I used 1/8" birch ply with no reinforcing angle on the bottom. You certainly wouldn't want to put anything heavy back there so a strong floor isn't necessary. I am sure light aluminum would also be fine.
Per ideas from this forum, I am going to put a zipper, or probably a velcro opening in the back of my baggage sack to access the extended area for longer items like fishing poles, etc.
I think the fabric in the Kitfox is cordura. We bought and old sack from a KF 5 and extended it with fabric gotten off the web. We're using thin plywood as the floor to rest the baggage sack on. If you are good at sewing you could make your own. Here's a link to cordura fabric.
Thanks Tommy, sewing isn't my strong suite but I may be able to make some thing work. As for the link you supplied me, what is the difference between 30 and 1000 denier? Is that similar to cotton weight?
Also thanks for the info about the floor boards Jim. I guess 1/8th birch ply should do. Next time I fly home I'll try to measure up how much I need to order. I may do the sides with the birch ply as well instead of fabric. Something to think about. I do like the zipper idea for a number of reasons too.
If you do the cordura fabric go with the 1000 denier (heavier weight). Also go to sailrite.com, they have a video showing how to sew a zipper on a radius and sell oversize zippers. Not too hard to make a cargo bag, I did it.
I made an aluminum angle frame for my extended baggage area. It is made to fit the various tabs that were welded on the baggage area tubes.
The frame is then bolted to the tabs. Inside the frame I use two pieces of an aluminum honeycomb sheet (about 3/16 inch thick) that is cut in the shape of the angle iron frame.
The floor is made of two pieces (cut lengthwise) so I can easily remove them when it is time for my annual.
The weight of the whole assembly is about one pound heavier than the balsa honeycomb floor that came with my kit.
The honey comb is strong enough for me to stand on, which I often did when I had the turtle deck removed and was working on attaching the windshield.
I couldn't find a picture of the honeycomb but I have a picture of a balsa honeycomb that fits the frame I built but is used in another Series 7 with the extended baggage area.
Josh,
My project is a IV so the baggage area is a bit smaller and max. baggage wt. is a bit lower. I used a foam fiberglass lay-up for the floor, but you have to like to work with fiberglass for that. The frame is similar to WarEagles, but I cut slots in the angles about every five inches so I could strap the side fabric to the floor using velcro straps. I have an upholstery sewing machine so sewed my own. My goal was light as possible and though I used cordura, I found it came in three weights and bought the lightest. I have done some significant air camping in the past and never had anything back there that would puncture the light weight stuff. Then one other thing I did was make some tabs cut from some 4130 strap that fit under the screw heads that secure the floor. I drilled holes in each end of inch an a half lengths and bent them about 45° This will enable me to use nets or straps to secure the heavier items forward in the baggage area and the light stuff like the down sleeping bag will go in back. I modified my W/B spreadsheet to have two arms in the baggage area to be able to calculate W/B based on where various things are stored and secured. This is how it is done in the really big birds.
Lowell
I needed 3/4" on the horizontal in order to have enough meat for anchors to the airframe tabs. I wanted 3/4" on the vertical to get the strength for resistance to bending. I wanted to be able to stand on the extended baggage area floor when the turtle deck was off and I was working on the plane.