Indoor 3D , Texas Style
12-11-2002 | 05:53 AM
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From: Savannah ,
GA
Indoor 3D , Texas Style
Hi Guys,
I know that this may be more suited for the electric or profile airplane categories but I thought many of you 3D/precision fliers might appreciate the video found through the following link...
http://www.team-rebel.org/GRH_E3D_001_0004.wmv
It's a fairly large file so a fast connection is preferred.
My friend Bill Higgins did an amazing job on the video compilation and I truly think you'll enjoy it.
The airplane is called the Tribute 3D V1.7 and it is designed specifically for the Hacker B20 line of brushless motors. Currently I'm using the Hacker B20 26S with a 4:1 gear reduction, APC 11x4.7 prop and the new PowerfLite Lithium-Polymer batteries. This combination allows 3+ minutes of hovering (T/W >=1) along with 10+ minutes of normal flying. The wingspan is roughly 40" and the empty weight is 10-11 oz.
This is the 7th iteration of the Tribute design and great care was taken to insure that the airplane's performance and handling qualities were up to the standards expected from a seasoned 3D/precision aerobatic pilot.
The airplane was designed to be a 3D trainer for one to learn the basics of 3D flying without the fear of crashing a more expensive model. The thrustline and roll damping were setup to provide a very neutral/damped feel in pitch and yaw while also having enough roll damping to keep the torque roll spinning at a docile rate thus allowing the new 3D pilot more time to think before being forced to make corrections.
We actually went so far as to predict the aerodynamic roll damping as a function of the wing planform shape and balance this damping moment with the motor torque such that the steady state spin rate would be less than or equal to 180 degrees per second. This extra damping allows you to lean the airplane off vertical only a few degrees and prevent the torque roll from ever happening.
It's also capable of fairly steady elevators/harriers and high-aoa rolling circles. The airplane is quite crash resistant and we've yet to destroy an airplane completely. Typical crash damage is quickly repaired with Scotch tape or a new prop. Only once did we render the airplane unflyable when we were flying out a gym door in knife edge and accidentally hit the door frame.
I currently have no plans to kit the airplane because of the hassle, but I expect to see a major hobby distributor bring it, or a variant, to market in the near future.
Respectfully,
George Hicks
Team JR
I know that this may be more suited for the electric or profile airplane categories but I thought many of you 3D/precision fliers might appreciate the video found through the following link...
http://www.team-rebel.org/GRH_E3D_001_0004.wmv
It's a fairly large file so a fast connection is preferred.
My friend Bill Higgins did an amazing job on the video compilation and I truly think you'll enjoy it.
The airplane is called the Tribute 3D V1.7 and it is designed specifically for the Hacker B20 line of brushless motors. Currently I'm using the Hacker B20 26S with a 4:1 gear reduction, APC 11x4.7 prop and the new PowerfLite Lithium-Polymer batteries. This combination allows 3+ minutes of hovering (T/W >=1) along with 10+ minutes of normal flying. The wingspan is roughly 40" and the empty weight is 10-11 oz.
This is the 7th iteration of the Tribute design and great care was taken to insure that the airplane's performance and handling qualities were up to the standards expected from a seasoned 3D/precision aerobatic pilot.
The airplane was designed to be a 3D trainer for one to learn the basics of 3D flying without the fear of crashing a more expensive model. The thrustline and roll damping were setup to provide a very neutral/damped feel in pitch and yaw while also having enough roll damping to keep the torque roll spinning at a docile rate thus allowing the new 3D pilot more time to think before being forced to make corrections.
We actually went so far as to predict the aerodynamic roll damping as a function of the wing planform shape and balance this damping moment with the motor torque such that the steady state spin rate would be less than or equal to 180 degrees per second. This extra damping allows you to lean the airplane off vertical only a few degrees and prevent the torque roll from ever happening.
It's also capable of fairly steady elevators/harriers and high-aoa rolling circles. The airplane is quite crash resistant and we've yet to destroy an airplane completely. Typical crash damage is quickly repaired with Scotch tape or a new prop. Only once did we render the airplane unflyable when we were flying out a gym door in knife edge and accidentally hit the door frame.
I currently have no plans to kit the airplane because of the hassle, but I expect to see a major hobby distributor bring it, or a variant, to market in the near future.
Respectfully,
George Hicks
Team JR
12-11-2002 | 06:39 AM
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From: Franklin,
TN
Indoor 3D , Texas Style
lightened photo
Man, what an awesome video! Loved the rolling circle! So, from your post, is this the only plane in existence, then? Not available in any form yet?
Kudos to the designer and pilot!!!
-s
Man, what an awesome video! Loved the rolling circle! So, from your post, is this the only plane in existence, then? Not available in any form yet?
