1/2A 3D plane really 3D??
#5
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RE: 1/2A 3D plane really 3D??
I've built some stick and tissue PBFs that could hover with .049 - .061 power...but they weren't capable of any of the brute force 3D stuff like lolypops, pinwheels, repeating Lomcevaks, rising flat spins.
6 inches of prop disk is as far as you can go with instant throttle response. Electric planes in this size and weight range can turn more diameter and behave more like helicopters, putting less workload on the pilot.
The smallest 3D plane I ever saw that could REALLY do it all was the Morris Hobbies PENKNIFE with a piped MVVS .21
6 inches of prop disk is as far as you can go with instant throttle response. Electric planes in this size and weight range can turn more diameter and behave more like helicopters, putting less workload on the pilot.
The smallest 3D plane I ever saw that could REALLY do it all was the Morris Hobbies PENKNIFE with a piped MVVS .21
#6
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RE: 1/2A 3D plane really 3D??
ORIGINAL: nitroairplane
a speed 400 plane could have the same performance with a good .049 or a .061
a speed 400 plane could have the same performance with a good .049 or a .061
Yes and no. The electric can swing a much better prop than the glow versions do, so to go as fast or faster, you need to make a pantload more power. A Speed 400 is about a 75 watt to the prop motor on the old school 7 cell race setups. They were 80mph planes, and that's a real 80mph, not "looked like they were doing 110", and they primarily did it with a 4.75 x 4.75 prop. A T.D. 049 is also about a 75 watt engine but it can't be made to pull a 4.75x4.75 prop at any reasonable RPM, so you start putting smaller props on it to get the motor back into it's torque curve, but now you have a less efficient prop-prop efficiency falls off a cliff under 5".....
Now something like a HOT Norvel, VA, Cyclon etc. has 2 to 3 times the power of a Cox, but has to have props even smaller due to their radical timing numbers-but their power makes up some of the difference. Toad posts videos of his little screamers and does doppler runs, he breaks 110mph IIRC with a Cyclon and a toothpick prop. Real speed from there on out is going to come from bigger props with more pitch and getting milder timing. From my own testing, a Cyclon will spin a 4.7-4.7 at 27,500 even though it's not happy about it. Back when I got into the electric pylon game, that was what a good 150mph F5D would turn, and they weighed 3 times as much as a 1/2A would today.
There's a lot of speed to be had in 1/2A if that's an avenue a guy wants to pursue....
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RE: 1/2A 3D plane really 3D??
not to mention the shuriken .061 that was arguably the fastest 1/2a engine of all time.
if i where building a 3d 1/2a plane i would use a norvel big mig .061 converted to diesel with a 6 by 3 prop.
#8
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RE: 1/2A 3D plane really 3D??
Ok i have another question. i think i know the answer but want to see what comes up.
What is the best throttle-able .049-.09 out there? I can work a dud of an engine and get more power out of them. On my honker that is 18 ounces i can hover it at 3/4-7/8 power and can pull out slowly which is fine.
I am thinking of making a light weight plane and looking for engine options. i have the radio gear down to less than an ounce with enough power to fly a plane just need to find a good engine.
What is the best throttle-able .049-.09 out there? I can work a dud of an engine and get more power out of them. On my honker that is 18 ounces i can hover it at 3/4-7/8 power and can pull out slowly which is fine.
I am thinking of making a light weight plane and looking for engine options. i have the radio gear down to less than an ounce with enough power to fly a plane just need to find a good engine.
#9
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RE: 1/2A 3D plane really 3D??
Norvel big mig .061 or Norvel ame .061 the latter has harsher porting for smaller props only so i reccomend a diesel big mig .061
nut a throttled tee dee .049/.051 would also be ok but the norvel is better.
But my Reccomendation is a Norvel .074.
#10
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RE: 1/2A 3D plane really 3D??
I answered this yesterday, must have gone to never never land...Jeremey Chinn designed a plane called the Halfwit, try a search for it...it uses an arrow shaft for the main fuse, its a built up profile plane....Rog
http://www.rcuniverse.com/forum/Half...1332707/tm.htm
http://www.rcuniverse.com/forum/Half...1332707/tm.htm
#11
Senior Member
RE: 1/2A 3D plane really 3D??
