Chaff for detecting thermals? - RC Groups
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Dec 17, 2007, 04:30 PM
There is no spoon
Dax's Avatar

Chaff for detecting thermals?

Ok, so admitidly I don't know what I am talking about, and this is a bit of a stupid idea....

Would it be possible (or helpful) to rig up a "bomb drop" mechnism on a glider that you could release with a 5th channel that would drop a bunch of "chaff" or confetti into the air so you could visualize the thermals in the area? I know it would be littering, which is why its a stupid idea. But would it help? What about using those little parachute men from the dollar store and then collecting them afterwards?

Just a random thought when reading a thermaling article. Feel free to mock me.
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Dec 17, 2007, 04:43 PM
Registered User
It might be very entertaining even if it was not useful for detecting thermals.

For $3 you could adapt this hand powered confetti gun.
This confetti popper gun is great for celebrations and parties. Load up the gun with a confetti bullet and fire in the sky. Shoots a colorful burst of confetti or streamer while making a loud pop. Comes with 5 confetti bullets.

For $49 you could adapt this CO2 powered confetti gun.
This exciting kit packs a punch - capable of shooting streamers 20 feet or more. Small in size, yet powerful. Launcher is only 6" long, great for concealing on stage or makes a great party favor. Dancers, musicians and magicians will find multiple uses for this intriguing effect. This is a small, personal launcher, and does not use lifting cups or backpressure caps. Makes a small burst of confetti around the performer, but not lrge enough for shooting large loads into an audience. Kit includes: Confetti gun, ramming stick, assorted confetti, turbofetti and streamers and 3 Co2 cylinders.
Dec 17, 2007, 04:59 PM
There is no spoon
Dax's Avatar
I just read about using bubble machines to detect thermals, sounds better for the environment. I wonder how I could make a glider mounted bubble maker, lol.
Dec 17, 2007, 05:15 PM
Silent Wings
Oldcoot2's Avatar
Interesting concept! However, if we are going to use this in competition we need to figure out a way to make the chaff visible only to an individual. Hmm, don't you think that would be one heck of a tipoff to a CD when you commence your flight and slip on your Elton John shades?
Dec 17, 2007, 05:56 PM
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Andy W's Avatar
free flight use bubble machines, as mentioned above..
Dec 17, 2007, 06:04 PM
Hot Dawg Glider Pilot
schrederman's Avatar
Oddly, I was thinking about this last night, after hearing of the death of an old soaring (full-scale) friend. He was a real story teller and I was impressed by that when I was a kid. He talked about taking several boxes of Kleenex tissues with him and would continually pull them off and drop them out the window where he thought lift was present. He'd do a 180 and circle where the tissues were going up... Then came variometers...

Dec 17, 2007, 06:24 PM
Registered User
I can see the fun of attaching a bubble machine to my Easy Glider. Just rig up a loop of wire to dip into a tank of soap solution and let the slipstream blow the bubble. But how do we stop it all spilling if we depart from straight and level flight?
Dec 17, 2007, 07:26 PM
Silent Wings
Oldcoot2's Avatar
I have a box of Kleenex and a pair of many teenie weeny tissues do you need, pard? Surely you have another receiver plug open to attach your "Flinger" for dispensing them.

Dec 17, 2007, 07:41 PM
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Norm Furutani's Avatar
Free flighters are all into detecting thermals from the ground.

For visual detection we use:
1. A field of mylar streamers on 20-30ft. poles. VCR tape is OK. The streamers indicate wind direction and intensity. Wind blows toward a thermal.
2. Dry cat tails (plants, not kittys!). They turn into a cloud of fluff and rise with the slightest lift.
3. Bubble machines. use like the cat tails.

Fast acting thermometers (thermisters) indicate the building of heat and signal the release of the thermal by a drop in temp.

The best is to piggy back off someone else. Ultimately, it's knowing how to read your own sailplane.

- Norm
Dec 17, 2007, 08:29 PM
Will fly for food
davidjensen's Avatar
Confetti??? How about smoke generators on the wing tips.
Dec 17, 2007, 09:15 PM
Registered User
At the last free flight contest I went to, a friend of mine was using the dry cat tails to detect thermals. They work. He said he put them in the microwave for a couple of minutes to kill the seeds so they don't germinate later on. I need to google this to see if its true.
Dec 18, 2007, 01:17 AM
I need some building time in t
scaflock's Avatar
LOL I like this thread! It shows me that I'm not the only one here to have really really strange yet oddly practicle ideas!

I think the smoke idea would be the best one at higher altitude as far as visibility goes. The only problem I see with it is a heat source that wouldn't fry your plane. Hummmm..... cold smoke from a chemical reaction of some sort? Come on all you lab rats, help us out on this one.

The confetti idea could also work if you could get reflective confetti so you could see it. Bubbles? Have you ever tried to see small bubbles at high altitude?

OK... I can see that I"m going to have to give this some serious thought and see what I can come up with. LOL I love designing odd-ball stuff.

Dec 18, 2007, 02:21 AM
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Vince inTX.'s Avatar
One possible answer to the "smoke" question is talcum powder. Used in model rockets to keep the parachute from sticking also gives a very nice puff of "smoke" when the chute opens to help spot the plumeting rocket. Eliminates the heat source problem ...but dispensing could be an issue. Then there is the weight........there are some cold chemical reactions that create smoke but it has been a looooooong time since I played with my Junior Chemist chemistry set.

Dec 18, 2007, 02:31 AM
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prodjx's Avatar
Dax, you have to get a copy of Dave Thornberg's Old Buzzard's Soaring Book what many people consider the Bible of model gliding. He even show's an extreamly light parachute using a dry cleaning bag some sewing thread and a penny, I always refer back to it, it's also quite funny. Dave.
Dec 18, 2007, 01:47 PM
B for Bruce
BMatthews's Avatar
Originally Posted by Bark065
At the last free flight contest I went to, a friend of mine was using the dry cat tails to detect thermals. They work. He said he put them in the microwave for a couple of minutes to kill the seeds so they don't germinate later on. I need to google this to see if its true.
I've used dried cattail fluffies quite often. In the areas I use them they are commonly found in the ditches that are wet enough to support them and since those produce more than enough on their own I don't feel guilty at all about blowing a few more up into the air.

The parachute guys are far too heavy to use and you'd need hundreds of them.

What you want would be a big ball of powder or fluffies but good luck seeing it from the ground. Or if you do carry enough of it to see the "cloud" then good luck picking up your model to launch it. A fist sized ejection of powder or fluffies wouldn't be visible for more than a couple of seconds and then it would be gone. It's different at ground level where I use them for finding the thermal that's right over my head or close enough to that. But even there the fluffies dissapear from view by the time they are about 50 to 70 feet away.

Far easier to just learn to concentrate on the model and read the model's response to local air disturbances and thermal. It's passing through the same air that you're suggesting to shoot the fluff or powder out into anyway.

Or find the special 3D thermal imaging thermal detection glasses that you send away 6 cerial boxtops for.... Actually if there was a thermal detecting vision adapter it may just help look for warmer and colder zones in the air. Not sure if such a thing exists though.

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