Kudos to the designer and pilot!!!
-s
12-12-2002 | 04:12 AM
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From: The Woodlands,
TX
3D
I want one. I have the motor.
I pay cash.
Willing to meet you someplace between Houston and S.A.
email me privately.
[email protected]
I pay cash.
Willing to meet you someplace between Houston and S.A.
email me privately.
[email protected]
12-12-2002 | 04:03 PM
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From: Whitehall, PA
3D !!
Hey George, that is way cool !! Got to get one or more when they come out. Plz try to let us know who is going to kit em.Can you tell me the best place to get the Hacker and other equip.
I just ordered similar size SU-31 from Extreme Team http://www.extremeteam.info/ in Sweeden, looks cool too and is using the same motor. Have you seen or tried the Hecell Nicads yet, sound real impressive ! ? Keep up the GREAT work , this will be a huge seller for sure ! Merry Christmas and Happy New Year !! Rod & Chris
12-12-2002 | 07:59 PM
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From: Savannah ,
GA
Indoor 3D , Texas Style
Rod & Chris,
Glad you like the airplane.
As soon as the release information is finalized I'll let you guys know. Because of my dealings with this company no plans will be available until release.
If you're going to buy a Hacker motor the best place to get quality service, support and information is through Aero-Model in Tempe AZ. Aero-Model is the official US distributor. Sean Plummer and Tim Lime have been a tremendous help in finding the correct power plant for this airplane.
Aero-Model (480) 726-7519
http://www.aero-model.com
I have yet to try the new HeCell NiMH but they do look promising. The fact that you can pull more current with the Nimh than the Li-poly can be an advantage, but the Li-poly energy density is still higher thus making it theoretically a superior power source, provided you combine it with a motor that produces the torque per amp that you need while also staying within the batteries current limits. We tried 3-4 different motor winds until we found one that really worked well.
I have a feeling that Torpis' Sukhoi (which is really awesome BTW!) with a B-20 26S and a 6-cell Li-poly pack, could come out in the 15-16oz flying weight while providing 3+ minutes of hover and 10+ minutes of normal flying. Perhaps they are getting this now but their extreme test video only shows the hover duration’s to be 65 seconds.
The motors they are using are "hot wind" motors (B20-12L, 15L) and they require more current. The obvious advantages are that you can fast charge the NiMH, they are cheaper than the Li-poly, and you don't have to have a specialized charger. The HeCell in my opinion the best NiMH available for what we're trying to do.
I hope this helps,
George Hicks
Glad you like the airplane.
As soon as the release information is finalized I'll let you guys know. Because of my dealings with this company no plans will be available until release. If you're going to buy a Hacker motor the best place to get quality service, support and information is through Aero-Model in Tempe AZ. Aero-Model is the official US distributor. Sean Plummer and Tim Lime have been a tremendous help in finding the correct power plant for this airplane.
Aero-Model (480) 726-7519
http://www.aero-model.com
I have yet to try the new HeCell NiMH but they do look promising. The fact that you can pull more current with the Nimh than the Li-poly can be an advantage, but the Li-poly energy density is still higher thus making it theoretically a superior power source, provided you combine it with a motor that produces the torque per amp that you need while also staying within the batteries current limits. We tried 3-4 different motor winds until we found one that really worked well.
I have a feeling that Torpis' Sukhoi (which is really awesome BTW!) with a B-20 26S and a 6-cell Li-poly pack, could come out in the 15-16oz flying weight while providing 3+ minutes of hover and 10+ minutes of normal flying. Perhaps they are getting this now but their extreme test video only shows the hover duration’s to be 65 seconds.
The motors they are using are "hot wind" motors (B20-12L, 15L) and they require more current. The obvious advantages are that you can fast charge the NiMH, they are cheaper than the Li-poly, and you don't have to have a specialized charger. The HeCell in my opinion the best NiMH available for what we're trying to do.
I hope this helps,
George Hicks
12-13-2002 | 06:09 AM
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From: Whitehall, PA
Hacker motor
Hi George, thanks so much for the reply and all the great info !
