Originally Posted by gdwyer
Hi there, I hope someone can help me....
I have converted a BH Glasair 120 to EP, using a Hacker A60 18L and an Masterspin 99 opto which was previously underpowering a 180 size edge 540.
I am using a 12s setup, I have an 800g setup (2x2500) and 1kg setup (2x3300) and while tried out a 22x12 mejzlic prop (M, which suggested 10kg of thrust using the "tied to a tree" test.
Great performance with this, although the plane is 6.5kg with the 1kg lipos, the recommended weight is 5.2kg
However very poor ground clearance with the prop here and I snapped shaft and broke prop on a heavy landing.
I have put on an 18x8 mejzlic prop, it tachos at 9,000 rpm full tilt but only pulls 4kg on the restraint.
I see gas versions use this prop with success, not sure how it will handle an extra 1.3 kg
I am worried about trying out the prop, can anyone guide me as the proper thrust / weight or suggest a prop? Is there an online calculator I can put in all the info?? Any help or advice would be much appreciated.
Uh Oh
Try to find out if you can pick up an APC-E
ELECTRIC prop
. These electric props have a much thinner blade, and are supposed to be slightly more efficient than props for the gasoline (Petro) or alcohol engines.
But, the important part, those thing electric props will often break on a noseover before the motor shaft does.
Take a look, at least in the USA anyhow.
http://www.apcprop.com/SearchResults.asp (Click on "Thin electric props".)
http://www.aero-model.com/Hacker-Bru...60-Series.aspx
http://www.aero-model.com/Hacker-Brushless-A60-18L.aspx