Dopesick

Okay here's the redone stats. Looks pretty well so far. And if I transfer over the motor, gearing, and go with a different prop size, THIS WILL WORK in the Formosa I will build next too!!!

MotOpinion - GWS - E-Starter Hacker B20 18L - 1080 Prop 2.8:1 GWS 350c "A" Gearing gearbox

25ft above Sea Level, 29.92inHg, 70°F

Motor: Hacker B20 18L; 3086rpm/V; 0.4A no-load; 0.092 Ohms.
Battery: Thunder Power TP2100; 2 cells; 2100mAh @ 3.7V; 0.022 Ohms/cell.
Speed Control: Castle Creations Phoenix 35; 0.0045 Ohms; High rate.
Drive System: Generic 9x6in Prop w/3:1 Gearbox; 10x8 (Pconst=1.25; Tconst=0.956) geared 2.8:1 (Eff=95%).
Airframe: GWS E-Starter; 265sq.in; 19.7oz; 10.7oz/sq.ft; Cd=0.055; Cl=0.47; Clopt=0.67; Clmax=1.24.
Stats: 80 W/lb in; 57 W/lb out; 15mph stall; 21mph opt @ 47% (73:50, 75°F); 25mph level @ 54% (55:25, 76°F); 1023ft/min @ 34.1°; -191ft/min @ -6°.

Power System Notes:

The full-throttle motor current at the best lift-to-drag ratio airspeed (14.8A) falls between the motor's maximum efficiency current (5.1A) and its current at theoretical maximum output (32.2A), thus making effective use of the motor.

Possible Aerodynamic Problems:

The diameter (10in) to pitch (8in) ratio is less than 1.5:1, which will result in reduced propeller efficiency at low speeds (the propeller is stalled). Although this is not likely to affect flying characteristics, it may make take-off or hand launching difficult.

Aerodynamic Notes:

The static pitch speed (43mph) is within the range of approximately 2.5 to 3 times the model's stall speed (15mph), which is considered ideal for good performance.
With a wing loading of 10.7oz/sq.ft, a model of this size will have trainer-like flying characteristics. It would make an ideal trainer, for use in calm to light wind conditions.
The static thrust (16.6oz) to weight (19.7oz) ratio is 0.84:1, which will result in very short take-off runs, no difficulty taking off from grass surfaces (assuming sufficiently large wheels), and steep climb-outs.
At the best lift-to-drag ratio airspeed, the excess-thrust (11oz) to weight (19.7oz) 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 in-flight thrust for almost any aerobatic maneuver.

General Notes:

This analysis is based on calculations that take motor heating effects into account.

In-flight Analysis - GWS - E-Starter Hacker B20 18L - 1080 Prop 2.8:1 GWS 350c "A" Gearing gearbox

25ft above Sea Level, 29.92inHg, 70°F

Motor: Hacker B20 18L; 3086rpm/V; 0.4A no-load; 0.092 Ohms.
Battery: Thunder Power TP2100; 2 cells; 2100mAh @ 3.7V; 0.022 Ohms/cell.
Speed Control: Castle Creations Phoenix 35; 0.0045 Ohms; High rate.
Drive System: Generic 9x6in Prop w/3:1 Gearbox; 10x8 (Pconst=1.25; Tconst=0.956) geared 2.8:1 (Eff=95%).
Airframe: GWS E-Starter; 265sq.in; 19.7oz; 10.7oz/sq.ft; Cd=0.055; Cl=0.47; Clopt=0.67; Clmax=1.24.
Stats: 80 W/lb in; 57 W/lb out; 15mph stall; 21mph opt @ 47% (73:50, 75°F); 25mph level @ 54% (55:25, 76°F); 1023ft/min @ 34.1°; -191ft/min @ -6°.

