Goldberg Ultimate Power System

[Nightz]

Hello,

I'm trying to figure out a power system for the Goldberg Ultimate ARF. I'd like to try a Scorpion motor. I'd like to stick with a Castle ESC.

I ran some numbers through motocalc. It's really the first time I tried using motocalc to assist. I'm trying to hit 130-150 watts/lb. The airframe is about 6.12lb (97.8oz) without motor/batts/esc. Are motocalc flight times realistic? I'm looking for at least 7min flights.

Any suggestions?

Scorpion 4025-16 and A123 cells.

	Code:
	Static Analysis - Goldberg Ultimate ARF - Scorpion Sea Level, 29.92inHg, 59°F Motor: Scorpion 4025-16; 332rpm/V; 1.17A no-load; 0.034 Ohms. Battery: A123 ANR26650 M1 (30C); 6 to 8 series x 2 parallel cells; 2300mAh @ 3.3V; 0.016 Ohms/cell. Speed Control: Castle Creations Phoenix 80; 0.001 Ohms; High rate. Drive System: APC 16x10 Electric; 16x10 (Pconst=1.11; Tconst=1) direct drive. Airframe: Goldberg Ultimate; 980sq.in; 142.2 to 152.1oz RTF; 20.9 to 22.4oz/sq.ft; Cd=0.046; Cl=0; Clopt=0.37; Clmax=0.93. Cells Gear Diam Pitch Weight Batt Motor Motor Input InPLd Loss MGbOut OutPLd MotGb Shaft Prop Thrust PSpd RofC Time Ratio (in) (in) (oz) Amps Amps Volts (W) (W/lb) (W) (W) (W/lb) Ef(%) Ef(%) RPM (oz) (mph) (fpm) (m:s) 6S2P 1.00 16.0 10.0 142.2 31.1 31.1 18.3 567.9 63.9 57.6 510.2 57.4 89.8 82.9 5666 110.1 53.7 598 8:53 7S2P 1.00 16.0 10.0 147.2 39.1 39.1 20.9 816.1 88.7 87.0 729.1 79.3 89.3 80.7 6381 139.7 60.4 1263 7:04 8S2P 1.00 16.0 10.0 152.1 47.0 47.0 23.3 1096.4 115.3 129.4 967.0 101.7 88.2 78.0 7011 168.6 66.4 1915 5:53 Note: Motor performance calculations take ambient temperature and heating effects into account. Generated by MotoCalc 8.07, 2/21/2009 11:58 PM.

Using a Scorpion 4025-10 and A123 cells

	Code:
	Static Analysis - Goldberg Ultimate ARF - Scorpion v2 Sea Level, 29.92inHg, 59°F Motor: Scorpion 4025-10; 515rpm/V; 2.32A no-load; 0.016 Ohms. Battery: A123 ANR26650 M1 (30C); 6 to 8 series x 2 parallel cells; 2300mAh @ 3.3V; 0.016 Ohms/cell. Speed Control: Castle Creations Phoenix 80; 0.001 Ohms; High rate. Drive System: Generic 14x9in Prop; 14x9 (Pconst=1.31; Tconst=0.95) direct drive. Airframe: Goldberg Ultimate; 980sq.in; 142.2 to 152.1oz RTF; 20.9 to 22.4oz/sq.ft; Cd=0.046; Cl=0; Clopt=0.37; Clmax=0.93. Cells Gear Diam Pitch Weight Batt Motor Motor Input InPLd Loss MGbOut OutPLd MotGb Shaft Prop Thrust PSpd RofC Time Ratio (in) (in) (oz) Amps Amps Volts (W) (W/lb) (W) (W) (W/lb) Ef(%) Ef(%) RPM (oz) (mph) (fpm) (m:s) 6S2P 1.00 14.0 9.0 142.2 60.2 60.2 16.9 1014.0 114.1 113.2 900.8 101.3 88.8 75.6 8019 140.5 68.3 1696 4:35 7S2P 1.00 14.0 9.0 147.2 72.5 72.5 19.0 1375.7 149.5 171.2 1204.5 130.9 87.6 71.9 8835 170.5 75.3 2387 3:48 8S2P 1.00 14.0 9.0 152.1 82.9 82.9 21.0 1741.4 183.2 261.4 1480.0 155.7 85.0 67.6 9462 195.6 80.6 2998 3:20 Note: Motor performance calculations take ambient temperature and heating effects into account. Generated by MotoCalc 8.07, 2/22/2009 12:00 AM.

Thanks,
-Rocko

[mofosheee]

How did you come out on your CG Ultimate. I have the same sitting in the garage and am considering conversion

Thank you

Mofosheee

[Nightz]

	Quote: Originally Posted by mofosheee
	How did you come out on your CG Ultimate. I have the same sitting in the garage and am considering conversion Thank you Mofosheee

I went with a Scorpion 4025-12. CC HV 85. I'm going to try a few different props....15x8 and 15x10 I think. I'm going to try a 6S 5000 pack. It should be 3D capable.

I have not installed any electronics yet. I hope to get it in the air very very soon.

-Rocko

[mofosheee]

Knowing zip about electrics..........for giggles, look what I went thru in this wattflyer thread. The only way that I could get the 200 watts/lb. was to go to the 8S2P pack. More weight, but that's the nature of the beast.

Kyleservice tech sent me to school. Then things started to clic

Regards,

Mofo

[mofosheee]

Sorry:
http://www.wattflyer.com/forums/show...t=44686&page=3