Man , those B20 Hackers are kinda pricy !! But I understand one can not skimp much here or we will not get the awesome performance you guys are getting. Chris and I only dabble in the elec world , so we have a lot to learn for sure ! This stuff has come a lomg way in a short time and we are so impressed with what you and some others are doing, Hats OFF to ya - way COOL !!!! We do fly some indoor and park flyers but mostly into FF , IMAC and 3D , so this new 3D elec stuff has really gotten our int for sure. I'm sure we will have some more Q's for ya soon and please do let us know when they kit your plane kitted, we will order at least 2 for sure ! Thanks again George , you have been very helpful. Congradulations on what looks like a great design, hope you sell many of em. Happy Holidays ! Rod & Chris
Man , those B20 Hackers are kinda pricy !! But I understand one can not skimp much here or we will not get the awesome performance you guys are getting. Chris and I only dabble in the elec world , so we have a lot to learn for sure ! This stuff has come a lomg way in a short time and we are so impressed with what you and some others are doing, Hats OFF to ya - way COOL !!!! We do fly some indoor and park flyers but mostly into FF , IMAC and 3D , so this new 3D elec stuff has really gotten our int for sure. I'm sure we will have some more Q's for ya soon and please do let us know when they kit your plane kitted, we will order at least 2 for sure ! Thanks again George , you have been very helpful. Congradulations on what looks like a great design, hope you sell many of em. Happy Holidays ! Rod & Chris
12-14-2002 | 04:58 AM
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From: Savannah ,
GA
Indoor 3D , Texas Style
The airfoil is a 1.75% thick flat plate...the funny and perhaps surprising thing is I wouldn't want it any other way.
When you start looking for airfoil sections for aerobatic aircraft the obvious choice is something of a symmetrical nature simply because you don't bias its force producing capability in a certain direction. When you couple this with low Reynolds number aerodynamics you quickly come to the conclusion that a thin section will be the best from a handling qualities point of view simply because the nondimensional aerodynamic coefficients aren't strong functions of airspeed. (Assuming of course that the size of the airplane is fixed and the kinematic viscosity of air isn't apt to change wildly in the near future).
In other words the airplane's aerodynamics should vary in a linear fashion no matter what speed you're flying.
A good example of this sort of thing is the small balsa hand-launch gliders you can buy at any convenience store. Notice that they have a simple flat (or curved) plate for an airfoil section. Most think that this is done simply because it's cheaper and easier to manufacture but lets suppose that they outfitted their little glider with a standard NACA 4412. If you look at the 2D wind tunnel data you see that the lift curve, drag polar, and pitching moment coefficients vary wildly until you get to a Reynolds (Re) number of greater than 250,000. Actually it only starts to really look good above 3,000,000 which happens to be the Reynolds numbers that it was designed to operate in. If we measure the airspeeds that our little Wal-Mart glider flies at we calculate that it operates from a Re of 10,000-80,000. This assumes that you can throw it at 60mph and it’s trimmed to glide at a min-sink speed of roughly 10 ft/s. Notice that the 12% thick NACA 4412 would be a total disaster in this Re range since the aerodynamics vary so much. Conversely, if you look at the data for flat or curved thin plates you see that the lift curves, polars and pitching moment plots barely change from a Re of 20,000 to 250,000 making it a great choice. In comparison the Tribute operates from roughly 32,000 to 300,000 which also makes it my airfoil section of choice.
The funny thing about aerobatics, especially precision and 3D model aerobatics, is that our pilot opinion, of the airplane’s handling qualities, is governed almost completely by the linearity of the aerodynamics. When we command a certain amount of Tx stick travel we expect a proportional amount of response from the airplane. If this response occurs in a nearly linear manner (or we can setup the curve via exponential or some other mechanism to make it feel linear) the human controller can easily command the model and will often pronounce the handling as good or even exceptional depending on his background and ability.
Simply put “be wise…linearize”
Hope this clears up some of the confusion in the airfoil selection,
George Hicks
Team JR
PS To answer another gentleman’s question, the model is constructed from blue insulation foam.
When you start looking for airfoil sections for aerobatic aircraft the obvious choice is something of a symmetrical nature simply because you don't bias its force producing capability in a certain direction. When you couple this with low Reynolds number aerodynamics you quickly come to the conclusion that a thin section will be the best from a handling qualities point of view simply because the nondimensional aerodynamic coefficients aren't strong functions of airspeed. (Assuming of course that the size of the airplane is fixed and the kinematic viscosity of air isn't apt to change wildly in the near future).
In other words the airplane's aerodynamics should vary in a linear fashion no matter what speed you're flying.
A good example of this sort of thing is the small balsa hand-launch gliders you can buy at any convenience store. Notice that they have a simple flat (or curved) plate for an airfoil section. Most think that this is done simply because it's cheaper and easier to manufacture but lets suppose that they outfitted their little glider with a standard NACA 4412. If you look at the 2D wind tunnel data you see that the lift curve, drag polar, and pitching moment coefficients vary wildly until you get to a Reynolds (Re) number of greater than 250,000. Actually it only starts to really look good above 3,000,000 which happens to be the Reynolds numbers that it was designed to operate in. If we measure the airspeeds that our little Wal-Mart glider flies at we calculate that it operates from a Re of 10,000-80,000. This assumes that you can throw it at 60mph and it’s trimmed to glide at a min-sink speed of roughly 10 ft/s. Notice that the 12% thick NACA 4412 would be a total disaster in this Re range since the aerodynamics vary so much. Conversely, if you look at the data for flat or curved thin plates you see that the lift curves, polars and pitching moment plots barely change from a Re of 20,000 to 250,000 making it a great choice. In comparison the Tribute operates from roughly 32,000 to 300,000 which also makes it my airfoil section of choice.
