@chrisyue321

Designed a few parts. The holder with 4 flanges is for the ADXL345 accelerometer to measure vibrations. The cylindrical part width the mounting face in the middle is for coupling the steel output shaft with the planetary carrier (I may end up getting it machined as I’m not sure what the strength capabilities of PLA are). The model with the two vertical plates is in progress but it is for the shaft (I did not extrude out the spaces where the bearings would go yet). I am also working on outlining a schematic of the electronics and thinking about starting firmware to gather data. I have a non-assembled devboard lying around that I got a few days ago (from a different project) that I may as well use as the central microcontroller for this project; it should have enough IO pins (if not, no big deal; I have a few IO expanders lying around).

After printing and checking the meshing of the gears, I decided to swap to helical gears as they are more reliable and produce less friction than a herringbone setup despite being slightly weaker and also prone to having the gears slide out of the planetary assembly. I redesigned the shaft clamp design to fit in a smaller size so that I can fit it onto the small shaft of the RS550 DC motor and also changed the gear ratio of the planetary gearbox to be 6. I finished the designs of all of the major motor mounting parts, and printed/verified their functionality with the motor (which just arrived). I have printed the ring gear, the planetary carrier, the 3 planet gears, and the sun gear; however the bearings are yet to arrive so I will not be able to test yet. I also realized that I will need a way to reduce contact surface area of the plastic so as to stop heat from building up, so I will have to reprint the planet gears to have a small notch in the middle that I can glue a small rubber spacer or a nut into.

I conducted some research and eventually decided to implement a planetary gear system to reduce the input RPM for gear testing, as it provides greater strength. I also designed a gear clamp system which allows me to clamp the gears onto the drive shaft reliably with a hex keyway. Below are a few screenshots of the hex keyway system and of the planetary gear system. I am going to conduct a preliminary test print to make sure the gears mesh well, they should mesh fine as my assembly indicates but the tolerances may not work out, or the gears may be too weak, etc.

Built a feature script to auto generate gears which will also be massively helpful in the future during experimentation. Also added some fillets to the front motor mount and two extra front-side mounting holes in case I need extra stability.

I found a motor to use (RS-550, most likely will use th e 18V variant) and designed a mount for the motor which I will most likely 3D print. I also quickly modeled a shaft coupler which I am planning to use

Built a feature script to auto generate gears which will also be massively helpful in the future during experimentation. Also added some fillets to the front motor mount and two extra front-side mounting holes in case I need extra stability.

I built a basic propulsion module but I haven’t gotten around to really implementing it yet I just put in some code to add it into some of the modules but I have not tested it. I’ve mainly been focusing on debugging the dynamics modules as I ran some tests with verbose logging and it appears that there is either something wrong with the calculation of the aerodynamic coefficients or there is something fundamentally wrong with the equations of motion. Here is a screenshot of the erratic behavior (pitch oscillating wildly, roll switching oddly between 0 and 180 degrees, velocity oscillating, altitude behaving weirdly, and all manner of weird stuff.

After starting a new project, I finished implementing V2 of the core data structures, 6DOF equations of motion, and aerodynamic model. I built some unit tests to make sure everything is working properly. Below is an attached screenshot of the test working (I think I may have forgotten to push the testing file to GitHub and only pushed the test functions instead of the file w/ the code that logs the runs)

I found a motor to use (RS-550, most likely will use th e 18V variant) and designed a mount for the motor which I will most likely 3D print. I also quickly modeled a shaft coupler which I am planning to use

I have forgotten to write devlogs on Stardance, I started the project but completely forgot to link my Hackatime. I have been working on the engine on and off for around 3 weeks now. The first version was intended to have a aerodynamic model class with all of the parameters such as coefficient of lift (and its derivatives with respect to variables like angle of attack) among others. However, the dynamics and math appeared to be extremely inconsistent and the simulation as a whole had poor stability. Tweaking the parameters (wingspan, chord, etc) of the wing just slightly caused large fluctuations. I was only able to achieve the stability demonstrated in the screenshots below with an essentially perfectly tuned NACA airfoil. It still does dive a bit more than I was expecting (aka what ChatGPT and Gemini were both expecting since I do not have a lot of extensive experience in aeronautics).

Due to these unresolved issues I have started a new version of the engine which I plan to add a bunch of unit tests to to ensure every module is working as intended, I accidentally overwrote GitHub commit history in the process rip :(.