i used a OS .46AX, and it hauls balls! its around 140, with a tuned pipe, and the prop i have on there (at the moment i don't recall the size of the propeller). If i were to do build another one id probably put a larger engine in it. there's a vid on youtube of a guy, in Germany i think, who put a .91DF in it and that setup was capable of vertical takeoff!! for me takeoffs aren't bad, i just need to wrangle someone into holding the plane for me. they don't need to throw it, it has enough power to get enough speed in the few feet it drops when they let go. i have plans to make a little PVC launch rail set at like 45* and around 5 feet long, should work without a problem. I have had a failed takeoff with the arrow twice now, both times due to an issue with air bubbles in the line that caused the engine to lose power right after the toss, but i just put a new prop on and tried it again. it seems like the plane has enough throw, even on low rates to keep itself parallel with the ground. and ya know it lands on that skid without a problem, it'll throw tons of dirt all over your engine if you fly off a dirt runway like me.