ORIGINAL: nitroairplane
not to mention the shuriken .061 that was arguably the fastest 1/2a engine of all time.
not to mention the shuriken .061 that was arguably the fastest 1/2a engine of all time.
if i where building a 3d 1/2a plane i would use a norvel big mig .061 converted to diesel with a 6 by 3 prop.
#12
Senior Member
RE: 1/2A 3D plane really 3D??
ORIGINAL: airraptor
Ok i have another question. i think i know the answer but want to see what comes up.
What is the best throttle-able .049-.09 out there? I can work a dud of an engine and get more power out of them. On my honker that is 18 ounces i can hover it at 3/4-7/8 power and can pull out slowly which is fine.
I am thinking of making a light weight plane and looking for engine options. i have the radio gear down to less than an ounce with enough power to fly a plane just need to find a good engine.
Ok i have another question. i think i know the answer but want to see what comes up.
What is the best throttle-able .049-.09 out there? I can work a dud of an engine and get more power out of them. On my honker that is 18 ounces i can hover it at 3/4-7/8 power and can pull out slowly which is fine.
I am thinking of making a light weight plane and looking for engine options. i have the radio gear down to less than an ounce with enough power to fly a plane just need to find a good engine.
Norvel .074 (available now) or MP Jet .06 in either Diesel or Glow(Available, but expen$ive)
#14
RE: 1/2A 3D plane really 3D??
ORIGINAL: nitroairplane
Norvel big mig .061 or Norvel ame .061 the latter has harsher porting for smaller props only so i reccomend a diesel big mig .061
Norvel big mig .061 or Norvel ame .061 the latter has harsher porting for smaller props only so i reccomend a diesel big mig .061
nut a throttled tee dee .049/.051 would also be ok but the norvel is better.
But my Reccomendation is a Norvel .074.
#15
RE: 1/2A 3D plane really 3D??
I think the best 1/2a RC engines I ever used were some Cox .049 DragonFly style engines with the throttle sleeve. The engines had excellent throttle response. The low, mid and high throttles all worked really well. But at the time, the RC radio systems were still too heavy for 3D flying. But nowadays with our smaller more light servos and smaller receivers as well as smaller battery packs, we ought to be able to do quite well building up a 1/2a 3D plane that can perform reasonably well.
The problem you have with the 1/2a engine is primarily fuel draw. The 1/2a engines just can't draw fuel all that well, especially in a hover or doing strong aerobatic manuevers. So you need some sort of fuel tank pressure, but just some pressure, not too much though or the engine floods out at low throttle. So you are working with engines that have less power as you are running a muffler so you can get some muffler pressure out of it. You need the fuel tank to be as close as possible to the engine to minimize the poor fuel draw that you have with the engine.
So something like a Cox .049 Dragonfly with a good reed valve and a muffler/throttle sleeve that you can put a fitting on for muffler pressure ought to do the trick. But you need to build a lightweight plane. You still can't use the smallest servos as the 1/2a engine power pulses cause the airframe to vibrate and the control surfaces will stress the servos, so you still need to use maybe 9 gram servos on the elevator and ailerons, possibly the rudder too. But some 5 or 6 gram servos might work too. You'll need to watch the servos closely at first to ensure they aren't vibration sensitive. You might have to replace a few in some cases to get good ones. The small servos are made for electrics, so they don't worry much about the servos working with engines.
I have and have had some Norvel engines but they just do not work as well as the venerable Cox engines do. Although the Norvel .06 engine I had in a Lite-Machines Heli had a fairly decent whistle muffler throttle on it. But the others about the only thing the throttle was good for was to kill the engine when you got tired of flying.
Although I have a Cox .049Surestart with the new throttle body on it, I haven't tested it out to see how well it does. So that engine looks like a good candidate, but I haven't tried it yet.
With a 1/2a muffler on it, should get some nice muffler pressure to have it work OK for a small 3D plane.
The problem you have with the 1/2a engine is primarily fuel draw. The 1/2a engines just can't draw fuel all that well, especially in a hover or doing strong aerobatic manuevers. So you need some sort of fuel tank pressure, but just some pressure, not too much though or the engine floods out at low throttle. So you are working with engines that have less power as you are running a muffler so you can get some muffler pressure out of it. You need the fuel tank to be as close as possible to the engine to minimize the poor fuel draw that you have with the engine.
