sal2006

HI Guys,

Just bought a Katana, and I am putting an O.S 61fx motor in it, running on a 13x6 Prop. The engine weighs at 19.4oz. Does anyone have an engine that weighs about the same in their Katana 50? How does it fly? I know the landing needs to be a little hot, but that is something I am used to anyways. Also where did you guys mount the battery to compensate for the heavier engine?

Cheers Guys. Here is a pic of My old Katana that crashed due to a faulty radio on the Maiden flight, and yes, I'm not kidding

Stiks

With a 61 flys like a brick, I mean a dead stick that happened about 40 feet up the plane only glided probably 20 forward before hitting the ground. A bit of a rough landing and the landing gear will snap (weight of plane too heavy) and hopefully it won't take the gear plate with it. I don't think the battery will be enough to balance it either. The one I knew of had 3oz in the tail i think with the battery sitting right at the back of the canopy area.

The plane that I'm referring to was later fitted with a Mag52 and a few things here and there to reduce weight. Flew great and really improved its glideability. Actually it took a bit of work to get it down to land after that and dead sticks weren't a problem. Seriously if you want fun out of this thing don't use the 61 and try to save weight everywhere. When the owner of the one has enough funds we are going to do another one but with at the light weight gear and lightening methods straight up. Should be a blast then cause this thing can fly really well.

And also with the 52 can side mount it and not have to cut a bit hole in the nice cowl.

sal2006

I read on a few threads that alot of guys were using the saito 82, which is 85Grams lighter than my engine, its a can of catfood.....deadsticks might be a problem, but the reason the plane probably didn't glide that long was because it was probably a fraction tail heavy. I might make this plane a fraction nose heavy for better gliding. When i took off that previous katana i had with the 61, it took off so nice. I just don't understand how a 50 would pull it around. The 50 hardly pulls my harmon rocket.....and the katana is heavier. oh well. we will see how it goes. How did it fly without the deadstick???? and the 61 in it? and what brand 61 was it? was it an os?

Stiks

The 61 was a GMS so it is a little heavier than the OS. With the 61 the plane needed to be flown in the air at a higher speed to stop it from stalling. When we put the 52 in it it could be slowed down alot more without stalling. As for the tail heavy part could have been possible but we were in front of the first cg measurement and it was very soft in pitch movement not twitchy like when you have a rear cg problem.

The 52 had plenty of power to pull it around, it wan't fully unlimited but it went far enough that any higher is a waste of time. Can't give any feed back on its hoverability because the pilot is only just learning it now, but it would sit there on the 52 with some throttle stick left and the motor was only new and not properly tuned yet.

With the plane first up it weight just over 6 pounds with the 61. I think we ended up getting it down to about 5lb 6oz. If the LG had not broken it would have been probably another 2 ozs lighter.

Another thing that is a possibility of occuring is the bare weight of the initial model. One guy here in Oz went to his local store and weighed a couple of the 72" extras from CMPro and I think there was a 1/2 - 1 pound difference in weight between the kits. This is possibly an occurance in all kits so maybe the one I know of was a little heavier straight up. Not sure but next time we will be weighting everything and doing everything possible to get a light weight plane out of this katana. I will be posting what we do and what is achieved when we get to it.

sal2006

Okay,

I have finished the katana, and in all, with a 61fx, 5 dual ball bearing hitec servos, 2400mha battery at 4.8v and no lead added, also a slim line pitts muffler, it weighed 2.7 Kilos, which in my opinion will fly great with the bigger motor. I will most probably maiden it tommorow or on monday since i have a couple of touch ups to do. the balance with the 61 turned out perfect with the battery sitting underneath the servo tray and the balance point being 10cm's from the leading edge and 10cm's out from the fuselage. If anyone else has flown with the weight before, please let me know how it went, or in any case if anyone has flown a 2.7kilo model with a wing area of 500 square inches.
Cheers Guys