Fuse Side Area - how much do we need? Why?

[Dennis Toth]

Guys,
I'm in the process of redoing my electric TutorII to stiffen the fuse. This ship has lots of side area aft of the CG plus the fin/rudder. Since I'm redoing things I was wondering just how much side area it needs? I could slice off the top part of the fuse and add a simulated bubble canopy with the area close to the CG and maybe reduce or eliminate the fin/rudder. This ship pulls about 10 lbs and with the slab fuse uses a lot of amps to get through the pattern. My thought is by reducing the side area I could reduce the power (amps) needed, reduce the battery capacity and weight and maybe get the pull down a bit.

So what does side area do for a stunt ship, how much (% of wing area) is needed and were should the area be centered?

Best,          DennisT

[Eric Viglione]

Dennis - You might talk to Mike Ostella, I believe he kit bashed a few TutorII's into one of Bob Hunts Saturns? (can't remember which Hunt design for sure) Said the wing was close enough... I don't see why you couldn't do as you please with the profile shape.

As to the theory on line tension, well, I'll leave that for the guru's to sort out and just say offset and weight probably have more to do with line tension than other factors, otherwise a big jug like the T-Rex would rip your arm off.  I don't doubt the effect on power use but don't know enough to point you in any directions there.

EricV

[Garf]

I have a well used (abused) Tutor 2 that I am cleaning up to try a converted EVO 46 on. It has a LOT of power but the fuselage has a curve in it tword the outboard side. I think this thing might pull me over if I can't remove the curve. This might be a candidate for rudder removal.

[peabody]

Where are the Carolina guys when we need them? They created something called: TEOSAWKI (The End Of Stunt As We Know It) which was/is , essentially, a combat plane with gear....flew pretty well....
Not so many appearance points...


Have Fun

[Brian Hampton]

I designed a model with a very long tail moment (21 1/2" hinge to hinge) and deep rear fus for lots of side area with a particular thought in mind which worked as hoped. Flying in a brisk breeze it kept me amused watching the nose gradually yawing in as it went downwind then yawing out on the upwind side of the circle. Line tension felt fairly constant both up and downwind.

[john e. holliday]

I beleive that is the reasoning behind Dave Trible's Shameless that I flew for a few years.   

[Brett Buck]

Guys,
I'm in the process of redoing my electric TutorII to stiffen the fuse. This ship has lots of side area aft of the CG plus the fin/rudder. Since I'm redoing things I was wondering just how much side area it needs? I could slice off the top part of the fuse and add a simulated bubble canopy with the area close to the CG and maybe reduce or eliminate the fin/rudder. This ship pulls about 10 lbs and with the slab fuse uses a lot of amps to get through the pattern. My thought is by reducing the side area I could reduce the power (amps) needed, reduce the battery capacity and weight and maybe get the pull down a bit.

So what does side area do for a stunt ship, how much (% of wing area) is needed and were should the area be centered?

Best,          DennisT

   I doubt that it makes a lot of difference in this case (since even when you stiffen it it will be moving all over the place in yaw). But in general, you want side area to control the yaw angle, and if you can control the yaw angle better, you can use more "power". That's one reason my airplane is built, like my mentor says, like "3 billboards flying in formation" rather than a ersatz '59 Caddy tailfin. It's passive yaw control, as opposed to active like Al's rudder (a feedforward) or whatever Igor is doing.

    Brett

[Dave_Trible]

Thought I was going to sit this one out but my name came up so I'll share some I've learned on this topic.  Two aspects- frontal flow which I haven't spent much time on and side force winds where I have spent more time.  There sure is much fertile ground here yet to be plowed for someone interested. Frontal flow is the study more about spiral flow off the prop, complicated by that fat wing right in the middle gumming up the works. Side force is more about flying stunt in the wind. My Shameless is a good all-weather  airplane working off an area distribution scheme of about 25/75 percent fore and aft of CG.  After that you rely on offset, rudder and momentum keeping the nose out during maneuvers.  My updated scenario places the airplane in a stiff breeze, in the vertical, say top of the vertical eight or top of #3 loop in the clover. What is that 75% doing for me now?  Not much good-lifting that tail up and nose in at me.  In short,  move it forward (the area I mean).  Think Detroiter. (Or Max Bee)
Dave

Addendum-I ran out of time and so really chopped out my reply, sorry.  Dennis, I'm curious in that you express how hard the airplane pulls.  That could absorb power if caused by yawing or crabbing way to much.  That might be too nose heavy,  a lot of motor offset, rudder offset or the lead outs way too far  back.  I'd be interested to know if the pull falls way off above 60 degrees. If it does I'd suspect one or more of the causes above.  It wouldn't hurt at all to trim off some rear fuse area.  That would make it more nose heavy though so don't be afraid to glass/ carbon back there for your stiffening.  Trimming area aft of the CG probably won't help your fuel mileage nor diminish the level flight pull.  It WOULD help line tension above 60 degrees.

[Larry Fernandez]

[quote author=Brett Buck  That's one reason my airplane is built, like my mentor says, like "3 billboards flying in formation" rather than a ersatz '59 Caddy tailfin. It's passive yaw control, as opposed to active like Al's rudder (a feedforward) or whatever Igor is doing.

    Brett
[/quote]

Soooooooo
I figure, if "three billboards flying in formation" is good, then "4 billboards flying formation" should be better.

Larry, Buttafucco Stunt Team