| |  RC Tips/Hints!
| 2-Stroke Engine Prop Sizes |
Engine Size
(cu.in) | Starting Size | Other Sizes To Try |
|---|
| .049 | 6-3 | 5.25-4, 5.5-4, 6-3.5, 6-4, 7-3 |
| .09 | 7-4 | 7-3, 7-4.5, 7-5 |
| .15 | 8-4 | 8-5, 8-6, 9-4 |
| .19 -.25 | 9-4 | 8-5, 8-6, 9-4 |
| .29 -.30 | 9-6 | 9-7, 9.5-6, 10-6 |
| .35 -.36 | 10-6 | 9-7, 10-5, 11-4 |
| .40 | 10-6 | 9-8, 11-5 |
| .45 | 10-7 | 10-6, 11-5, 11-6, 12-4 |
| .50 | 11-6 | 10-8, 11-7, 12-4, 12-5 |
| .60 -.61 | 11-7 | 11-7.5, 11-7.75, 11-8, 12-6 |
| .70 | 12-6 | 11-8, 12-8, 13-6, 14-4 |
| .78 -.80 | 13-6 | 12-8, 14-4, 14-5 |
| .90 -.91 | 14-6 | 13-8, 15-6, 16-5 |
| 1.08 | 16-6 | 15-8, 18-5 |
| 1.2 | 16-8 | 16-10, 18-5, 18-6 |
| 1.5 | 18-6 | 18-8, 20-6 |
| 1.8 | 18-8 | 18-10, 20-6, 20-8, 22-6 |
| 2.0 | 20-8 | 18-10, 20-6, 20-10, 22-6 |
 Top |
| 4-Stroke Engine Prop Sizes |
Engine Size
(cu.in) | Starting Size | Other Sizes To Try |
|---|
| .20 -.21 | 9-6 | 9-5, 10-5 |
| .40 | 11-6 | 10-6, 10-7, 11-4, 11-5,
11-7, 11-7.5, 12-4, 12-5 |
| .45 -.48 | 11-6 | 10-6, 10-7, 10-8, 11-7,
11-7.5, 12-4, 12-5, 12-6 |
| .60 -.65 | 12-6 | 11-7.5, 11-7.75, 11-8, 12-8,
13-5, 13-6, 14-5, 14-6 |
| .80 | 13-6 | 12-8, 13-8, 14-4, 14-6 |
| .90 | 14-6 | 13-6, 14-8, 15-6, 16-6 |
| 1.20 | 16-6 | 14-8, 15-6, 15-8, 16-8,
17-6, 18-5,18-6 |
| 1.60 | 18-6 | 15-6, 15-8, 16-8,
18-6, 18-8, 20-6 |
| 2.40 | 18-10 | 18-12, 20-8, 20-10 |
| 2.70 | 20-8 | 18-10, 18-12, 20-10 |
| 3.00 | 20-10 | 18-12, 20-10 |
| Top |
| Engine Size Conversion Chart (ci=cc) |
|---|
| Cubic Inches | Cubic Centimeters |
|---|
| .049 | .8 |
| .09 | 1.5 |
| .15 | 2.5 |
| .19 | 3.1 |
| .21 | 3.5 |
| .25 | 4.1 |
| .29 | 4.8 |
| .35 | 5.7 |
| .40 | 6.5 |
| .46 | 7.5 |
| .50 | 8.2 |
| .61 | 10.0 |
| .80 | 13.0 |
| .91 | 14.9 |
| 1.20 | 20.0 |
| 1.50 | 25.0 |
| 1.60 | 26.2 |
| 1.80 | 30.0 |
| 2.00 | 32.8 |
| 2.40 | 39.3 |
| 2.70 | 44.3 |
| 3.00 | 49.2 |
| 1Cubic Inch = | 16.3934 Cubic Centimeters |
| .061 Cubic Inch = | 1 Cubic Centimeter |
| Top |
| Aircraft Trimming Chart for aerobatic flight |
|---|
| To test for: | Test procedure: | Observations: | Adjustments: |
|---|
| Control Neutrals | Fly model straight & level |
Use transmitter trims to achieve hands-off straight & level flight | Adjust devises to center transmitter trims |
| Control Throws | While flying apply full deflection of each control |
Check response rate for each control | Aileron High: 3 rolls in 4 seconds
Aileron Low: 3 rolls in 6 seconds
Elevator High: Allows smooth square corners
Elevator Low: 130' diameter loop
Rudder High: 30-35 degrees for stall turns
Elevator Low: Just enough to maintain knife edge flight |
| Incidence | Power off vertical dive, cross wind. Release controls when aircraft is vertical |
A. Model continues straight down
B. Model starts to pull out
C. Model goes nose down | A. No adjustments
B. Reduce incidence
C. Increase incidence |
Center of Gravity
(method 1) | Roll model inverted |
A. Lots of down elevator required to maintain level flight
B. No down elevator required | A. Add tail weight
B. Add nose weight |
Center of Gravity
(method 2) | Roll into near vertically banked turn |
A. Nose drops
B. Tail drops | A. Add weight to tail
B. Add weight to nose |
| Tip Weight (course adjustment) | Fly model straight & level upright. Check aileron trim, maintain wing level.
