More then how long you can stay in the air ...
It is about ... how far your RC bird can go.
The "TAM-5" did a massive 1,881.6 mi (3,028.1 km) ... on a single ... fuel load :black_eyed: ...
Longest Flight time
- Thread starter Wojethebest
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More then how long you can stay in the air ...
It is about ... how far your RC bird can go.
The "TAM-5" did a massive 1,881.6 mi (3,028.1 km) ... on a single ... fuel load :black_eyed: ...
stay-fun
Helicopter addict
It is a bit of a weird rule: "no gliders". Well, just make something with a fairly large wingspan, and low wing loading. No it's not a glider, it's just a plane with large wing span!
Anyhow, apart from that it's all about weight. Go for a small motor and small prop (make sure the motor doesn't get hot in flight), and make sure you don't need a lot of power to keep it in the air. Further, choose an ESC with 'active freewheeling' (such as Kontronik, YGE or the hobbyking YEP ESC's), this will reduce power losses at partial throttle. If you can, change the PWM of the ESC to the lowest frequency to further minimize losses. And have an ESC with switching BEC, which are more efficient than linear BECs. Additionally, run the BEC at only 5V, and use analog servos.
About active freewheeling, look at this thread:
http://www.helifreak.com/showpost.php?p=4210229&postcount=3
Anyhow, apart from that it's all about weight. Go for a small motor and small prop (make sure the motor doesn't get hot in flight), and make sure you don't need a lot of power to keep it in the air. Further, choose an ESC with 'active freewheeling' (such as Kontronik, YGE or the hobbyking YEP ESC's), this will reduce power losses at partial throttle. If you can, change the PWM of the ESC to the lowest frequency to further minimize losses. And have an ESC with switching BEC, which are more efficient than linear BECs. Additionally, run the BEC at only 5V, and use analog servos.
About active freewheeling, look at this thread:
http://www.helifreak.com/showpost.php?p=4210229&postcount=3
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rcspaceflight
creator of virtual planes
Can I just tie a light plane to the ground on a windy day and fly it like a kite? With the right weather and right location I could probably keep it in the air for a week. ... I'm done being a smarty.
Wojethebest
Junior Member
The reason is i wanted to make this a competition of reducing drag and increasing efficiency of electronics.
If you want to do a glider challenge we can make one
stay-fun
Helicopter addict
Fair enough, but when is a plane a glider and when is it not? At a certain wing loading? Wing span vs weight?
Is not only about glider vs no glider (that is already impossible to define which bird is a glider and which is not).
But what about people that can use thermals ? These can stay in the air for ever.
There are already competition for gliders ... but more then the motor efficiency , the rule is about who can stay longer in the air without motor off, after the bird has reach X meters of altitude
If you want to make a competition about efficiency ... it should not be about how long, but about how far a bird can go
Using only fly over a flat land .. not near mountains or any slope place ... in these case is possible to see which is the most efficient electro RC bird.
I guess the record back in 2003 done with 3.5L of fuel ... is unbeatable for a electro bird even using solar panels ... but it could be already interesting to see if anybody can make 100km distance with a 2200mAh 3S pack
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rcspaceflight
creator of virtual planes
Make it an indoor competition.
Freaky_1
old headcase
Short of putting it inside a building and packing a 2200, I think rcspace has already won that one with the EDFogey
rcspaceflight
creator of virtual planes
Short of putting it inside a building and packing a 2200, I think rcspace has already won that one with the EDFogey
I actually flew the EDFogey with a 3S 2200mah battery. It flew horribly, but it flew. But I don't think it would fly for very long. Maybe 10 minutes.
Freaky_1
old headcase
Lol but it would fly rather than hover or just bang the walls
rcspaceflight
creator of virtual planes
On a serious note, I have this battery in my Tx. It's a very low C rated 2200mah 3S battery and it weighs 137grams. As compared to the 2200mah 3S battery that I power planes with that weighs 190grams.
Yes, 1.5 is an extremely low C rating. But if you want the plane to fly as long as possible, you'd want it to be able to fly off of that. Weight savings, and a low draw plane. (Max amp draw being 3.3amps.)
Yes, 1.5 is an extremely low C rating. But if you want the plane to fly as long as possible, you'd want it to be able to fly off of that. Weight savings, and a low draw plane. (Max amp draw being 3.3amps.)
Foam Addict
Squirrel member
Hmm, this has the wheels turning. I'll bet that an uber light slowstick/blue baby type plane on an IPS could do very well on 2 amps on a 3 cell. I think the max thrust out of an IPS at 2ish amps was around 11 oz at a 25 mph pitch speed.
If you could get away with an 9 oz power system, (motor, batt, servos, RX, etc.) then a 4-5 oz airframe would still leave you with a .85-.79 thrust to weight ratio, and that's easily flyable.
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Murocflyer
Member
It wouldn't be a challenge for a sloper. You can easily fly for hours when the wind is blowing and for a light plane like the Weasel, you get tired/bored of flying before the battery goes out.
With a battery powered plane, a gearbox is necessary for the longest flight times.
Frank
With a battery powered plane, a gearbox is necessary for the longest flight times.
Frank
stay-fun
Helicopter addict
Really? Why? Don't we choose the correct kV rating and matching prop to get the highest efficiency? With a gearbox you're going to spin more parts, so I'd say eventually that'd be less efficient...
Murocflyer
Member
No, a geared setup will allow you to have a lot more efficiency over a direct drive motor. If you can get a custom wound direct drive motor with a KV around 490 or less than you may be able to match it with a DD, but using a 6.6:1 gear combo can decrease the amp draw which means you'll be flying a lot longer.
Frank
