SAMAA Proficiencies and Wing Grading tests.

Interested in practising the maneuvers for your next Wing Grading? THIS LINK will tell you all about it. Open the Proficiencies folder and select the one you would like to practice.

There’s also a lot more info on that page, check it out!


Hobby Shops in the area


What Prop is right for my Plane?

This handy article from a UK website may help in selecting the ideal prop for your model engine. The sizes are approximate starting points only, so make sure to always consult the engine’s Manufacturers instructions as well.


By Chris Hinds

While all engines produce power the Propeller is essential to transmit this power. A more efficient propeller will transmitmore power to the air. In the UK the most commonly available propellers for I/C engines are:

  • Master Airscrew
  • Bolly
  • Kyosho
  • Graupner
  • APC
  • Precedent (Smart & Airflow)
  • Menz ‘S’ and ‘Ultra’
  • Mjenlik

Of these propellers Menz ‘S’ and Precedent’s ‘Smart’ range are suitable for large engines, these are wooden propellers so tend to break more easily than composite propellers. Mjenlik propellers are also suited to large models and are Carbon Fibre propellers. APC propellers are composite propellers and are excellent for most uses, they are not robust enough for beginners however. Graupner and Kyosho propellers are also composite propellers and are well suited to beginners, as a matter of preference I prefer a Graupner propeller. Kyosho props are a mildly quieter design than Graupner however. Master Airscrew props are noisy, inefficient propellers and their only redeeming feature is their strength against ground impacts – only buy if there is nothing else.

A table of my suggested propeller sizes follows.  It would be fair to say that my recommended props are often much larger than those typically used in the USA but this helps significantly with noise reduction and therefore I will go with a larger prop.  The engines will not bog down with these props, they just won’t quite develop all the power they could.  Though to be fair we do overpower anyway.  Prop sizes are only slightly above US recommendations.  If you field is noise sensitive (as many are) then head for one of the large sizes.

Engine Size
Ideal Prop Size
Propeller Size Range
Engine Type
Ideal RPM Range
0.10
7×4
7×4~6, 8×4
2-Stroke Glow
14000~16000rpm
0.15
8×4
7×5~6, 8×4~6
2-Stroke Glow
14000~16000rpm
0.25
9×5
9×4~6, 10×4~5
2-Stroke Glow
12000~15000rpm
0.32-0.36
10×5
9×6~8, 10×5~6, 11×4~5
2-Stroke Glow
12000~15000rpm
0.40
11×5
10×6~8, 11×5~7, 12×5~6
2-Stroke Glow
11000~12000rpm
0.46
11×6
10×7~9, 11×6~8, 12×5~7
2-Stroke Glow
10000~12000rpm
0.53
11×7
10×8~10, 11×7~9, 12×6~8
2-Stroke Glow
10000~11000rpm
0.61
13×6
12×8~10, 13×6~7, 14×5~6
2-Stroke Glow
9500~11000rpm
0.75
13×7
12×9~11, 13×7~8, 14×6~7
2-Stroke Glow
9500~10500rpm
0.91-1.08
14×6
13×10~11, 14×6~8, 15×6~8
2-Stroke Glow
9000~10000rpm
1.20-1.35
16×8
15×8~10, 16×8~10, 17×8
2-Stroke Glow
8500~9500rpm
1.40-1.80
18×8
17×8~10, 18×8~10, 20×6~8
2-Stroke Glow
8000~9000rpm
2.10
20×10
20×10, 22×8
2-Stroke Glow
8000~8500rpm
 
Engine Size
Ideal Prop Size
Propeller Size Range
Engine Type
Ideal RPM Range
0.26-0.30
10×6
10×5~7, 11×4~5
4-Stroke Glow
10000~11000rpm
0.40-0.45
11×6
11×6~7, 12×5~6
4-Stroke Glow
10000~11000rpm
0.48-0.56
11×7
11×7~8, 12×6~7, 13×5~6
4-Stroke Glow
10000~11000rpm
0.63-0.72
12×7
12×7~9, 13×6~7
4-Stroke Glow
10000~11000rpm
0.80-0.91
14×7
13×8~11, 14×7~9, 15×5~7
4-Stroke Glow
10000~11000rpm
1.00-1.20*
14×8
14×7~8, 15×6~10, 16×6~8
4-Stroke Glow
9000~10000rpm
1.40-1.50**
16×8
16×8~12, 17×8~10, 18×6
4-Stroke Glow
8500~9500rpm
1.80-2.00
17×8
16×10~12, 17×8~10, 18×8
4-Stroke Glow
8000~9500rpm
2.40
20×8
18×10~12, 20×6~8
4-Stroke Glow
7500~8500rpm
2.70
20×10
20×8~12, 21×8~10
4-Stroke Glow
7500~8500rpm
3.00-3.20
21×10
20×10~12, 21×8~10, 22×8
4-Stroke Glow
7500~8500rpm
 
Engine Size
Ideal Prop Size
Propeller Size Range
Engine Type
Ideal RPM Range
1.40-1.80
16×8
16×8~10, 17×8~10, 18×8
Gas
8500~9500rpm
40cc
20×8
18×10~12, 19×10, 20×8~10
Gas
6500~7800rpm
45cc
20×10
20×10~12, 21×8~10, 22×8
Gas
6000~7500rpm
50cc
21×10
20×12, 21×10~12, 22×8~10
Gas
6000~7200rpm
60cc
22×10
22×10~12, 24×8~10, 26×8
Gas
6000~7200rpm
75cc
24×10
24×12, 26×10~12
Gas
6000~6800rpm
100cc
26×10
26×10~12, 28×10
Gas
6000~6500rpm
150cc
32×12
30×10~12, 32×10~12
Gas
5500~6000rpm
200cc
34×11
32×12~14, 34×10~12, 36×10
Gas
5000~6000rpm

*The Yamada FZ120 is very powerful so a 16×8 is advised as a minimum, 15×10 being an alternative.

**The Yamada FZ140 Limited is more powerful than a Saito 180 so use the 1.80-2.00 prop sizes as a guide.

The figures are merely estimates – do not take them as gospel they are merely a rough guide.  As aside notes:

  1. The 3W and Desert Aircraft petrol engines are very powerful for their size and larger props should be used such as a 28×10 on a 100cc Twin from these manufacturers.

  2. I generally like to prop the engine in the RPM ranges above, to develop power without excessive noise levels.  In order to meet the UK limits a sensible mounting system (I like the Dubro Mounts) and an APC or similar propeller should be used, provided the manufacturer’s silencer is adequate.  Of the engines I have come across, O.S., Irvine and MDS Silencers are adequate without extra silencing fitted.  The O.S. silencers are the best of the standard silencers though.