Thanks so much for all the kind words, it means a lot!
For folks who are interested in UAV physics, I wrote up an explainer[2].
[1]: https://drive.google.com/file/d/1RTEVRd0XCWLuDXY2nkbmYuOaa5x...
large schedule 40 or 80 tubing sliced into rings would be pretty quick source material, starting with duct tape and zipties until you find a good arrangment then get into the glue and screws.
asking AI "
If we want to ask AI we will.
Some people prefer asking actual people since - especially here - there are experts that can answer that question.
LMGTFY was a snarky and rude answer, but typically led to an actual source. "Here's what AI said" is even ruder because you aren't saying "here's the obvious place to find the actual answer", you are saying "I'm not an expert either, so here's a completely unvetted, but plausible sounding answer"
Just saying to ask AI is the most useless and rudest response of all. It adds nothing. At least pasting the AI response in is an (misguided) attempt at being helpful.
> Some people prefer asking actual people
We all love to do that.
So far those experts have not yet answered. I did. In my experience experts find it rude and tiring to be asked questions if it appears that the questioner hasn't done the basics for themselves. "How To Ask Questions The Smart Way" by Eric S. Raymond and Rick Moen seems relevant: https://archive.ph/duRkf
> Just saying to ask AI is the most useless and rudest response of all
Most definitely rude.
But unfortunately useful.
The AI answer I got appeared plausible to my very basic engineering taste.
It is unfortunately true that AI can give better answers than many HN users.
Obviously AI doesn't usually beat an expert answer.
===
To go meta: is up to Tossrock to become the expert they want by learning the metaskills they need.
I actually thought Tossrock's question was really interesting.
There underlying problem is that we have no polite way to suggest someone try AI. RTFM was historically impolite too.
And posting an AI response (even if filtered and edited) is socially destructive.
FYI: The answer given was something like an outer ring would interfere with lift twice as much, plus that putting weight at rim causes more inertia affecting control. I suspect there's a better question about just using a very fine cable (which would give rigidity without much interference with downdraught). I also suspect that we evolve optimal configurations, and that the underlying reasons are often unclear, and I'm left with too many questions that only an expert could answer.
> But unfortunately useful.
You didn’t answer the question originally and it therefore wasn’t useful at all. All you did was tell them to use AI with an attitude.
If you recognize that it is a rude way to answer, and you add nothing to the conversation, just don’t do it.
How to ask a good question is great knowledge, thanks for the link. How to give a good answer is even more important. Paraphrasing AI as a non expert is an anti-pattern for a good answer. Please stop.
If you can look at your original response and think “everyone would be better off without”, you should not post it.
I've got a question: why CNC milling and not just FDM 3D printed parts? TFA doesn't talk much about it except saying she went to a machine shop.
> 2. CNC milling forms out of G-10 fiberglass (arms) and 5mm carbon fiber (body)
TFA also says this:
> The solution for this is to 3D print a 0-tolerance assembly jig to hold the arms in perfect position while the center of the drone is superglued together.
Why not 3D print it all?
There's this guy who built a drone that can fly for 3 hours and cover hundreds of miles, 3D printed at home on a $250 printer:
Then there was the $200 K quote for the body for a car that just did Pike's Peak with a four times Pike's Peak champion and instead the team... 3D-printed the car's body at home (something like 40 parts, assembled together), which cost them less than $2 K to make (1/100th of the quoted price for the car's body). Here's the vid where they print all the parts (on a $1500 consumer printer):
Basically: why CNC milling and not 3D printing at home when many drones enthusiasts (and now too people building race cars) simply print parts at home on a consumer-grade 3D printer?
Copter-style drones are exposed to vibration across a huge frequency range in every axis, and it's almost impossible to avoid really nasty resonance issues using generally-printable FDM filaments and "standard" design techniques; it's a lot easier to just use super-stiff carbon fiber and CNC it.
For planes, like what you linked, 3D printing is more "plausible" than for copters but also not really practical; you can 3D print a good plane, but plastic lacks the durability and favorable weight characteristics of foam - plastic planes tend to be "one time crashed" while foam is easy to repair, restore, and rebuild.