So something like a Cox .049 Dragonfly with a good reed valve and a muffler/throttle sleeve that you can put a fitting on for muffler pressure ought to do the trick. But you need to build a lightweight plane. You still can't use the smallest servos as the 1/2a engine power pulses cause the airframe to vibrate and the control surfaces will stress the servos, so you still need to use maybe 9 gram servos on the elevator and ailerons, possibly the rudder too. But some 5 or 6 gram servos might work too. You'll need to watch the servos closely at first to ensure they aren't vibration sensitive. You might have to replace a few in some cases to get good ones. The small servos are made for electrics, so they don't worry much about the servos working with engines.
I have and have had some Norvel engines but they just do not work as well as the venerable Cox engines do. Although the Norvel .06 engine I had in a Lite-Machines Heli had a fairly decent whistle muffler throttle on it. But the others about the only thing the throttle was good for was to kill the engine when you got tired of flying.
Although I have a Cox .049Surestart with the new throttle body on it, I haven't tested it out to see how well it does. So that engine looks like a good candidate, but I haven't tried it yet.
With a 1/2a muffler on it, should get some nice muffler pressure to have it work OK for a small 3D plane.
#16
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RE: 1/2A 3D plane really 3D??
How would a novel .061 run with a small belt drive to swing a bigger prop? Anyone done something like that. I have flown the Fliton small 3d planes and they are around 14-18 ounces ready to fly. They have a large cowl through and would need atleast a 7-8" prop to work well in a gas set up.
A 2-1 on the Norvel could spin a 7x4 around 13,000 i would think on a 2-1.
Any thoughts on this?
A 2-1 on the Norvel could spin a 7x4 around 13,000 i would think on a 2-1.
Any thoughts on this?
#17
RE: 1/2A 3D plane really 3D??
If you like a challenge then sure, why not, but a Norvel .074 can spin a 7x3 (at about 17000+rpm) and with very little extra weight compared to a .061.
#19
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RE: 1/2A 3D plane really 3D??
At risk of being Tarred AND Feathered...consider this:
A 24 Gram Hobby King 1300kv red and blue wonder turns an 8x4 at 12,000 rpms on 3S and 8 amps (@ 80% !! efficiency no less.
producing 22 ounces of thrust. This is an $8 ! motor .. add in a $10 esc a $6 battery and It's one light/potent/cheap power system Kids.
REAL 3D for as long as you want.. given a couple of spare batteries being on hand.
Just went and rechecked my spreadsheets Hows about 23+K rpms on a 4.7x4.7 Graupner Cam speed prop (better than the APC's) at 17 amps.
Same 24 gram 8$ motor but DIYrewound.
Can we say Better than many Glow 1/2 A s??
Erm... How??much does a 'turbo' plug cost??
Much as I love my 1/2 a's and diesels...I run them ever more rarely, usually for sentimental reasons only.
Although currently I do have a Lust on :-) for the latest issue Cyclon 049... even at it's $250 admission fee.
Figure If I just ignore it... it will dissipate
A 24 Gram Hobby King 1300kv red and blue wonder turns an 8x4 at 12,000 rpms on 3S and 8 amps (@ 80% !! efficiency no less.
producing 22 ounces of thrust. This is an $8 ! motor .. add in a $10 esc a $6 battery and It's one light/potent/cheap power system Kids.
REAL 3D for as long as you want.. given a couple of spare batteries being on hand.
Just went and rechecked my spreadsheets Hows about 23+K rpms on a 4.7x4.7 Graupner Cam speed prop (better than the APC's) at 17 amps.
Same 24 gram 8$ motor but DIYrewound.
Can we say Better than many Glow 1/2 A s??
Erm... How??much does a 'turbo' plug cost??
Much as I love my 1/2 a's and diesels...I run them ever more rarely, usually for sentimental reasons only.
Although currently I do have a Lust on :-) for the latest issue Cyclon 049... even at it's $250 admission fee.
Figure If I just ignore it... it will dissipate
#20
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RE: 1/2A 3D plane really 3D??
ORIGINAL: DeviousDave
Toad posts videos of his little screamers and does doppler runs, he breaks 110mph IIRC with a Cyclon and a toothpick prop. Real speed from there on out is going to come from bigger props with more pitch and getting milder timing. From my own testing, a Cyclon will spin a 4.7-4.7 at 27,500 even though it's not happy about it. Back when I got into the electric pylon game, that was what a good 150mph F5D would turn, and they weighed 3 times as much as a 1/2A would today.
