So i was looking at some flying robot designs, just out of curiosity. I ruled out helicopters and planes: they require too much precision in crafting and are too complex.. But alternatively an airship could probably be built :)
I've read on wikipedia that a square meter of helium can lift about 1 kg. A square meter means a big balloon, but a Kg is plenty of weight for electonics!
If you use light components, you can probably stay under 0,5 Kg or even less.
For example, some very light battery like this one at 1.1 Ah (only 22 grams!!) or this one at 2Ah, 36 grams.
The airship would probably be too light to effectively fly outdoor, but otherwise it would be nice to have a GPS module and a long-range radio link (this rates at 1,5 Km, not bad), and let it fly :P
There are micro servo that weights 8 grams, the GM10 motors wheight 5 grams.
For the balloon, one of the cheapest way would be to use a condom :P They're strong and light and cheap, the can be inflated to a cilinder that, with some inprecise calculation i did, could host about 0,1 square meter of gas. One could use two or three and have planty of lifting power :)
So the question is: am i completely crazy ?:P
No really, do you think this design could ever work? Of course the best would be to have something that can be controller outdoor, but i think it would be too much..
they would be used to rotate they would be used to rotate the main motors to steer the airship when changing directions… i don’t know if this is the correct way of doing it, i don’t have investigated this deep
i looked around that site… cool, they have nice stuff
The only thing: i could find a “blimp” for outdoor use… they’re all for indoor… Maybe that size is not enought to substain open wind ? Should it be made bigger ?
you could also use a you could also use a solenoid valve to control the amount of helium that gets in/out the baloon, but i’ve only seen heavy ones so far.
A cubic meter is 35.3 cubic feet. I found a party supply site here that sells helium in a small 14.9 cubic foot tank, for $40, so you might need more than 2 if shooting for 1 kg lift capacity. I read that a welding supply would be cheaper (and better quality) to get the helium, but you have the start-up cost of buying a $50-$75 regulator valve.
I’ve thought about the idea too, and considered dangerous (Hydrogen, 4 times the lifting power!) and hot air (huge envelope needed, plus some danger generating the flame).
Due to the shape, they are Due to the shape, they are highly susceptable to light winds. Bigger , heavier and stronger motors would help, but then it gets to be an issue with where to fly it since the altitude is not something that can be easily controlled with these airships outside. I would find this a fairly difficult project, but doable as well…
i have a tank of helium in my workshop. Empty at the moment, but I can recommend this for anyone, it is worth every penny! Making stuff fly & hover in mid air is awesome! I have only made remote controlled blimps though, but that is very very much fun too! (Use inside only, little wind, puff…)
I think I will have to refill soon I hope you make the project Nicola, would be ace to see!
Be aware that ordinary balloons loose the gas very fast (nothing worth the next day-fast) - it seams to just vanish through the material somehow. The sort of blank foil-inside-kind of plastic that you get typical helium balloons in makes it stay much longer, but you will still need refill.
Also, when planing; You should know that these things do not stay in mid air. They follow the air around, even in the most still of rooms, they move around, so you will have to adjust in 6 directions constantly! …hmm … it may actually be quite hard… because you will not know if you are traveling fast, up, down, or still etc. Hmm… 6 SRF05’s or 2 with some serious tilt & pan will be needed!
altimeter i’m not too sure about the horizontal movement detection, maybe some sort of accelerometer, but i was thinking about this idea a little while ago, and found these for altitude sensing perhaps…
I think a simple 3-axis accelerometer would actually be perfect for this task. I don’t yet fully understand when you need to supplement accelerometers with gyros – maybe you’d need a combination of a 3-axis accelerometer and 3 gyros? Either way, it’d still probably be cheaper than 6 SRF05’s This actually sounds like an interesting project – building a blimp that can keep itself locked in one point in space even when wind blows, using fans pointed in all directions. What for? I don’t know. Surveillance maybe – I just like the challenge itself. I’ll come up with an excuse for building it once it works
Uhm it’s going to grow less and less cheap each line i read
Yes, the helium escape becouse its atoms are very small and can pass between the plastic fabric… I’ve read it on wikipedia I don’t know how condoms rate at this… but if i have to guess, given what they’re for, i’d say good
Stabilizing would be a problem… You need extra motors, and with extra motors come extra weight, so bigger balloon etc etc. And IMU sensors are expensive as hell. So i don’t think i’ll be building it anytime soon…
It’s a pity… I was already imagining to fly it to my friends houses via GPS and have live video of them being scared as hell, and then shooting them with the powerful onboard lasers… Well, something like that
PS That pressure sensor looks interesting, it would be a must have for a serious blimp
Three or four separate motors pointing in different directionswith propellers on them would weight the same and be much more versatile than one motor with a servo.
I didn’t really check the site I linked to, I just googled it. But there are several indoor helium blimps available online, I’m sure.
From my experience, the Gyros are very accurate but desperately slow to react. The Accelerometers show change much more quickly, but when you integrate acceleration to get speed, there’s a notable drift. Someone might have a better technical explaination, but I used them in my balancing robot to calibrate each other.
Surely the SRF05s have a very limited range for this type of thing?
I dunno if condoms would work. Helium atoms are very small. Do you have custom condoms for very small things? Ballon material is actually full of holes about the size of helium atoms. Dunno wha the deal is with the metallic stuff. I guess it has fewer or smaller holes or something.
I would go for a combo. A helium ballon to take most of the weight and three upward facing motors on servos. Twisting the motors would allow somplete freedom in 3D. Maneuverability, speed AND a smaller balloon. All good.
Incidentally, there’s no way a metre squared of any gas lifts anything. That would be a metre cubed…
An accel(that thing) "notes" when it is being "moved"
Gyros also drift etc - but this comment is is only about when to use what. If you want to see that "you are being moved", use the accel-thing. If you want to see "where you are", use the gyro.
Example: Make a self-balancing plane. If you use accel-thingeys, when the plane starts it thinks it is pointing downwards due to the acceleration. So use a Gyro for that.
Example: Make a robot that jumps and unfolds itself once it is at the peak of the free air-time. If you use a gyro you can only detect tilt, so use a accellerator… acceler… erh-thingey for that.
