Big larry,

You are wielcome... I'm still somewhat of a newbie at this stuff myself... and I in NO WAY wanted to become long haired about it... and that's why I have stayed back a bit. But by process of osmosis I learned enough to get interested and got hold of the three basics:

1) Watts is the key
2) Gotta have a wattmeter
3) Motocalc will save you money and frustration


100 Watts per lb is good 150+ is really what I want for 3D... I'm trying to get 200 watts per lb on these small planes but can't quite get there seemingly... seems the 140-160 wtats per lb is the norm in this size plane.

I didn't catch that you wre suing e-propsw instead of slowflyer... yep as you saw big difference in these smaller planes... as you get larger, the plane's weight begins to flewx the blades an dyou must step up to an e-prop.

As emnm79 mentions, the Park 450 outrunner is a 12x6 motor, at least from the calcs and my personal experience with it. A good practice is to have a couple of each sie from say 10x3.8 to 12x6... hook up the wattmeter and check rpms.

Try the 12x6... you'll draw close to 17 amps and SHOULD drop to around 9.6 volts... 163.2 watts per lb. Very nice for that plane... If you are only drawing 13 amps now and dropping to 9.8 you are running 127.4 watts... Still decent but noticeably less power than the 12x6.

And some airframes require different props.... usually though bigger is better in these smaller planes... faster planes are more happy with smaller props, higher pitch and perhaps higher cells... foe example say a 9x6 on 4 cells (14.8 volt) may still draw 18 amps but have a pitch speed 20 mph more than the larger prop on less cells. A small pylon racer would benefit from this as the added weight is not an issue, speed is...


On yours prop it until it's right at or slightly above the motors max current at full throttle. Make sure that this figure is not too much for your ESC or batteries and you will be golden... this is assuming 3 cells which is pretty much the optimal votage for most of these smaller 3D airplanes.

As Trogdor mentions... now that you have discovered slowflyers props it likely that the batteries are your troubles... more amps may be causing the packs to drop considerably lower in voltage evening out the motors.

BTW... What is a HL 400XT? There may be a difference there too...