Stringer's required?

[Willja67 144]

I'm doing a full tear down on my plane and looking at anything and everything that can go away on the name of weight reduction (safely of course). What purpose do the stringers serve? Could some of them be eliminated?

Sorry if it's a dumb question but I have never heard the reasons for having the wood stringers. 

If i were to guess I'd say these might be reasons:

1. Improve the aerodynamics of the fuselage

2. Possibly structurally reinforce some tubes against buckling. 

3. Add some internal volume if a control line or something needs to be run outside the frame. 

4. Keep fabric from flapping too much.

5. Cosmetic

Anyway if i can lose a few ounces or even a lb or 2 that'd be nice.

 

[Allen Sutphin 705]

You are pretty close to being correct but I doubt a wood stringer would keep a 4130 tube from buckling.  Though in my present situation, I am probably not the one to comment on weight reduction. There is probably not one customer built aircraft that would be as light as the factory specs state. A lot of weight reduction measures depend on the mission of the aircraft. If one flys off a grass or paved strip, a bush gear, big tires, etc  are not really necessary, looks good, but are they necessary.Same for radio equipment, rural or back country flying, is a fancy com or xponder needed, when a simple handheld would suffice. Same with larger fuel tanks when or if your flights are a couple hours or less. Only you can say what you really need for your type of flying. I am an old map,compass,watch type so a Champ or Cub type panel is fine for me.  Sometimes the best weight reduction is the pilot losing a few pounds themselves. No offense intended. I am 140 so that comment isn't really worth much. Worry about the ounces, the pounds will take care of themselves.

[1avidflyer 1983]

I wouldn't remove the stringers.   And I would widen the fuselage and run the stringers against that extra tubing at the back of the door.  Stringers help to shape the fuselage, and also keep the fabric off the steel tubing which eliminates a bunch of finish tapes.  If Kitfox and Avid used them, they obviously serve a purpose.   Probably not structural, but other reasons.   JImChuk

[flywise 169]

I'm doing a full tear down on my plane and looking at anything and everything that can go away on the name of weight reduction (safely of course). What purpose do the stringers serve? Could some of them be eliminated?

Sorry if it's a dumb question but I have never heard the reasons for having the wood stringers. 

If i were to guess I'd say these might be reasons:

1. Improve the aerodynamics of the fuselage

2. Possibly structurally reinforce some tubes against buckling. 

3. Add some internal volume if a control line or something needs to be run outside the frame. 

4. Keep fabric from flapping too much.

5. Cosmetic

Anyway if i can lose a few ounces or even a lb or 2 that'd be nice.

 

As I am weight mad myself I can just give you the different items I found I could loose a lot of weight. If I were you, I'd start with the heavy before the lighter stuff..

Here a few things I got a lot of weight saving (not exhaustive list):

1. replaced heavy mech altimeter and VSI with electronic altimeter LED display (also shows VSI/OAT)

2. removed tubes in tires...1.5Lbs saving and easier field repair if punctured / also removed brake rotors for lighter ones/drilled holes

3.installed lightweight 406 ELTfitted with lithium battery

4.installed lightweight fibreglass tailwheel spring & light matco wheel with air tire

5. installed newer lightweight VHF radio / garmin SL-40

6. installed lightweight shorei li-fe main battery

7. recovered seat foam with lightweight fabric 

8. installed light & bright LED anti collision light

Also if you recover your plane, use Oratex covering...saves time and lots of weight

 

[Willja67 144]

Well Allen if I were you I'd have an automatic 90 lb useful load increase! I could stand to lose 30 lbs. I'm 6'1" and my ideal weight is about 195. The chart in the doctor's office doesn't account for guys like me i think. If I weighed what it recommends I'd be anorexic or have no muscle mass. I also happen to be somewhat claustrophobic. More especially i can't stand being in close proximity to other people for any length of time.

So I'm converting this to a single seater. No need to widen it.  It would only add unnecessary weight. 

As you can see sitting in the middle there are only maybe 5 inches on each side. All you guys who fly with 2 people in these early foxes must be tiny!  Even with an additional 3 inches of width at the shoulders I know I'd never be comfortable. And as you can see I'm not so fat that a sweatshirt can't hide it. 

I should add that i have a very specific vision for this aircraft that I know not all would agree with. That's fine i won't criticize your choices but I'm going to keep mine mostly to myself until I unveil it hopefully in time for Oshkosh. 

There are some choices that have been made that there's no going back from (at least not easily). I'm building this plane for me and I'm well aware that I'm probably destroying the resale value. So be it, it's for me after all. I originally bought it to have something to fly but it needed work and I find that I love working on it and making it my own. I never would have fit in it in its original form anyway. 

Oratex is going to be used to recover, unfortunately it probably won't net much weight loss since the original cover was unpainted polyfiber(polyspray only). It was a pretty nice cover job, whoever did it seemed to know what they were doing. 

It came with a Garmin G5 and some backup mechanical instruments, which have been sold off. Only the G5 a mgl engine monitor this radioand room for an iPad mini.  I'm not even going to have the panel go full width, just wide enough for the items mentioned. 

Edited 14 Sep 2019 by Willja67
Spelling

[Allen Sutphin 705]

Its really about what you want to do with the aircraft. A single seat Avid/Fox would be a unique thing, especially when converted from a two place. A lot of two seaters should in reality, be one seat anyway. Resale value isn't even in the picture when building a custom plane.  You just might be the guy to pull it off and have a one of a kind plane. As far as being 6'1" and 200 lbs, all I can say is "YES SIR". Go for it and good luck.

[akflyer 1427]

Others have converted these into a single seat airplane before.  Its all about the mission and making it YOUR plane that fits YOUR needs.  I am not one that puts much thought into resale.  I know I will never get out what I put into a project so I tend to hang onto my stuff till I completely destroy it one way or another.

 

[Allen Sutphin 705]

One probably shouldn't even consider resale value in dealing with E/AB aircraft. In general terms, one can buy a flying example for half of new kit price. Not good for kit providers. I don't know if anyone gets out what the have in one. One's time is of no value in selling.

[dholly 718]

Actually, there may just be a market for a single seat conversion. Plenty of -ahem- big boned {ass} guys wanting to fly around the patch that can't fit in an early Avid/fox with a friend. I bought my A+ kit after the larger of my hockey playing sons got in the Mk-IV with me. Even with staggered (or no) seat cushions it was not good. I am definitely not comfortable on a flight sitting sideways.