AirSpd Drag Lift Batt Motor Motor Input Loss MGbOut MotGb Shaft Motor Prop Thrust PSpd Prop Total Time
(mph) (oz) (oz) Amps Amps Volts (W) (W) (W) Ef(%) Ef(%) RPM RPM (oz) (mph) Ef(%) Ef(%) (m:s)

0.0 0.0 0.0 14.6 14.6 6.7 98.0 27.9 70.0 71.5 64.6 15971 5704 16.6 43.2 0.0 0.0 8:36
1.0 0.0 0.0 14.6 14.6 6.7 98.0 27.9 70.0 71.5 64.6 15971 5704 16.4 42.2 2.9 1.9 8:36
2.0 0.0 0.1 14.6 14.6 6.7 98.0 27.9 70.1 71.5 64.6 15969 5703 16.2 41.2 5.7 3.7 8:36
3.0 0.0 0.3 14.7 14.7 6.7 98.1 28.0 70.1 71.5 64.6 15962 5701 16.0 40.2 8.5 5.5 8:36
4.0 0.1 0.5 14.7 14.7 6.7 98.2 28.0 70.1 71.4 64.6 15953 5698 15.8 39.2 11.2 7.2 8:35
5.0 0.1 0.8 14.7 14.7 6.7 98.3 28.1 70.2 71.4 64.5 15943 5694 15.7 38.1 13.8 8.9 8:34
6.0 0.1 1.1 14.7 14.7 6.7 98.4 28.2 70.2 71.4 64.5 15931 5689 15.5 37.1 16.4 10.6 8:34
7.0 0.2 1.6 14.7 14.7 6.7 98.6 28.3 70.3 71.3 64.4 15918 5685 15.3 36.1 18.9 12.2 8:33
8.0 0.2 2.0 14.8 14.8 6.7 98.7 28.4 70.4 71.3 64.4 15904 5680 15.1 35.0 21.4 13.7 8:32
9.0 0.3 2.6 14.8 14.8 6.7 98.9 28.5 70.4 71.2 64.3 15890 5675 15.0 34.0 23.7 15.3 8:31
10.0 0.4 3.2 14.8 14.8 6.7 99.0 28.5 70.5 71.2 64.3 15877 5670 14.8 33.0 26.0 16.7 8:30
11.0 0.5 3.9 14.8 14.8 6.7 99.2 28.6 70.5 71.1 64.2 15863 5665 14.6 31.9 28.3 18.2 8:29
12.0 0.5 4.6 14.9 14.9 6.7 99.3 28.7 70.6 71.1 64.2 15851 5661 14.5 30.9 30.5 19.6 8:28
13.0 0.6 5.4 14.9 14.9 6.7 99.4 28.8 70.6 71.1 64.1 15840 5657 14.3 29.9 32.6 20.9 8:28
14.0 0.7 6.3 14.9 14.9 6.7 99.5 28.8 70.7 71.0 64.1 15831 5654 14.1 28.8 34.6 22.2 8:27
15.0 0.9 7.2 14.9 14.9 6.7 99.6 28.9 70.7 71.0 64.1 15824 5651 13.9 27.8 36.6 23.4 8:27
16.0 1.0 8.2 14.9 14.9 6.7 99.7 28.9 70.7 71.0 64.0 15819 5650 13.7 26.8 38.5 24.6 8:26
17.0 1.1 9.2 14.9 14.9 6.7 99.7 28.9 70.8 71.0 64.0 15817 5649 13.5 25.8 40.3 25.8 8:26
18.0 1.2 10.3 14.9 14.9 6.7 99.6 28.9 70.7 71.0 64.0 15820 5650 13.3 24.8 42.1 26.9 8:27
19.0 1.4 11.5 14.9 14.9 6.7 99.5 28.8 70.7 71.0 64.1 15829 5653 13.1 23.8 43.7 28.0 8:27
20.0 1.5 12.8 14.9 14.9 6.7 99.4 28.7 70.6 71.1 64.1 15845 5659 12.9 22.9 45.3 29.1 8:28
