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Old Jan 29, 2010, 11:44 AM
SlingWinger
San Bernardino, California, United States
Joined Oct 2004
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Capacito powered planes, picture posting

I've been having a lot of fun using the 'Air Hogs' capacitor powered geared motor unit in simple free flight models, for several years.

I buy the toy from Target or Walmart for $9 to $12 USD, play with it 'til I get it trimmed (fun challenge), then tear the power plant out and do my own thing. I can get up to 30 second flights, these planes are perfect for a small flying site. Roughly the equivalent of a 12" loop of 1/8" rubber driving a 5 to 7 inch plastic prop, but charging for a flight takes much less time than winding a rubber job.

Anyone else here doing this?

Is there a sticky that might teach me how to get photos from my Sony Handi-Cam up-loaded to this site? I'm extremely computer challenged, it's all I can do to send and receive email and surf these forums. I think the HandiCam takes pixel heavy pictures, so that might preclude me posting pics of my efforts. Still, I'd like to share.

Would I be better off using the camera in my cell phone?

Thanks in advance, Steve
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Old Jan 30, 2010, 10:30 AM
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GerbilEssences's Avatar
Coventry, England
Joined Jan 2009
177 Posts
Ah I thought no one else did this I have through various contrived means aquired 3.3F capacitors and have been fiddling with a selection of motors, yet to try it on my 6mm pager one though. If you ask for a 3F capacitor in the electronics shop they give you a funny look...

Any videos would be greatly appreciated. If you have a handycam I strongly recommend using that footage over mobile phone video. All you need to record off a handycam is Windows Movie Maker (I assume you have?).

I usually whack my videos on to Youtube and then link them into a particular thread, although you can upload straight to this site.

Dave.
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Old Jan 30, 2010, 10:55 AM
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United States, UT, Marysvale
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This looks like fun. Lets see more.
~Vrated
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Old Jan 30, 2010, 07:16 PM
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scrubs's Avatar
Rio Rancho NM
Joined Dec 2004
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www.kenwaymicroflight.com sells the 3.3 F capacitors and his shipping's hard to beat. I've been using the N20 motors, single cell lipos and home made timers ala the Peterborough club. Nearly as cheap, $12-15.

bill
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Old Jan 30, 2010, 10:50 PM
SlingWinger
San Bernardino, California, United States
Joined Oct 2004
1,701 Posts
I don't know how many Farads there are in the Air Hogs capacitor, so I'm assuming that your 3.3's are bigger. Do you know how heavy they are? How much longer would the Air Hog motor run using the 3.3F capacitor?

I have a lot of fun with them, but a bit longer motor run might be nice.
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Old Jan 31, 2010, 07:36 AM
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Coventry, England
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What about using two capacitors at once?
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Old Jan 31, 2010, 08:23 AM
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East Anglia, UK
Joined Sep 2002
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energy in capacitor is 1/2C V^2

so at 10v its 165 joules. or 165 watt seconds.

compared with a LIPO of 3s voltage that's 16.5 amp seconds, or 4.5mAh
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Old Jan 31, 2010, 09:51 AM
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Staffs, UK
Joined Nov 2003
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OTOH you can recharge a capacitor in about 5-10 seconds against an hour or so for a lipo .

And caps are nice because the power delivery more or less matches that of a rubber motor over time, a rapid dash for the ceiling then gradual wind down (I mainly fly FF indoors these days ).

But I haven't played with any for ages. Lipos and timers are so much cheaper these days (certainly if you make your own timers). But I'm tempted, if only I could remember where I put the 4.7F Panasonic supercaps I used to use.

You can certainly parallel capacitors up to roughly double the flight time.

Steve
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Old Jan 31, 2010, 11:16 AM
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East Anglia, UK
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Oh no, I wasn't meaning to slag off caps. Just to put them in context. I agree they are perfect rubber replacement.

To the point where a '3.3F capacitor charged to 12v' would be an ideal competition standard!
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Old Jan 31, 2010, 12:08 PM
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If I remember the reason I got away from caps was the weight roughly the same as a 3 cell 50 mah pack if I remember correctly. On the other hand no fooling with soldering up timers.

bill
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Old Jan 31, 2010, 01:02 PM
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Coventry, England
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Quote:
Originally Posted by slipstick View Post
You can certainly parallel capacitors up to roughly double the flight time.

Steve
Ah, will give this a try. Brutally simple
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Old Jan 31, 2010, 01:27 PM
SlingWinger
San Bernardino, California, United States
Joined Oct 2004
1,701 Posts
Would there be any advantage to charging the cap up to a higher voltage than you want the motor to get, and then run the juice through a resistor to the motor?

Seems like this would allow the fast charge rate that I really like, and then get a longer run time.

I've ruined the Air Hog motors by not allowing sufficient cooling time between flights.
I prefer to go out with three or four planes to fly, that way the motors get to cool and I still get to keep something in the air.
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Old Jan 31, 2010, 07:25 PM
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USA, OK, Muskogee
Joined Nov 2008
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One thing of major note on these caps, the 'super caps' found in many electrical appliances are only rated to 5.5V, or, realistically to <3V. Always have to halve the voltage given on the side. Many are battery backup means and i've been mucking with them for a couple of years. Hand powered LED torches/flashlights work well with them. Put a motor (steppers work best) in line and get that motor shaft spinning with what could be a prop..kinda the opposite of aircraft really
For aircraft useage, i'd guess there must be 25V stamped super caps ? That way, the 3S idea works. I've never seen any rated so high, off now to have a look

Great using them for FF, something i'd been lead to believe was a rubbish idea, but obviously isn't !
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Old Feb 01, 2010, 05:41 AM
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Staffs, UK
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I've never seen any high voltage supercaps either. But since the motors we're using run best on about 4-5V it really doesn't matter. I used to use 3 or 4 sub-C NiCd cells to charge the cap and that worked fine.

There are now loads of small motors which are pretty much designed to work on a single lipo cell (around 4V) so there's a lot more choice than there used to be.

Steve
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Old Feb 01, 2010, 10:02 AM
SlingWinger
San Bernardino, California, United States
Joined Oct 2004
1,701 Posts
So let's say you're motor is good for 6V. If you charge the cap with,say, 12V, and then run the juice through a resistor down to 6V, wouldn't that give more run time? Of course I guess some is lost to heating the resistor?
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