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First flight

A project log for Remote Control Mini Blimp!

Mini blimp flies through hoops! Features 3 DC motors/ propellers, battery charging, and wireless communication.

Sophi KravitzSophi Kravitz 12/24/2017 at 02:367 Comments

Tonight I got all the motors working and attached the blimp's gondola to a big purple cube filled with Helium. 

There it is! The blimp sort of hovers and falls at the same time despite the motors turning as fast as they can. You can barely feel any lift from the poor little things! I've bought a lot of motors from random places, so now it's going to be time to figure out the right one with the right propeller.

The motors I'm using pull 230 mA at max speed. The drivers I'm using spec a max of 70 mA, although I'm pulling 110 mA (and no heat, maybe I'm misreading something?). 

I think the main problem is the battery though. It's one cell, 105 mA, so it just doesn't have enough ooomph. I also haven't measured the inrush current yet... could be that it's just killing the battery in one short second.

Next steps:

Discussions

David L Hansen wrote 01/05/2018 at 20:35 point

Given the shape of the balloon (I'm assuming it's pretty spherical or cubic) and the leverage those motors will have around the center of mass, I'll bet most of the energy is going into rotation (culminating in a balanced fight with gravity). To deal with this problem, dirigibles/zeppelins had long cigar/torpedo shapes. My bet is that if you just created another identical motor board you could mount one on the "nose" (wherever you choose that to be) and opposite on its "tail." Then it's balanced and it won't matter that it's spherical. Get them push/pulling the same direction and voila (off to the races)! 

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Paul Andrews wrote 12/24/2017 at 14:16 point

You'll probably figure it out with more experiments. Does the whole thing have neutral buoyancy? It would be fun to see a video. 

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Sophi Kravitz wrote 12/24/2017 at 17:57 point

Yeah there's neutral buoyancy. I'll take a video once it actually lifts!

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Ted Yapo wrote 12/24/2017 at 02:56 point

Are your propellers going the correct (most efficient) way?  I'm not being a wise-guy - the lower motor looks like it's supposed to be doing the lifting, and it's facing downward.  Most toy props I've seen are designed to be pullers, not pushers, and probably aren't very efficient in reverse.

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Sophi Kravitz wrote 12/24/2017 at 17:57 point

Good point, the ONLY reason I designed it to face downwards is just because the toy blimp I bought  has the "lift" motor facing downwards as well. I don't know enough about air flow design yet to comment. 

I def don't feel enough lift coming from the motor I'm using- either it's not powerful enough, or more likely, it's not fast enough. I just ordered a sampling of motors w different rpms and will be experimenting in the coming weeks on both rpm and motor placement! 

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Richard Hogben wrote 12/29/2017 at 22:29 point

You removed and flipped the lower propeller?

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Sophi Kravitz wrote 12/30/2017 at 04:25 point

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