I measured the motor and the RC transmitter combined, and that came out to 108.1 grams. With the blimp envelope, that comes out to roughly 123 grams.
The length of the blimp is 52". For a diameter, I got approximately 26". The rough volume of the blimp is 10.35 cu. ft. Using pVg, I got a total upward lift of .81 N. The mass allowed for this lift is 83 grams, which is just enough to lift the motor by itself (motor is 79 g).
The 36" balloon would give us an upward lift of 1.55 N, so the new payload would be 159 grams. I did some reading and the 52" x 36"/37" is for higher altitudes. The air is less dense up there, so the mylar balloon will actually hold 2 cubic feet more. This size balloon can hold a maximum of 20 cubic feet of helium. This balloon would be much better at lifting heavier payloads, but we would need a lot more helium. Also, for the amount of lift it gives (about 30 more grams) I don't know if it would be worth it.
The batteries just ran out on the blimp; I'll need our ghetto charger to get it recharged =P
By the way, I still don't quite understand servo controls.
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Something doesn't make sense here Peter. I am happy that the diameter of the balloon is 26"! That makes sense. According to the web site, the balloon only takes 5 cubic feet of helium not the 10.35. We clearly can lift 120 grams, since we can lift both the transmitter and the boarduino board. See if you can figure out the discrepancies.
ReplyDeleteYes, there's something wrong here. I'm not sure you can trust the website specs, but you actually just fill it up with pure helium you'll find that it can carry about 120 grams, above and beyond the envelope itself. You really don't need a bigger envelope--part of the challenge of blimp robotics is picking your electronics well to work within the weight budget you've got, and in this case 120 grams is more than adequate for pretty much anything you want to do.
ReplyDeleteI've commented more on this here:http://diydrones.com/forum/topics/blimp-envelope-payload?page=1&commentId=705844%3AComment%3A56292&x=1#705844Comment56292