Build an RC Blimp for less than $13

Picture of Build an RC Blimp for less than $13
One of the themes in my RC Blimp projects is building them smaller and smaller. First, because I like small things, but also to save on helium.

However, using lightweight RC gear usually raises the build cost. So in this project, I explored hacking a cheap toy RC car (scale 1/64) for the RC gear. It turned out to be fairly simple. One thing was less so: dealing with the very thin gauge copper wire these micro cars use for their magnetic steering actuator. However, for a workshop, I worked out at easier alternative, as shown in the last step.

The cheapest version uses an 11” latex balloon (a common party balloon), well inflated with helium to carry about 10g. The propellers are very simple and made from scratch (See step 5).

The result is small blimp that is suitable to fly at home or in somewhat larger halls. It can even fight some minor air drafts, but as for any small blimp, forget about flying outdoors.

The weight of the blimp is trimmed till it sinks slowly when no power is applied. The main motor pushes it forwards and upwards simultaneously. Dosing the forwards command allows flying at more or less the same level. Steering left and right is done with a tail motor. The controls on these cheap and tiny RC cars is on-off, not proportional. But actually that works better for the blimp than for the cars, as with the blimp you can use its inertia to your advantage.

Flight times easily exceed the driving time of the original Mini Racer used, reaching over 15 minutes.

Here is a video of the blimp flying:
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automaton_be2 months ago

Although you mention a pager motor in the parts list, I don't see it mentioned/used further on. Am I missing something?

masynmachien (author)  automaton_be2 months ago

The "pager" motor becomes the tail motor in step 4.

masynmachien (author) 8 months ago
Thank you!
It brings me great pleasure to read my Ible engaged you to build a blimp too.
Also thanks for sharing the hints. Paperclips are indeed a very suitable alternative to the non hardening clay to trim the buoyancy .
jacksonperrin8 months ago
Thank you for such an engaging instructable--it brought many hours of happy tinkering and experimenting. A couple things that really helped mine: a little $2 propeller from a local hobby shop(as you suggested), a little loop on the belly of the balloon to hang paper clips from: as the balloon loses helium these can be unhooked one at a time--a nice way to gauge remaining flight time. I took mine to a college reunion and floated it over the dance floor to much approval from the dancers.
jacksonperrin8 months ago
Thanks for the great project! I'm still struggling to get mine off the ground. I started with one star-shaped foil balloon filled with helium, volume about 14 liters. When it failed to lift the parts off the ground, I added a second, which also failed to provide enough lift. So I checked to see how many US pennies it would lift: just three, about 8 grams. When I calculate lift based on a density for He of 0.1785 g/L I find that my two balloons should be able to lift almost 30 grams. Any ideas? Does Belgium have super rich He? Is our He being thinned?
oops...brilliant wife informs me that mylar balloons are that heavy. And now I notice your foil balloon is almost a meter long.
masynmachien (author)  jacksonperrin8 months ago
Indeed foil balloons (it actually isn't mylar) are rather heavy. You can check the helium chart from Qualatex (just google) to get an idea.
As surface varies with the power of 2 and volume with the power of 3, the bigger, the easier it gets to achieve enough lift. But with the low power here, keep it under a meter.
And sometimes the helium is less pure (typically in those one way canisters).
higuy1233218 months ago
When I was making mine the back motor wouldn't work any suggestions?
masynmachien (author)  higuy1233218 months ago
Make sure it is well charched with good batteries in the transmitter. In the meanwhile, i learned the back motor quits first on a low battery.

I would first remove the propeller t see if it doesn't hamper the shaft's movement.

if it doesn't help, test the voltage on the leads to the motor (I guess you know how to do that). You should measure a voltage when givving a "turn right" command and an opposite voltage when giving a "turn left" command.

If you have something about 0.6 or more, then the connections are good up to that point and you should check al further connections. Check if the motor runs if you apply like 1.5V to it directly (e.g. from a battery). These tiny motors can be broken.

If you can not measure a voltage ever, male sure that were you soldered you did get to the copper (Do you have experience soldering that kind of wire). The invisable insulating layer should break down with heat, but maybe it did not. You can help establishing contact by sanding the wire ends.

Check the wires to see that they are not broken, but also if they are not short circuited. Don't rely on the invisible insulating wire, it can be damaged.

Making sure there is no short cicuit, measure the vultage on the solder points on the board, where the thin copper wires start. If you do not get any voltage respond to the commands, the board can be damaged. But those boards are quite robust.

Let me know when en how you got it to work. If it doesn't send me some detailed photos.


vincent75208 months ago
You can meet fantastic crazy geniuses only on instructables !!!

Thank you for posting … 

(please give more !)

you made my day !
masynmachien (author)  vincent75208 months ago
Thank you!

You can get such super nice comments only on Instructables!!!

You too, you made my day!

It certainly helps keeping up the work.
snoopindaweb8 months ago
nutley8 months ago
you mentioned building an airplane with these electronics, can you direct me to the plans for it?
masynmachien (author)  nutley8 months ago
It is the same link as mentionned in Step 2:
I will add it when I talking about the actuator too.
Masyn thank you so much holy cow! You are so great!
crazyscottnb8 months ago
CUTE! love the idea how cool woul it be for like hundreds of these things in a hall XD
Decided I'd give this a try today. My plan was more of a zeppelin/airplane hybrid, but definitely in the spirit of the idea. I learned a couple things:

1. Check the battery size of the RC car in question before buying. My car took 3 AA batteries, so there's no chance it's going anywhere.
2. Don't solder in your room of your apartment without first opening a window. Presently airing out my room.
3. Always have spare wire around, whether you think you need it or not. My battery setup is using duct tape and the terminal wire (the springy stuff used to hold the batteries in place).

While getting this to fly is likely going to be unsuccessful, I still had 15$ worth of fun trying this out! Thank you for posting!
zombie_bike8 months ago
awesome idea! I wonder what other ideas you can come up with using those motors..
gdhenson8 months ago
ynze8 months ago
Wonderful hack! I'm gonna make my first blimp with this one this winter :-)
masynmachien (author)  ynze8 months ago
Thanks! Go for it and keep me posted.
Ugifer8 months ago
I have been meaning to try this for years!

Great work - not only did you actually do what I have been meaning to get around to, but you did a much better job than was ever likely to! Lovely job.
masynmachien (author)  Ugifer8 months ago
HrdWodFlor8 months ago
Very cool job. I never would have thought to use those tiny race cars for something like this. Thumbs up!
HrdWodFlor8 months ago
Samuel kos8 months ago
CAT5 cable works well for things like this and it comes pretwisted