Way over-engineered pullcopter v3

I like that you customized the propeller. Most people who print this don't customize anything using OpenSCAD. Your idea for an experiment would be amazing. I think takeoff velocity might be independent of, or even inversely related to flight time in some cases, like a super-lightweight high-pitch propeller may shoot up quickly but stop spinning quickly due to air resistance. I think flight time would be the more relevant measurement. I'm pretty sure that for a given blade aspect ratio and sweep angle, there's a sweet spot combination of blade pitch and ring mass.

I customized a lot, especially clearances to make it work with a poor quality PETG at hand. Clearance check was way too tight with the sub par filament. Saw the scad, went in created a new clearance check kit, that worked good. Generated all parts, worked perfect (even with warping issues)

Best scad delivery i’ve seen.

From my pov, flight time is the thing. for sure.

But 8 year old boys don’t care much about seconds, they are all ‘how high’ :)

Is that silk PLA for the pull cord? Let me know if you have trouble with that; I think PETG would be better.

Yea silk PLA for blade and pull cord, matte PLA for handle. Been working great.

Thanks! Did you print the rotor extra large, or does it look that way due to the wide-angle lens of the camera?

@Anachronist Normal size, probably just the camera, even though it's not even ultrawide (:

@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 - where did those measurements come from? A 56x29 hand seems more like a baby still in the womb, not an 8-year old. I mean, think about it, 29 mm is just over 1 inch in width. I found that a good child-size handle uses the measurements for an average adult female, 171x76.

I have to say that I am pleased that my design managed to accommodate such a tiny handle, and even more surprised that you printed it after seeing it generated. I sure didn't ever check what happens with those parameters.

TPU propellers should work fine if you use a shore hardness above 95a. Even then, the prop blades are thin and would likely still be flexible, so it might require a smooth slow pull to launch it.

Personally I'd worry less about the dog and more about roofs and trees. I have always lost a propeller every time I try to fly this thing.

@Anachronist Definitely good points. This is the site where I found what is supposed to be average hand sizes: https://www.medicalnewstoday.com/articles/average-hand-size#children. I decided to use the difference between your men's and women's size and subtract that again for a child's size. I think it'll be close enough.

I have printed one propeller out of TPU, but it's a toroidal blade I designed using the Ultimate Toroidal Propeller Generator at https://github.com/RaulBejarano/Ultimate-Toroidal-Propeller-Generator. It's a little too light and flimsy, and it doesn't fly nearly as far as your design, which flies like a bat out of hell. (edited)

@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!

@tjsoco - what did you use for the handle? That looks amazingly shiny and smooth. I had some bronze-colored filament similar to that in the past, and it was beautiful, but it didn't have a finish like that.

@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.

@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.