces into the FC. rotor_diameter The diameter of your actual prop rotor_clearance The clearance to provide inside the duct for the prop (note this is not an increase in Radius, it's an increase in total Diameter) rotor_pod_fin_count Number of fins/struts/stators to add to the rotor pod/nacelle. The default is 3, more would be more sturdy, but also impact airflow and weight more. rotor_pod_fin_angle Angle of the stators/fins. This is set to hopefully be optimal to not block airflow, due to the "vortex" created from the rotor. You can adjust the angle to be positive/negative depending on the rotor direction. Default BetaFlight rotor directions are applied with negative angle. If your FC requires reverse rotor rotations, switch to positive number here. rotor_pod_fin_height vertical height of the fins/stators, again more is stronger, but more airflow impact, and weight. duct_flair Duct Flair and curve are 2 parameters I use to calculate the curvature of the intake in the duct. It's not actually spherical, it's an exponential curve. Hard to explain these, so just experiment to find numbers that get the curve profile you like. duct_curve See Duct Flair for more details quad_frame_wheelbase_size This applies to Quad only, and is the desired wheelbase of the quad (diagonal max shaft to shaft distance). I set this based on flying rules at my local club. quad_frame_wheelbase_width For the quad, you can customize it's aspect ratio. Setting the wheelbase size, will always maintain that size, but by adjusting the width manually, you can make it more long/slim, or short,wide etc... hex_frame_wheelbase_size For hex only. For the Hex frame, the wheelbase is "circular" so all pods at same distance. No aspect to customize. This sets the diameter of that "circle" (and respectively the max wheelbase) wall_thickness - Thickness of walls of the duct, etc. Most parts base off of this. motor_wall_thickness - The motor holder and fins/stators use this value instead. Allowed them to be separate so that you could customize strength/weight as you see fit. frame_thickness - This is the Z thickness of the inner frame structure. Note setting this too thin with an aggressive camera angle may result in the camera holder not rendering correctly. (not to mention again, thickness = strength + weight) cam_width - the width of the camera "body" (side to side) cam_length - length (front to back) of the camera body cam_angle - Angle the camera should be tilted at. Positive angle tilts the camera up. Used to set your FPV angle. cam_ant_width - Width of the antenna wire. Used to set the gap/slot for the antenna to fit through cam_loffset_quad - For the quad only, this sets how far forward the camera holder should sit from the center point of the frame. This is used to manually tune where the camera sits. cam_loffset_hex - For hex only. Same as the quad version. Just different value for the hex. $fs & $fa - These are standard OpenSCAD settings for Circle/Arc resolution. FS is size of an arc segment in mm, fa is angular size. These are used to set the "quality" of circles/arcs.