The funny thing about aerobatics, especially precision and 3D model aerobatics, is that our pilot opinion, of the airplane’s handling qualities, is governed almost completely by the linearity of the aerodynamics. When we command a certain amount of Tx stick travel we expect a proportional amount of response from the airplane. If this response occurs in a nearly linear manner (or we can setup the curve via exponential or some other mechanism to make it feel linear) the human controller can easily command the model and will often pronounce the handling as good or even exceptional depending on his background and ability.
Simply put “be wise…linearize”
Hope this clears up some of the confusion in the airfoil selection,
George Hicks
Team JR
PS To answer another gentleman’s question, the model is constructed from blue insulation foam.
12-14-2002 | 05:45 AM
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From: Savannah ,
GA
Indoor 3D , Texas Style
Sorry Randy,
I went a little overboard there...I get that question a lot and took this as an opportunity to answer it once and for all.
Thanks for hanging in there Hope it wasn't too boring.
George
I went a little overboard there...I get that question a lot and took this as an opportunity to answer it once and for all.
Thanks for hanging in there
Hope it wasn't too boring.George
12-14-2002 | 06:51 AM
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From: Mary Esther, Florida, FL
Indoor 3D , Texas Style
George:
Like the airplane, like the picture part of the demo video.
But I would much rather hear the motor, the prop, and any background comments than somebody who sounds like he's dying with a big Bowie knife stuck deeply into his belly.
Twin engines moan, or the rudder input makes you groan.
Bill.
Like the airplane, like the picture part of the demo video.
But I would much rather hear the motor, the prop, and any background comments than somebody who sounds like he's dying with a big Bowie knife stuck deeply into his belly.
Twin engines moan, or the rudder input makes you groan.
Bill.
12-14-2002 | 12:42 PM
#18
Indoor 3D , Texas Style
George,
Seriously... I really appreciate your taking the time to provide such a comprehensive answer. I'm simply incapable of comprehending it. Not boring at all I had no clue there was this much technical research behind your really cool design.
Seriously... I really appreciate your taking the time to provide such a comprehensive answer. I'm simply incapable of comprehending it. Not boring at all
I had no clue there was this much technical research behind your really cool design.
12-14-2002 | 01:47 PM
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From: Winter Garden,
FL
Pictures
Hey George,
First of all, I think the video is GREAT with the music ! I guess you cant please everybody.
Is there a way you could post some close up pix of the Tribute?
And has PowerFlite released the battery you are using?
I too would like to be on the list for when these planes are released by whomever???
Thanks,
Curt
First of all, I think the video is GREAT with the music ! I guess you cant please everybody.
Is there a way you could post some close up pix of the Tribute?
And has PowerFlite released the battery you are using?
I too would like to be on the list for when these planes are released by whomever???
Thanks,
Curt
12-16-2002 | 12:04 PM
#22
Indoor 3D , Texas Style
Hi
cool plane! just DLing the video
how much power does the B20S output?
My B20L is pushed to the limit in the su31, if useing 8cells and 12x6prop, temp 96C after flying
going to try a 18L on 5x2040mah, ~185watts @5C, should work
think the voltage drops some, but they should hold up I think.
cool plane! just DLing the video
how much power does the B20S output?
My B20L is pushed to the limit in the su31, if useing 8cells and 12x6prop, temp 96C after flying
going to try a 18L on 5x2040mah, ~185watts @5C, should work
think the voltage drops some, but they should hold up I think.
12-16-2002 | 11:06 PM
#24
Indoor 3D , Texas Style
Hi
It´s up and running again... We exeeded the 15Gb/month BW limit...
I´ll try to recuce the size of the videos, and upload them again after the change of month.
It´s up and running again... We exeeded the 15Gb/month BW limit...
I´ll try to recuce the size of the videos, and upload them again after the change of month.
12-17-2002 | 06:14 AM
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From: Toledo,
OH
Indoor 3D , Texas Style
Well that was probably the best RC video I've seen posted on RCU, or anywhere else for that matter. Truely awesome job! High quality, well correographed, great music & awesome flying! Get enough guys to watch this video and you'll have the next Zagi on your hands! Can I ask a aquestion? I'm purely a hobbiest when it comes to aerodynamics, but how do you calculate the torque roll rate / what factors impact it?
