

United States, VA, Arlington
Joined Dec 1996
12,788 Posts

Adam
Sounds like a really good idea if the model can take the weight of the drivetrain and decent nicads. It's close to a design I have been tinkering with for some time. Brushless are addictive and I fancy another small model that will really fly. Recall seeing Keith Shaw's well known BearKitty fly on an AF020G and 9 x 800AR, that was a little cracker. No hand launch sag, straight into a 30 deg climbout, and he flew for what I recall as around 8 minutes. If you can get that much power into the baby 3D, it should act like it looks. It's a little less span  Keith's model was around 36", as I recall  but low AR for plenty of wing. Getting 8 or 9 800AR, or equivalent if something new comes along, into the fuselage might be your biggest challenge. Regards Dereck 




Certainly no reason not to try. I would be leary about an overly large prop though. Not sure what would be needed on the gearing you have.
I think the reasoning behind the 010 is the size and weight of the motor/ESC system. I plan for a hacker B20 at 80100 watts in mine. This at a weight savings over the 020 and a bit heavier then the 010. Good luck and let us know how it goes! Steve 



I would use a 95 cam folding prop, and 8 500 mah batteries. i think it should work.



Kutztown, PA
Joined Feb 2001
372 Posts

I have been having a dialouge w/Sean Palmer at AeroModel and he has me interested in the B2015L w/4.1 gear box... looks like I may need to swing an 11x7 propellor for that set up though... here is what MotoCalc says about w/this setup on 8Cells:
Question: can we get 8 800AR's in the Fuse? =================== MotOpinion  Untitled 512ft above Sea Level, 70°F Motor: Hacker B20 15L; 3704rpm/V; 0.064 Ohms; 0.7A idle. Battery: Sanyo800AR; 8 cells; 800mAh @ 1.2V; 0.005 Ohms/cell. Speed Control: Generic Brushless ESC; 0.006 Ohms; High rate. Drive System: 11x7 Prop 4.1 gear PG; 11x7 (Pconst=1.25; Tconst=0.956) geared 4:1. Airframe: laser 3D; 277sq.in; 17.6oz; 9.1oz/sq.ft; Cd=0.039; Cl=0.17; Clopt=0.37; Clmax=0.89. Stats: 152 W/lb in; 117 W/lb out; 17mph stall; 26mph opt @ 58% (21:49); 38mph level @ 83% (10:47); 2551ft/min @ 90°; 348ft/min @ 8.7°. Power System Notes: The fullthrottle motor current at the best lifttodrag ratio airspeed (17.5A) falls between the motor's maximum efficiency current (8.5A) and its current at maximum output (51.7A), thus making effective use of the motor. Aerodynamic Notes: The static pitch speed (43mph) is within the range of approximately 2.5 to 3 times the model's stall speed (17mph), which is considered ideal for good performance. With a wing loading of 9.1oz/sq.ft, a model of this size will have very sedate flying characteristics. It will be suitable for relaxed flying, in calm or very light wind conditions. The static thrust (29.8oz) to weight (17.6oz) ratio is 1.7:1, which will result in extremely short takeoff runs, no difficulty taking off from grass surfaces (assuming sufficiently large wheels), and vertical climbouts. This model will probably be able to perform a hover or torque roll. At the best lifttodrag ratio airspeed, the excessthrust (17oz) to weight (17.6oz) ratio is 0.97:1, which will give very steep climbs and incredible acceleration. This model can easily do consecutive loops, and has sufficient inflight thrust for any aerobatic maneuver. General Notes: This analysis is based on calculations that take motor heating effects into account. =================================== Quote:
[This message has been edited by dmccoach (edited 06292001).] 




I don't think you can possibly get eight 800AR cells in there. The fuselage is really skinny. You'd have to let them hang halfway out under the belly hatch or butcher the fuselage beyond recognition. Also the landing gear on this model doesn't look like it will stand up to that much weight.




Mini Laser 3D with Astro 020
Im thinking of getting the Laser 3D and I have read the other thread in the plane. Someone said that with the 010 they had good performance. Well, im not looking for good performance, im looking for spectacular performance. with the 020 I should almost have unlimited vertical, and the torque to hover and torque roll. I dont think the 31 inch model is out of the 020's size range, because many speed 400 models are this size.
What do you think of my idea? and by the way the 020 is geared 3:1 



As Gerald said I doubt there is any easy way to get 8x800ARs in the fuselage as 8x500ARs are a pretty tight fit. You could move the servos behind the wing to make a little more room but you'd still have baance problems then.
One possible and somewhat wacky way might be to build them into the wing, as a flatpack one cell high and eight wide, but as the wingspar incorporates a spanwide shear web this would need some radical redsign of the spar across the centre section. Then you come to the undercarriage, which is pretty flimsy in the stock model and would need to be beefed up to carry the landing loads of the heavier model. 