Roll model inverted, wings level. Release aileron stick. |
A. Model does not drop a wing.
B. Left wing drops
C. Right wing drops | A. No adjustment needed
B. Add weight to right tip
C. Add weight to left tip |
| Side Thrust | Fly model away from you into any wind. Pull into vertical climb watching as model slows down |
A. Model continues straight up
B. Model veers left
C. Model veers right | A. No adjustments needed
B. Add weight to right tip
C. Add weight to left tip |
| Up/Down Thrust | Fly model away from you into wind. Pull into vertical climb and release elevator. |
A. Model continues straight up
B. Model pulls up
C. Model pulls down | A. No adjustment needed
B. Add down thrust
C. Reduce down thrust |
| Tip Weight | Fly model away from you into wind, pull into small diameter loop |
A. Model comes out wings level
B. Right wing low
C. Left wing low | A. No adjustment needed
B. Add weight to left tip
C. Add weight to right tip or remove from left tip |
| Aileron Differential | Fly model on normal pass and do 3 rolls |
A. Roll axis on model centerline
B. Roll axis off to the side as roll command
C. Roll axis off to opposite side of roll command
| A. Differential Okay
B. Increase differential
C. Decrease differential |
| Dihedral | Fly model on normal pass, roll into knife edge flight. Maintain with top rudder. (Test on both right and left side) |
A. Model does not roll out of knife edge
B. Model rolls in direction of applied rudder
C. Model rolls opposite the rudder in both tests | A. Dihedral Okay
B. Reduce dihedral
C. Increase dihedral |
Elevator Alignment
(models with split elevators) | Fly model straight into wind. Pull into inside loop. Roll inverted and push into outside loop |
A. No rolling when elevator applied
B. Model rolls in same direction in both tests
C. Model rolls in opposite directions in both tests | A. Elevators correctly aligned
B. Elevator misaligned. raise or lower one half
C. One elevator half has more throw than the other. (Model will roll to the side with the most throw) Reduce the throw on one side, or increase on the other side |
| Pitching in Knife Edge Flight | Same as dihedral test |
A. No pitch up or down
B. Model pitches up
C. Model pitches down | A. No adjustment needed
B. Alternate cures;
1. Move the CG back.
2. Increase the wing incidence.
3. Drop the ailerons
C. Reverse the above. |
| Although these steps will work on any aircraft, they are for experienced pilots to trim aerobatic aircraft. If you are uncomfortable with any of these manuevers, get help.
Trimming must be done in calm conditions. Make multiple tests before making adjustments. Trimming chart courtesy of Russell Knetzger of Milwaukee, Wisconsin. Top |
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| Metric Conversions to Inches |
|---|
| Metric (MM) | American (Inches) |
|---|
| 1.0 | 1/32 |
| 1.5 | 1/16 |
| 2.5 | 3/32 |
| 3.0 | 1/8 |
| 5.0 | 3/16 |
| 6.0 | 1/4 |
| 8.0 | 5/16 |
| 9.5 | 3/8 |
| 13.0 | 1/2 |
| 25.4 | 1" |
| Top |
| Calculating Wing Loading |
|---|
| Wing loading is the key factor for good aerobatic performance! As a guideline, a Sports Aerobatic wing
loading of 19 to 25 ounces per square foot would be ideal. |
|---|
To calculate wing loading:
- Convert weight from pounds to ounces.
- Weight of model 5 lb. X 16 oz/lb. = 80 Ounces
- Wing Area in square inches.
- 600 sq. in. divided by 144 (sq. ft.) = 4.16 sq.ft.
- Divide ounces by square feet.
- 80 oz divided by 4.16 (sq.ft.) = 19.23 oz per square foot.
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| Mixing 2-stroke Nitromethane Fuel |
|---|
| Formula for 2-Stroke, Non-FSR engines, makes one gallon (128 ounces) All measurements by volume:
10% Nitromethane (12.8 oz)
12% Synthetic Oil (15 oz)
4% Castor Oil (5 oz)
Balance Methanol (95 oz) For high performance engines, increase Nitromethane accordingly. For use in very hot temperatures, use a combination of 8% Synthetic and 8% Castor oils for better lubrication. While this formula is used successfully by our local flyers, use at your own risk. Your mileage may vary. Top |
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