You'll notice on your 3D printed drone link that the actual multirotor part is carbon fiber tubes. The motor mounts and other brackets can be 3D printed without issues.
To be fair, I definitely did not get good at Fusion in a day (I’m still not very good at Fusion). The Day 1 CAD was all flat shapes -- all I had to do was use the line, curve, and pattern/mirror tools and then extrude those shapes to my body plate / arm thickness. Same with the screw holes -- I didn’t know there was a hole tool and was just drawing circles, patterning them, and extruding them backwards. It still took me forever, I started super early in the morning and worked on it until ~2pm, knowing it would probably take a MechE major 30 mins to do the same thing.
I also do have mentors in the form of eng majors who can give me verbal feedback / advice / show me which tools to use / get me unstuck. To me, it was very important that I was the only one actually doing the CAD so I could learn, but I definitely have had super amazing mentorship along the way to teach me and point me in the right direction. The motors and props are just 3rd-party components that I imported (still took me ages to figure out how to constrain them right). I went to the machine shop after and that took forever too, especially figuring out how I’m supposed to arrange the plates for printing in Fusion (but I had people to help me out there, they were not going to let me use a CNC mill alone with no exp lol)
I made the GPS / receiver mount way later in the process because I was so intimidated by the CAD for it (literally taped my GPS and my receiver to the drone for the first flight instead), and it took me days (also such a simple component, but the stuff that’s not just an extruded 2D shape is way harder for me).
I’m definitely not superhuman and it’s probably going to be years before I feel truly confident in Fusion :))
My first couple days with Fusion had similar outcomes, and this is totally credible. There are extremely talented YouTubers that have information-dense guides through many features. It's totally plausible with that and having a mentor showing you a tool to succeed here.
Why add negativity to something cool? There is a build log! It's well done and tangible! It's not slop! Celebrating is always more fun than humbugging.
Higher end stuff will use a ton of inputs (visual odometry, binocular vision, lidar, range finding, etc) fused into some kind of proprietary blended algorithm that you could probably call an MPC.
RL is pretty cutting edge, especially for fast path motor control; there are a lot of university competitions for drone control that lead to a lot of papers and projects in the space (some promising) but most commercial stuff has not adopted this yet, certainly not at the low end.
And frankly as a pilot, I'd rather not see any completely autonomous drones with no oversight in the sky - that's one incident away in which blame cannot be put solely on the operator from getting the hobby completely banned.
The delta between what is possible with current autonomous flight missions and manual FPV style flight is by having a brain on board that can dynamically adapt to a changing environment. There are a finite amount of PID profiles for each steadystate solution that a researcher can preprepare for. But RL allows an overarching heuristic to transiently alter the PIDs depending on the changing environment.
We use PIDs because analyzing robotics platforms as seeking a steadystate dramatically simplifies the math needed to where its computationally possible for us to solve for a situation.
We use RL in systems that have continuously changing environments with transient solution spaces that are easier to model in hyperspace with a RL model.
Take for example platforms that have tiltrotors. They ideally have a minimum of 3 PID profiles for flying. One when it best fits a multirotor profile. A second when it is transitioning from multirotor to fixed wing flight, and a third for when fixed wing flight is established. What happens when the researcher has a need to fly in the transition state, or subconfigurations of the states? How many PID profiles are you looking to think of and train for? This is where RL has dividends.
I'm sorry for the late response, I didn't realize someone had posted my project
On top of this (Maybe at a few hundred hz), you can add outer controls to set attitude. This could be an autopilot, or having the controls command attitude instead of rate. Betaflight pilots usually don't both with this, and have the simple setup of control maps to rate.
I've programmed firmware using a weird hybrid where the controls command a change in the target attitude. So it flies like rate, but has the forced attitude stability of an attitude-based control system. Non-standard, but makes it so you don't need to worry as much about tuning the PID loop. In practice, you can do full aerobatic flight with this like you'd do with a rate-only setup. (Basically, there is a commanded attitude quaternion; controls nudge it; the PIDs update motor power to maintain this commanded quaternion.)
I've heard the dust from carbon fiber is second to asbestos for inhaling.