Prop for 10x600AE and about 12 amps and you should get good performance on cells that fit.
Good luck! Steve 


Kutztown, PA
Joined Feb 2001
372 Posts

Guys, can you get 10 600 cells in it?
Also, what's the gear ratio on the AS 010? Her's a new MotoCalc approach w/8600AEcells: =========================================== MotOpinion  Laser3DHacker15L 512ft above Sea Level, 70°F Motor: Hacker B20 15L; 3704rpm/V; 0.064 Ohms; 0.7A idle. Battery: Sanyo 600AE; 8 cells; 600mAh @ 1.2V; 0.01 Ohms/cell. Speed Control: Generic Brushless ESC; 0.006 Ohms; High rate. Drive System: 10x6Prop 4.1 gear; 10x6 (Pconst=1.11; Tconst=0.956) geared 4.1:1. Airframe: Laser 3D; 277sq.in; 16.6oz; 8.6oz/sq.ft; Cd=0.039; Cl=0.17; Clopt=0.37; Clmax=0.89. Stats: 97 W/lb in; 82 W/lb out; 16mph stall; 25mph opt @ 71% (16:12); 37mph level @ 101% (8:55); 1262ft/min @ 34.5°; 338ft/min @ 8.7°. Power System Notes: The fullthrottle motor current at the best lifttodrag ratio airspeed (9.6A) falls between the motor's maximum efficiency current (9.2A) and its current at maximum output (61.4A), thus making effective use of the motor. Aerodynamic Notes: The static pitch speed (40mph) is within the range of approximately 2.5 to 3 times the model's stall speed (16mph), which is considered ideal for good performance. With a wing loading of 8.6oz/sq.ft, a model of this size will have very sedate flying characteristics. It will be suitable for relaxed flying, in calm or very light wind conditions. The static thrust (19.9oz) to weight (16.6oz) ratio is 1.2:1, which will result in extremely short takeoff runs, no difficulty taking off from grass surfaces (assuming sufficiently large wheels), and vertical climbouts. This model will probably be able to perform a hover or torque roll. At the best lifttodrag ratio airspeed, the excessthrust (9.3oz) to weight (16.6oz) ratio is 0.56:1, which will give steep climbs and excellent acceleration. This model should be able to do consecutive loops, and has sufficient inflight thrust for almost any aerobatic maneuver. General Notes: This analysis is based on calculations that take motor heating effects into account. ====================================== Quote:
[This message has been edited by dmccoach (edited 06302001).] 



Texas
Joined Aug 1999
5,110 Posts

Adam,
The wingspan is about the same as an s400 plane, but that does not mean this plane can handle it. I have a 48" wing on my Spider and it will not take a geared 020. There are more things to consider other than the wing size. The geared 020 is much heavier than the stock s280. In addition, the 020 needs a beefier 9 or 10 cell pack. That too will add extra weight. All that combined it going to raise the wing loading and that may offset any gains from the extra power since this plane was engineered as a lightweight flyer. Given that, the only way that you will ever know if it will work or is to give is a shot. Dave 


Kutztown, PA
Joined Feb 2001
372 Posts

Guys, MotoCalc suggests that the AS010 may be best for this airplane as Direct Drive (this is w/10 cells)... here are two outputs one direct and w/2.3 gear (and I don't know the AS 010 stock gear ratio):
========================================== MotOpinion  Laser3D AS 010 Direct 512ft above Sea Level, 70°F Motor: Astro Brushless 010 16T#25; 2000rpm/V; 0.4 Ohms; 0.15A idle. Battery: Sanyo 600AE; 10 cells; 600mAh @ 1.2V; 0.01 Ohms/cell. Speed Control: Generic Brushless ESC; 0.006 Ohms; High rate. Drive System: Direct Drive; 7x4 (Pconst=1.11; Tconst=0.956) direct drive. Airframe: Laser 3D; 277sq.in; 15.8oz; 8.2oz/sq.ft; Cd=0.039; Cl=0.17; Clopt=0.37; Clmax=0.89. Stats: 128 W/lb in; 71 W/lb out; 16mph stall; 25mph opt @ 55% (17:36); 36mph level @ 78% (8:26); 928ft/min @ 25.3°; 330ft/min @ 8.7°. Power System Notes: The fullthrottle motor current at the best lifttodrag ratio airspeed (11.2A) falls between the motor's maximum efficiency current (2A) and its current at maximum output (13.5A), thus making effective use of the motor. Aerodynamic Notes: The static pitch speed (46mph) is within the range of approximately 2.5 to 3 times the model's stall speed (16mph), which is considered ideal for good performance. With a wing loading of 8.2oz/sq.ft, a model of this size will have very sedate flying characteristics. It will be suitable for relaxed flying, in calm or very light wind conditions. The static thrust (12.6oz) to weight (15.8oz) ratio is 0.8:1, which will result in very short takeoff runs, no difficulty taking off from grass surfaces (assuming sufficiently large wheels), and steep climbouts. At the best lifttodrag ratio airspeed, the excessthrust (7.2oz) to weight (15.8oz) ratio is 0.45:1, which will give steep climbs and excellent acceleration. This model should be able to do consecutive loops, and has sufficient inflight thrust for almost any aerobatic maneuver. General Notes: This analysis is based on calculations that take motor heating effects into account. ========================================== MotOpinion  Laser3D AS010 2.3Gear 512ft above Sea Level, 70°F Motor: Astro Brushless 010 16T#25; 2000rpm/V; 0.4 Ohms; 0.15A idle. Battery: Sanyo 600AE; 10 cells; 600mAh @ 1.2V; 0.01 Ohms/cell. Speed Control: Generic Brushless ESC; 0.006 Ohms; High rate. Drive System: AS 010 2.3 Gear w/8x4; 8x4 (Pconst=1.11; Tconst=0.956) geared 2.3:1. Airframe: Laser 3D; 277sq.in; 15.8oz; 8.2oz/sq.ft; Cd=0.039; Cl=0.17; Clopt=0.37; Clmax=0.89. Stats: 51 W/lb in; 42 W/lb out; 16mph stall; 25mph opt @ 100% (20:59); 36mph level @ 101% (20:46); 3ft/min @ 0.1°; 330ft/min @ 8.7°. Possible Power System Problems: The fullthrottle motor current at the best lifttodrag ratio airspeed (1.6A) is lower than the motor's maximum efficiency current (2.1A). A higher current level would improve system efficiency. Current can be increased by using more cells, a larger diameter or higher pitched propeller, a lower gear ratio, or some combination of these methods. Possible Aerodynamic Problems: The static pitch speed (32mph) is less than 2.5 times the stall speed (16mph), which may result in reduced performance at typical flying speeds and a low maximum speed. This situation is usually acceptable for an electric sailplane or other slowflying model. Pitch speed can be increased by using a higher pitched and/or smaller diameter propeller, a lower gear ratio, a higher cell count, or some combination of these methods. Aerodynamic Notes: With a wing loading of 8.2oz/sq.ft, a model of this size will have very sedate flying characteristics. It will be suitable for relaxed flying, in calm or very light wind conditions. The static thrust (10oz) to weight (15.8oz) ratio is 0.63:1, which will result in short takeoff runs, and no difficulty taking off from grass surfaces (assuming sufficiently large wheels). At the best lifttodrag ratio airspeed, the excessthrust (0.6oz) to weight (15.8oz) ratio is 0.04:1, which will give very slow climbs and poor acceleration. Careful piloting will be required to maintain altitude. General Notes: This analysis is based on calculations that take motor heating effects into account. 


