How else am I supposed to pay for fuel
How else am I supposed to pay for fuel
Dorsal ~~^~~
Series 7 - Tri-Gear
912 ULS Warp Drive
My mk 7 seat pan is cracked and it isnt even fitted yet
I have been told that the seat lockers stiffen up the assy so I intend on fitting these, I will also fit some form of "butt block"!!! I will also add a layer of carbon composite in the likley stress areas.
Dave
Dave Holl
Building Kitfox MK7
Rotax 912ULS
i had the front lip of the seat pan pop over the tube and jam up the controls . lucky for me i was just taking the plane out for runup and taxi . didnt have the pan permantly installed yet , but it demonstrated an important lession . i certainly dont want that to happen in flight . ive installed the safty web strap under the left seat and attached the pan at the forward lip with adel clamps around the tube and screws with large area washers . the top aft lip i use wire ties
chuck
kitfox IV 1050
912ul warpdrive
flying B , yelm, wa
Hi, This an old subject but thought I would share how I handled this problem. See attached picture. Started with a 3" x 4" x 28 inch long pc of balsa wood. Glued a 1/4" × 3" × 28" pc of plywood to the bottom and a 1/8" × 4" × 28 pc on each side. Made a template from the bottom of the seat pan and started cutting and fitting. Epoxied in at 4 points. Seat pan  sits directly on these support blocks. I weigh 250 lbs and do not trust anything that is not solid to the frame. After all the trimming the total weight is 4 lbs, 2 lbs each. To me well worth the safety security. Note that the co-pilot side had more trimming done after this picture was taken.
Joe Leeman
K5
Rotax 912uls
Freedom, WI
Is there any risk of bending tubes? Or is the theory that spreading the load across 4 tubes lessens or takes away that risk?
Flying SS7, G3X, 912iS
https://mountainfoxbuild.wordpress.com/
The theory is I feel it much more important to keep the seat off the flight controls. I weigh 250 lbs and a good number of my co-pilots that might fly with me are over 200 lbs. I do not trust the flimsy fiberglass seat w/o something solid to the frame underneath. The only time that bending the tubes would be an issue is in a very hard landing. If this means bending the tubes under the seat i will just need to learn to make a softer landing. Or fix the tubes if I do bend them. More than likely I would survive the hard landing. If the seat breaks in flight and jams the controls I think the outcome is much worse.
But yes I did consider the possibility of bending the tubes.
I'm surprised that kitfox still supplies this seat design in new kits knowing that they could and have broke and caused an accident.
Joe Leeman
I'm going carbon-fiber first chance I get for the time to work the pan mold or if someone (hint hint) gets one done. Run a kevlar layer and the weight savings and strenght will be phenominal to say the least!
I have the straps under mine (Model 5) and I think Trent Palmer had a seat crack that bend a tube or maybe just caused some interference. Regardless the seat pan could and should be a great place for redesign for strenght and weight savings.
I like the block mold idea below but keep in mind, unless you spreadload those areas to the tube joints, you are asking for structural compromise mid-span of the fuselage tubes below those blocks.
Put the under seat storage box in. Both Kitfox and Murle Williams Aviation have them:
They help enforce the seat, prevent the seat from ever breaking and landing on the controls (Butt blocker), and provide some handy storage
underseat.jpg
http://www.murlewilliamsaviation.com