Gtarling

Longsoar - sorry, I don't understand your '1.47A drain per 8.4V' statement. What people often fail to realise is that to get a glider of a certain weight to a certain height takes a set amount of energy - simple physics. Now, you can either deliver that energy over a short period or a longer period, but the result will be exactly the same. Until you've flown a large glider with an anaemic climb rate, you're not going to realise the importance of getting a high rate of climb to punch through the lower level turbulence as fast as possible. Now, you don't need a 'rocket - like' climb to achieve this, but you really want to have a climb angle of around 60 to 70 degrees if you can. From Motocalc, your B40-12S is going to be producing around 430 Watts on your 12 x 8 prop with a 3S 3000mAh Lipo pack. Apart from the fact that a 12" prop is on the small side for a model of this size, this is getting close to the 500W/15s limit for that motor, so if you have a climb exceeding 15 seconds duration, you also stand to be running into motor heating problems. My advice would be to return the B40 if you can and get either a B50-S or B50-L with the 3.7:1 gearbox and a 14" or 15" prop. If you're really stuck with the B40-12S, then give it a try by all means, but I feel you'll soon be thirsting for some more power!