Hi every body
I'm going to built a sr. falcon. whould you help me what will happen if i make it 10% larger??!!
and what about to 0 degree in dehidral ??
thanks for help.
reguards.

You'll be cutting all new parts, need a larger engine. If this is going to be a trainer, keep the dihedral in it for stability.

Hi, hamed-khorrami. Bigger is better from a flight stability standpoint. A 10% increase to the plan size should be a pretty easy enlargement, just be sure to bump yourself up an engine size to compensate for the extra size and weight.

Making the wing with zero dihedral will help the plane perform axial rolls and inverted flight a little better. It could change some of the the gentler flight characteristics a bit, though, as well. Just make sure you're looking for an aggressive sport plane instead of of a well-rounded sport plane before you build the wing without dihedral.

These are such good honest airplanes as designed. They are fun to fly and will take a beginner quite far into more advanced flying, before he becomes bored with it. The step up in size might be fun to do. 10% isn't really adding that much to it's size. I'm sure a .60 will still handle the plane well. I'm uncertain if there is a benefit in taking out the dihedral. I guess you won't know until you build it and fly it.

The size won't matter. Its a great flyer and if you blow it up a little, it will still be great. No dihedral will make it fly a little faster and roll a little faster but it will be a fun plane. I would consider putting a ST .75 or .91 on it though. Would be a fun bird. Heres mine with 4 engines.

Your plane is awsome! I have a Jr. falcon kit designed for .049 - .061 power, I wonder how hard it would be to make it a twin engine?...

thnaks every body.
yes i will fly it whith a OS .61 FX i think it is good enaugh !!
about the dehidral , i've decided to ake its wing in two parts, and madular. because it W.S will be 76"
so I should make it whith 0 degree in dehidral !!
I built a 69" wing span one which crashed while inverting!! here is its picture
appreciate any suggestion !!
[img][/img]

I'm uncertain if removing the dihedral will make the plane faster, or even if it will roll faster. Please splain this to me. However, it might make the rolls more axial.

A little CA and epoxy, good as new. Suggestions? Fly higher until you get the inverted thing learned. Leave room for mistakes and recovery.

Hi hamed-khorrami ,

The Nexstar was my first plane that I did most of my beginning learning on. The Sr, Falcon was my second plane. After flying both of them with the factory set dihedral, I modified the wings on both and flew them with 0 dihedral. I loved it! They both flew beautifully, each like a more advanced plane, especially the Sr. Falcon! To take the dihedral out of the already assembled wing on the Sr. Falcon, I used a sliding radial arm saw to exactly cut the wing joint in the center. I then matched the exact angle of the dihedral degrees on the saw and skimmed each wing joint with the saw blade to give a flat, 0 degree joint between the two wing halves. I drilled some holes in each wing half, eppoxied in some dowels to connect the wings and put a thick coating of epoxy on the entire wing joint surface. The new wing joint was very strong and the plane flew like a dream!
For me it was easier and much more excting to fly then flying a regular trainer.
Hope this helps.

tkeeg