Hi
I have built this model for OS50Sx. What are your opinions on the flying characteristics? Will it fly well?
The weight is 2.5 Kgs without fuel and I am balancing it at the point where red covering ends on the wing. The tail looks very small in the pictures.... it is about 18% of the wing area.
Wing loading is 13.45 oz/sqft.

Thanks
Vikas

It will fly pretty good. However the weight will be the deciding factor. It weighs like a tad over 5 1/2 lbs. (someone check me on this b/c I just come up with that measurment out of my head). A saito .72 would be the power plant that I would have went with. Also I would fly it there but for some all out 3D the CG might need to be moved back a touch. The general design of the plane is a sure thing. It looks a lot like a Kangke Fun 50. All in all it looks real sharp.

Looks intresting... what is the wing span on it? The wing loading looks pretty good, I bet it'll do well. Something to watch out for, if you have problems in knife edge flight, try cutting off your wing tips. Planes like the Hype 3d and the Kyosho Flip fly alot better with the wing tips knocked off. As for the tail... you're right, it does look small in the picture. Did you counter balance the elevator and rudder? It's hard to tell from those pictures. I think it should do well though!

I would say the CG is way too far forward, and the fuz is not tall enough for good knife edge. Also the rudder and elevator dont look big enough unless they do have counter balances.

On the other hand, it does look good.

Yes, 2.5 kg is 5.5 lb. It may struggle a bit on the 50 sx, but should be able to hover with a decent prop.

Nice looking plane! The wingloading is down nice, should float well. Have to agree with some of the other poster's..could use a little more fuse side area for better knife edge. The tail looks kinda small and this could affect the location of the CG (it moves it forward). Iwould balance the plane at 25% MAC for the first flight and start moving back from there.

I recently built a plane with the tail about 17% of the wing area and balanced the model at 35% ( my normal starting point usually no problems) for the first flight and had my hands full as soon as it left the ground. The plane is now balaced at 28% and that is as far back as i can get it and still maintain pitch stability. The plane does still fly very well. Your stab looks like it is farther back from the wing than mine was, so this should help you somewhat. These are just my opinions.

Hi all
Thanks for the opinions.

Layne, the weight is exactly 5 1/2 lbs. I was aiming at 5 lbs. This weight includes a nose weight of 125 gms. which is required to balance the model at the end of the red covering. Getting the CG back a bit will help me reduce the weight.

The span is 56". Elevator is 66% of the total tail area. 50% behind the hinge line and the rest is counterbalance. Rudder is also counterbalanced. The blue is all rudder and half of the red area is the counterbalance.

If needed, I could add about 1" wide piece of balsa at the stab LE to increase the stab area, or may be at the TE.
Think Ill move the CG a little back.
Will be using 13*4 prop to start with.

Thanks
Vikas

And I am having 1.5 deg down thrust and 2 deg right.

Thanks

?????? not sure about this Lance. I would have thought removing wing tips improves the roll rate on thick wing sections. The knife edge will come from side area, and pitch in knife edge relates to the stab height in relation to the wing centre line. The closer the wing to the stab/thrust line the cleaner the knife edge.

Vikas....good effort mate - fly it and see what happens. If it has some bad habits build another and adjust to coorect it.

Simon, thanks and good point made!!

Hi all
flew the model yesterday.
The engine was very rich (just on the 3rd tank) but the power was not bad. The vertical was not too good with a rich setting....could just keep it hanging at full throttle.

Elevator is quite sensitive but rolls are really slow. I had problems in KE flight. It required a lot of down elevator and aileron to keep it on track. It also loses height in KE.
The slow speed flight is very good.

Any suggestions for improving the KE?

Thanks
Vikas

Glad to hear it flew well! There is alot of satisfaction in flying your own design......i hate arfs. To help the KE the only thing i would know to do is increase the fuselage side area.

Just for my curiousity where did you end up placing the CG?

I put the CG at about 25% at the root. At the tip it comes to 28% behind LE. The LE is straight with no sweep. No CG changes were required from the initial setup. However, I will try moving it back about half inch next time. This should help KE coupling too.

I could put a 1.5" wide sheet of balsa lengthwise at the bottom centre of the fuse to increase the side area. Will this work?

Thanks