I was asked to do more prop testing with the HobbyZone Super Cub's brushed 480 motor to see how some of E-flite's props would stack up against the stock HobbyZone 10×8 prop and some GWS props.
The first graph shows the results for selected 10" props:
The second graph shows the results for selected 11" props against the stock 10×8 prop:
The last chart is an expanded view that shows all tested props at wot using a ThunderPower 2200, 11.1 volts – I would consider this the top limit of what can be powered through the stock ESC and 480 motor (HobbyZone does not certify this setup beyond the 9.6v NiMH; I do not recommend the Lipo setup). A number of Super Cub owners are using an 11.1 volts Lipo reporting no problems:
The Prop Load Factor is a number which shows the load a given prop puts on a motor – it's computed by multiplying the prop's diameter cubed times its pitch (thanks to Lucien Miller of Scorpion for this). All other things being equal, a prop rated at 8000 will require 50% more power than a prop rated at 4000; however, all props are not equal and you may see differences among props with the same diameter/pitch due to their designs.
IMHO there are two clear winners:
GWS 10×6 HD: I use this and it's a nice alternative to the stock 10×8, giving good thrust although at higher rpms; it's not a "power" choice but is more efficient that the stock prop, achieving about 8% more thrust for the same power input at higher watt levels.
E-flite 11×4.7 SF: I have not used this in flight but on paper it's a clear winner – achieving about 8% more thrust for the same power input at higher watt levels.
Is it worth it?
From an efficiency standpoint – yes. From a power standpoint? Less so. Don't expect to see dramatic improvements – the table below shows the difference is Thrust/Weight Ratios at wot assuming a flying weight of 25 ounces:
Propeller
Diameter
Pitch
Thrust/Weight Ratio
Total Watts @ WOT
HobbyZone 1080
10
8
0.88
143
GWS 1060 HD
10
6
0.80
105
EFL 1147 SF
11
4.7
0.95
141
EFL 1070 SF
10
7
0.80
140
EFL 1080 E
10
8
0.77
141
GWS 1180 SF
11
8
0.93
151
The GWS 1060 HD, while more efficient, is rpm limited to a lower thrust level at wot; however, the EFL 1147 SF is not and as such achieves about an 8% higher ratio at substantially the same power as the stock 10×8. However, this will not linearly translate into more speed – increase in speed, increase in drag, more speed to overcome increase in drag, etc.
I found the E-flite SF props to be stiffer than equivalent GWS SF props – this should translate into more effective thrust, as the E-flite props should hold their shapes better than the GWS SFs at high rpms.
Conclusions
Either the GWS 1060 HD or the EFL 1147 SF are good choices to try against the HobbyZone stock 10×8 prop, each for reasons stated above. Overall the E-flite 11×4.7 SF looks like a fine replacement for the stock prop.
Note: The E-flite 11×4.7 SF requires drilling out the hub slightly to fit the 480's shaft and requires a lock washer to keep it from slippng – the hub will not fit over the 480's nut.
The E-flite 10×8 E will fit directly over the 480's nut but will not clear the motor – this requires adding a second nut to the shaft to achieve clearance.
E-flite vs GWS Prop Tests for HobbyZone Brushed 480 Motor
I was asked to do more prop testing with the HobbyZone Super Cub's brushed 480 motor to see how some of E-flite's props would stack up against the stock HobbyZone 10×8 prop and some GWS props.
The first graph shows the results for selected 10" props:
The second graph shows the results for selected 11" props against the stock 10×8 prop:
The last chart is an expanded view that shows all tested props at wot using a ThunderPower 2200, 11.1 volts – I would consider this the top limit of what can be powered through the stock ESC and 480 motor (HobbyZone does not certify this setup beyond the 9.6v NiMH; I do not recommend the Lipo setup). A number of Super Cub owners are using an 11.1 volts Lipo reporting no problems:
The Prop Load Factor is a number which shows the load a given prop puts on a motor – it's computed by multiplying the prop's diameter cubed times its pitch (thanks to Lucien Miller of Scorpion for this). All other things being equal, a prop rated at 8000 will require 50% more power than a prop rated at 4000; however, all props are not equal and you may see differences among props with the same diameter/pitch due to their designs.
IMHO there are two clear winners:
From an efficiency standpoint – yes. From a power standpoint? Less so. Don't expect to see dramatic improvements – the table below shows the difference is Thrust/Weight Ratios at wot assuming a flying weight of 25 ounces:
The GWS 1060 HD, while more efficient, is rpm limited to a lower thrust level at wot; however, the EFL 1147 SF is not and as such achieves about an 8% higher ratio at substantially the same power as the stock 10×8. However, this will not linearly translate into more speed – increase in speed, increase in drag, more speed to overcome increase in drag, etc.
I found the E-flite SF props to be stiffer than equivalent GWS SF props – this should translate into more effective thrust, as the E-flite props should hold their shapes better than the GWS SFs at high rpms.
Either the GWS 1060 HD or the EFL 1147 SF are good choices to try against the HobbyZone stock 10×8 prop, each for reasons stated above. Overall the E-flite 11×4.7 SF looks like a fine replacement for the stock prop.
Note: The E-flite 11×4.7 SF requires drilling out the hub slightly to fit the 480's shaft and requires a lock washer to keep it from slippng – the hub will not fit over the 480's nut.
The E-flite 10×8 E will fit directly over the 480's nut but will not clear the motor – this requires adding a second nut to the shaft to achieve clearance.