Way over-engineered pullcopter v3

@NVSteamoji_2130420 - someone told me that paraffin (which is what crayons and candles are made of) attacks PLA but I haven't noticed any problem after years of using paraffin as a dry lubricant for PLA. It doesn't affect PETG either. I use it all the time when I print a bearing that has an axle rotating inside. Works pretty good in gear teeth too.

That looks like the same Prusament blue material I used for mine. Is that what you used?

@Anachronist
Nope, this is some Filamentum filament. The only Prusament I ever had was Galaxy Black.

@tjsoco - thank you. That was an underlying reason for doing this project. I try to avoid designing and printing things that I can buy, unless I can make it better than I can buy.

@ScottA_1512411 - the inertial ring is a balancing act between spinning longer and more weight. I suspect also that maximum flight duration may not necessarily equate to maximum altitude. There are so many variables that can be adjusted with that propeller, experimentally trying to find the optimal combination would involve an unwieldy huge test matrix. The design I ended up with was the result of testing many different configurations, but I have no idea how close it is to being optimal. All I know is that it performs really well.

The blade_hole_offset parameter in that toroidal propeller script just positions the hollow part of the blade inward or outward. Each propeller blade is made by first twisting a solid cylinder around the propeller axis, and then cutting a hole into it by subtracting a smaller twisted cylinder (this is why the cross section isn't an airfoil, it's due to the way it's constructed). You can position the hole inward or outward to make the outer edge of the blade thicker or thinner. Too far outward and the outer edge disappears completely. I don't believe this would affect drag, but it does redistribute the mass. More mass near the center makes the blade stand up better to torque stress from launching, but more mass away from the center gives the propeller more inertia.

@Anachronist I suspected as much. If the blade I made was more than 2mm thick that offset might be of some use, but as it is, it just makes the tips, or the entire blade, disappear.

@EvilleRock_370898 - Thank you so much for the compliment! This design involved a couple of months of work, actually three separate projects (handle, gears, propeller). Be sure to print extra propellers. Every time I fly this, I lose one.
Printables used to show a donation link on my profile, but it seems they don't anymore. You can use https://paypal.me/anachronist if you feel inclined, thanks!

@Anachronist, It is "Polyalchemy Bronze Elixir". I also used an MK4. I purchased it from https://www.printedsolid.com/ 1kg for $25 in Oct 2021, but it seems that they no longer sell it. I save it for special occasions. Alas, I can't find any where to buy it today.

@tjsoco - I just sent a query to Polyalchemy about this. When you run out, the CC3D bronze is a good alternative. I loved it although it was terrible for anything structural. https://www.amazon.com/gp/product/B07FCC3TJG

@MartinRigatoni - I lose a propeller almost every time I fly it. The color doesn't matter, trust me. The propeller seems to be attracted to trees and roofs.

@Luigisvc - what do you mean by "registered"? I haven't heard of such a feature. And thank you for the compliment! (edited)

@Anachronist Sorry, I was refering to my printer model, not your model

@csthomas84 - I printed my pull cord with PLA+, which has additional toughness over PLA. It has held up well. PETG is best however, because PETG is really hard to break.

@Anachronist PETG worked fantastically.

Picture

@RobertHV - Ah, I see. That's a good idea to store them in a filament box. I'll do that with mine now. They're scattered over my desk.

@Rolls17_586768 - making the pull cord from something other than PLA makes it harder to break. PLA+ is pretty tough, and PETG works well also.