Kutztown, PA
Joined Feb 2001
372 Posts

Here is some 020 data (10 cells too)
MotOpinion  Laser3 AS 020 Geared 3.3 (per AS site) 512ft above Sea Level, 70°F Motor: Astro Brushless 020 7T#22 #802; 3085rpm/V; 0.145 Ohms; 0.7A idle. Battery: Sanyo 600AE; 10 cells; 600mAh @ 1.2V; 0.01 Ohms/cell. Speed Control: Generic Brushless ESC; 0.006 Ohms; High rate. Drive System: AS 020 3.3 Gear 8x5 Prop 3.3 gear; 8x5 (Pconst=1.11; Tconst=0.956) geared 3.3:1. Airframe: Laser 3D; 277sq.in; 18.1oz; 9.4oz/sq.ft; Cd=0.039; Cl=0.17; Clopt=0.37; Clmax=0.89. Stats: 75 W/lb in; 60 W/lb out; 17mph stall; 26mph opt @ 74% (15:43); 39mph level @ 101% (9:37); 722ft/min @ 18.1°; 353ft/min @ 8.7°. Possible Power System Problems: The fullthrottle motor current at the best lifttodrag ratio airspeed (6.7A) is lower than the motor's maximum efficiency current (6.9A). A higher current level would improve system efficiency. Current can be increased by using more cells, a larger diameter or higher pitched propeller, a lower gear ratio, or some combination of these methods. Aerodynamic Notes: The static pitch speed (44mph) is within the range of approximately 2.5 to 3 times the model's stall speed (17mph), which is considered ideal for good performance. With a wing loading of 9.4oz/sq.ft, a model of this size will have very sedate flying characteristics. It will be suitable for relaxed flying, in calm or very light wind conditions. The static thrust (13.2oz) to weight (18.1oz) ratio is 0.73:1, which will result in very short takeoff runs, no difficulty taking off from grass surfaces (assuming sufficiently large wheels), and steep climbouts. At the best lifttodrag ratio airspeed, the excessthrust (6.1oz) to weight (18.1oz) ratio is 0.34:1, which will give strong climbs and rapid acceleration. This model will most likely readily loop from level flight, and have sufficient inflight thrust for many aerobatic maneuvers. General Notes: This analysis is based on calculations that take motor heating effects into account. Quote:




Texas
Joined Aug 1999
5,110 Posts

I wonder about your analysis tools. Several owners of this plane report that it is an excellent flyer on it's stock configuration and that's only a ~s280/300.
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hanford,ca,usa
Joined Oct 2000
227 Posts

hey dan i should have the fuse framed by tomorow eve. got some loose cells i let you know what to fit, 11" prop hungh? well maybe we should go with a bit taller ld. gear and a bit heavier gauge!...john



Kutztown, PA
Joined Feb 2001
372 Posts

John, let's plan on 10" Prop potentially... still not sure what power system, but I am certain the stock gear box is unacceptable.
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