There's a lot of speed to be had in 1/2A if that's an avenue a guy wants to pursue....
ORIGINAL: nitroairplane
a speed 400 plane could have the same performance with a good .049 or a .061
a speed 400 plane could have the same performance with a good .049 or a .061
There's a lot of speed to be had in 1/2A if that's an avenue a guy wants to pursue....
You would never be able to turn a Cyclon into a 3D engine.
The best choice like others have said is the Norvel .074...but that's cheating.
#21
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RE: 1/2A 3D plane really 3D??
Danilo yes i know all about the electric stuff. I just like to be different sometimes.
To the others i have found a couple of arf's that might do with the .074 here they are.
This one is 6.5 ounces as you see it.
http://www.hobbyking.com/hobbyking/s...76mm_ARF_.html
http://www.hobbyking.com/hobbyking/s...80mm_ARF_.html
http://www.hobbyking.com/hobbyking/s...40mm_ARF_.html
this might be to light in the fus area to hold up to glow but never know plus its ugly lol
http://www.hobbyking.com/hobbyking/s...00mm_ARF_.html
this is the same one but as a laser cut wood kit for 13.50 cents
http://www.hobbyking.com/hobbyking/s...00mm_KIT_.html
I really like the vision on the Norvel/NV .074 and a 6.3x4 prop......
To the others i have found a couple of arf's that might do with the .074 here they are.
This one is 6.5 ounces as you see it.
http://www.hobbyking.com/hobbyking/s...76mm_ARF_.html
http://www.hobbyking.com/hobbyking/s...80mm_ARF_.html
http://www.hobbyking.com/hobbyking/s...40mm_ARF_.html
this might be to light in the fus area to hold up to glow but never know plus its ugly lol
http://www.hobbyking.com/hobbyking/s...00mm_ARF_.html
this is the same one but as a laser cut wood kit for 13.50 cents
http://www.hobbyking.com/hobbyking/s...00mm_KIT_.html
I really like the vision on the Norvel/NV .074 and a 6.3x4 prop......
#22
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RE: 1/2A 3D plane really 3D??
Dickeybird [Milton Dickey] built a 1/2A 3D plane out of depron. IIRC, it weighed about 9 ozs RTF.
The 9 oz RTF 1/2A planes I've built for 3D don't really have the punch to do much more than some basic stuff.
I outfitted a .074 with a 8x3 prop and it performed pretty well....but now we're talking 3/4A.
The 9 oz RTF 1/2A planes I've built for 3D don't really have the punch to do much more than some basic stuff.
I outfitted a .074 with a 8x3 prop and it performed pretty well....but now we're talking 3/4A.
#23
Senior Member
RE: 1/2A 3D plane really 3D??
ORIGINAL: airraptor
How would a novel .061 run with a small belt drive to swing a bigger prop? Anyone done something like that. I have flown the Fliton small 3d planes and they are around 14-18 ounces ready to fly. They have a large cowl through and would need atleast a 7-8'' prop to work well in a gas set up.
A 2-1 on the Norvel could spin a 7x4 around 13,000 i would think on a 2-1.
Any thoughts on this?
How would a novel .061 run with a small belt drive to swing a bigger prop? Anyone done something like that. I have flown the Fliton small 3d planes and they are around 14-18 ounces ready to fly. They have a large cowl through and would need atleast a 7-8'' prop to work well in a gas set up.
A 2-1 on the Norvel could spin a 7x4 around 13,000 i would think on a 2-1.
Any thoughts on this?
It would certainly work but you'd have to account for losses in the gearbox. I have a TD .05 R/C on a 4:1 gearbox, I ran it once with a 14-6.... it sounded like the motor was really spinning up, definitely was not enough load... I'm guessing it was turning the prop in the 5500rpm range. I'd run this thing more but one of the gears has cracked and I haven't bothered to look for a replacement. A company called Silver Valley Innovations made it, pretty neat design.
#24
RE: 1/2A 3D plane really 3D??
airaptor, I think any one of those HobbyKing 3D planes would work as a 1/2a conversion. i bought the Mini-3D Gee Bee at the bottom of the list myself. I think I'll try it with a internal combustion engine myself too.
#25
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RE: 1/2A 3D plane really 3D??
How would a novel .061 run with a small belt drive to swing a bigger prop?