Hi all,

Recently built a electric plane with 400 motor but could not get hold of the recomended prop which was a 5.5 x 4. all my model shop had was a 5.5 x 4.5. How would this change the handling? Also i think ive worked out that the 5.5 bit is the length but what is the other figure for? One last thing, the plane feels a bit under powered could the wrong size prop be causing this?

Thanks

Joseph

Joseph,

Yes the 5.5 stands for the diameter (length) of the prop. The 4 or 4.5 is the pitch of the prop. The greater the pitch the higher the angle of attack that the prop is operating at. You shouldn't notice a big differance between the two props, although the 4.5 will probably have a little bit less thrust on the low end. If you want a little more thrust to start out with you might try a 6x3 prop, it should spin the prop at about the same RPM as a 5.5x4 and is pretty common.

Here is a sight that might help:[link]http://n-lemma.com/indoorrc/propcalc.htm[/link]

Happy Flying

Steve

Direct drive electric models often need to be flown in a special manner to get the best out of them. You need to let the model come up to speed and then modify your flying technique and maneuver presentation to keep the model's flying speed up high. Or if you do trade speed do it for altitude so you can get the speed back again by doing a maneuver with a diving entry.

Very tight pylon type turns and tight radius loops are big drag generators. Keep the maneuvers open and loose. Try to work with less throw. Large control throws are draggy as well.

In short fly it open and fast like a jet and it'll be fast. Try to horse it around like a 3D model and it'll be dissapointing.