Which Prop Should I Use?
All engines produce power. The prop (or to give it its proper name...
propeller) is a device that converts this power into forward thrust.
ALL PROPS ARE NOT EQUAL.
A more efficient prop will transmit more power, which gives more
thrust and produce less noise.
Below is the most common model aircraft prop for use on IC
engines.
APC are the
most common propellers for sport and 'pattern'
flying. They are made out of a composite material and are excellent
for general use. Graupner are also composite propellers and are
well suited to beginners as they are more resistant to the odd 'nose
over'. The square ended type also tend to be on the noisy
side. The standard Master Airscrew props are noisy and inefficient
propellers, their only redeeming features are their strength and
their cost. Master Airscrew produce a good quality, medium noise
and low cost prop range called the 'Scimitar' range.
What prop should I use? I hear you ask
Below you will find a table for common engine sizes & types.
For each engine size there is a 'preferred size' this
is listed as a good starting point for your model to pass the 82dB(A)
limit.
These figures
are gestimates
They are intended only as a rough guide |
Prop
Selection Charts |
2 Stroke Engines:
ENGINE SIZE |
PREFERRED SIZE |
ALTERNATE SIZE |
.049 |
6x4 |
5¼x4, 5½x4, 6x3½,
6x3, 7x3 |
.09 |
7x5 |
8x4½, 7x4½, 7x5 |
.15 |
8x5 |
8x4, 8x6, 9x4, 9x5 |
.19 - .25 |
8x6 |
8x5, 9x5, 9x6, 10x5, 11x4 |
.29 - .30 |
10x6 |
10x5, 10x6, 10x7, 10½x6, 11x6 |
.35 - .40 |
11x6 |
10x6, 10x7, 10x8, 11x6, 11x7,
11x8 |
.45 |
11x8 |
11x6, 11x7, 11x8, 12x6, 12x7,
12x8 |
.50 - .53 |
12x6 |
11x8, 11x9, 11x10, 12x5, 12x6,
12x8 |
.60 - .61 |
13x11 |
14x8, 14x10, 15x10, 15x12 |
.70 |
14x10 |
13x11, 14x12, 15x10, 15x12, 16x8,
16x10 |
.78 - .80 |
14x10 |
14x10, 14x12, 15x10, 15x12, 16x8,
16x10 |
.90 - .91 |
15x10 |
15x8, 15x12, 16x9, 16x10, 16x12 |
1.20 |
16x10 |
16x10, 18x5, 18x6 |
1.50 |
16x12 |
15x12, 18x10, 20x8 |
1.80 |
16x12 |
15x13, 18x12, 20x8 |
4 Stroke Engines:
ENGINE
SIZE |
PREFERRED
SIZE |
ALTERNATE
SIZE |
.45 - .48 |
12x6 |
11½x6, 12½x6, 12x7,
12x8 |
.60 - .65 |
12x6 |
11x7½, 11x7¾, 11x8,
12x8, 13x5, 13x6 |
.70 |
12x7 |
12x6, 12x8, 12x9, 13x6, 13x7, |
.80 |
13x7 |
12x8, 12x10, 13x8, 13x10, 14x6,
14x8 |
.90 |
13x11 |
12x12, 13x12, 14x10, 16x8, 16x10 |
1.08 |
16x6 |
15x8, 18x5 |
1.20 |
16x8 |
15x10, 18x7, 18x8 |
1.60 |
16x10 |
15x10, 15x12, 16x8, 16x12,
18x8, 18x10 |
2.40 |
20x10 |
18x12, 20x8, 20x12 |
2.70 |
22x10 |
18x12, 20x8, 20x10 |
3.00 |
20x10 |
18x12, 20x12, 22x10 |
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