Carbon Fiber (and even fibreglass) can make fibres that small and sharp. So yeah, responsible dust handling is key.
The good news is that Asbestos easily puts off those small fibres just by being handled. CF and FG need to be damaged or machined to do it, handling the material after the dust has been dealt with is fine.
Thank you, it's cool!
I did start by designing/building a regular FC (no RL or anything) and am doing RL training afterwards, so I agree that the whole timeline looks a little confusing without background context since it goes real drone --> sim haha
Which also means great people can go beyond what’s their school was about, so a CS major doing CNC isn’t “weird” or different, I remember when applying for jobs in systems in aerospace industry and get rejected despite having a systems background too, with feedback of “they are looking for people with education only in aerospace”, which is idiotic thing to consider.
So good luck OP, start exploring hacking mavlink or similar protocols which is what im working on.
Congratulations --- this is a super cool project. I wonder if you've considered using ultralight filaments and 3dprinting the frame? PLA is stiff but brittle, and I know Bambu and a few others sell specialised versions that supposedly weigh less than normal.
The comments in this thread are overwhelmingly positive by now. Watch out for the contrarian dynamic! (https://hn.algolia.com/?dateRange=all&page=0&prefix=true&que...).
Needlessly negative comments tend to show up first in a thread, while positive responses emerge over time. (Why? well, I have my theories: https://hn.algolia.com/?dateRange=all&page=0&prefix=true&sor...)
It's a fine thing to counteract that with a positive comment, but if you can, please omit the snarky bits (such as in your first paragraph). I know they're tempting, but they tarnish the positivity and substance that you correctly want to see in the discussion - and in the end they "bond" (in the molecular sense) more with the negative posts than with the outright positive ones.
Your second paragraph on its own would make a much better (indeed excellent) post - and that is the best way to combat the negativity.
(I know my reply here is itself an instance of the thing I'm talking about - responding negatively to the negative bits. Sorry!)
Until that happens, this guy here is probably the next best thing: https://www.youtube.com/@MyTechFun
Plot twist: many of the "special" filaments aren't special at all or at least very exaggerated.
https://karolina.mgdubiel.com/drone/drone-img/05-30-26/cnc_c...
The milled fiberglass the author used is a much better UAS frame material than anything from a filament 3d printer due to stiffness and related considerations.
I don't think there's any shame in using LLMs to save time on documenting your projects. Let's be kind and positive to each other!!
You think s/—/--/g is more work than rewriting a whole article? Is this what you're saying?
I'd expect an engineering project with "no prior experience" to take weird/experimental approaches more often compared to a "from scratch" project (where I would expect proven minimalism instead).
The name "octocopter" does not make sense. "Helicopter" is a compound word made of "helico-" and "pter", which means "screw-wings". "Octo-" means eight, "-co-" means nothing.
"Octopter" would be a correct compound word meaning "8-wings", but that would be ambiguous, so the object discussed in TFA is better named just "8-propeller drone".
Multi-rotor drones have been called tricopters, quadcopters, hexacopters, octocopters based on their propeller counts conversationally for as long as I can remember.
There are plenty of commercial vendors who use the exact term for their expensive industrial drones.
Update: I see that in the four minutes it took for me to validate my initial inclination and post that plenty of others also had the same thought :) No need to me to belabor the point!
gyrocopter, helicopter, quadcopter, hexacopter, octocopter, parcelcopter, and—most famously—
roflcopter, https://en.wiktionary.org/wiki/roflcopter#/media/File:Roflco...
They all have their own dictionary entries.
Octocopter makes perfect sense. Everyone understands immediately what it means, and that's the only purpose of language: to convey ideas. It should be clear, which this is, and concise, which this is.
Fidelity to ancient Greek is not, and should not, be a goal for English.
Oh, language changes and now "nit pick" means "to make trivial criticisms" even though neither "nit" nor "pick" etymologically has anything to do with criticisms? How very self-serving of you ;)
A nit pick with your post - you use the word 'ambiguous' but really this is from the latin root 'ambiguus' so we don't need the supurflous 'o' in between the two u's.