21.0 1.7 14.1 14.8 14.8 6.7 99.1 28.6 70.5 71.1 64.2 15868 5667 12.7 21.9 46.8 30.1 8:30
22.0 1.8 15.5 14.8 14.8 6.7 98.8 28.4 70.4 71.2 64.3 15897 5678 12.4 21.0 48.2 31.0 8:32
23.0 2.0 16.9 14.7 14.7 6.7 98.4 28.2 70.2 71.4 64.5 15933 5690 12.2 20.1 49.5 31.9 8:34
24.0 2.2 18.4 14.6 14.6 6.7 98.0 27.9 70.0 71.5 64.6 15970 5704 12.0 19.2 50.8 32.8 8:36
25.0 2.4 20.0 14.6 14.6 6.7 97.5 27.7 69.8 71.6 64.8 16015 5720 11.7 18.3 52.0 33.7 8:39
26.0 2.6 21.6 14.5 14.5 6.7 96.9 27.3 69.5 71.8 65.0 16068 5739 11.4 17.5 53.1 34.5 8:43
27.0 2.8 23.3 14.3 14.3 6.7 96.2 26.9 69.2 72.0 65.2 16128 5760 11.2 16.6 54.1 35.3 8:47
28.0 3.0 25.0 14.2 14.2 6.7 95.5 26.5 68.9 72.2 65.5 16192 5783 10.9 15.8 55.1 36.0 8:51
29.0 3.2 26.9 14.1 14.1 6.7 94.7 26.1 68.6 72.4 65.7 16262 5808 10.7 15.0 56.0 36.8 8:56
30.0 3.4 28.7 14.0 14.0 6.7 93.8 25.7 68.2 72.7 66.0 16336 5834 10.4 14.2 56.8 37.5 9:02
31.0 3.6 30.7 13.8 13.8 6.7 92.9 25.2 67.7 72.9 66.3 16416 5863 10.1 13.4 57.5 38.2 9:08
32.0 3.9 32.7 13.6 13.6 6.7 91.9 24.7 67.2 73.2 66.6 16501 5893 9.9 12.6 58.2 38.8 9:14
33.0 4.1 34.8 13.5 13.5 6.7 90.9 24.1 66.7 73.4 67.0 16591 5925 9.6 11.9 58.9 39.4 9:21
34.0 4.4 36.9 13.3 13.3 6.8 89.7 23.5 66.2 73.7 67.3 16688 5960 9.3 11.2 59.4 40.0 9:29
35.0 4.6 39.1 13.1 13.1 6.8 88.5 22.9 65.5 74.1 67.7 16793 5998 9.1 10.4 60.0 40.6 9:38
36.0 4.9 41.4 12.9 12.9 6.8 87.1 22.3 64.8 74.4 68.1 16906 6038 8.8 9.7 60.4 41.2 9:48
37.0 5.2 43.7 12.6 12.6 6.8 85.6 21.6 64.0 74.8 68.6 17026 6081 8.5 9.1 60.9 41.7 9:59
38.0 5.5 46.1 12.4 12.4 6.8 84.1 20.9 63.2 75.1 69.0 17153 6126 8.2 8.4 61.2 42.3 10:11
39.0 5.8 48.6 12.1 12.1 6.8 82.5 20.2 62.3 75.5 69.5 17286 6174 7.9 7.8 61.6 42.8 10:25
40.0 6.1 51.1 11.8 11.8 6.8 80.7 19.4 61.3 75.9 70.0 17425 6223 7.6 7.1 61.9 43.3 10:39
41.0 6.4 53.7 11.5 11.5 6.8 78.9 18.7 60.2 76.3 70.6 17570 6275 7.4 6.5 62.1 43.8 10:56
42.0 6.7 56.3 11.2 11.2 6.9 77.0 17.9 59.1 76.7 71.1 17720 6329 7.1 5.9 62.3 44.3 11:13

Note: Motor performance calculations take ambient temperature and heating effects into account.

Generated by MotoCalc 7.08, 3/4/2004 8:18 PM.