Original Seat Cushions Need to be Firmer

Discussion in 'Pitts' started by cwilliamrose, Jan 22, 2018.

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  1. Jan 22, 2018 #1

    cwilliamrose

    cwilliamrose

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    My S-2A has the original seat cushions. They are very soft but I don't know if that's due to age or it's just the way they were made. When someone sits on the front cushion it goes from about 4" thick to maybe half that thick and the sides of the cushions bulge out an inch or so, interfering with my feet and the rudder pedals. And this is at 1G, 3-4G would probably flatten the cushion almost completely.

    One thought is to have the foam replaced with something much firmer and put a layer of something softer as the top layer for a little comfort. The other option would be to just make something new/different and not use the original cushions. I'd rather use the originals at least until I start wearing chutes, then I'll need a system that works with whatever I end up with chute-wise. What do you S-2 akro types do to get people up to the proper height?
     
  2. Jan 22, 2018 #2

    Tomcat

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    When I was flying an s-2a I had to stack three different cushions in the back seat to get up high enough (I was wearing a back pack chute). I had different thicknesses and densities, I put the firmer cushions on the bottom and had a memory foam one for the top.

    For front seat passengers I always made them wear a butt pack chute plus firm cushions to get them up high enough.

    I occasionally fly an s-2b that has the stock cushion in the back and it is also very soft. It works just okay for acro but it's definitely not ideal. If it was mine or I was flying competition acro I would swap it out with something firmer so there was less compression and movement while pulling g's. Hope this helps.
     
  3. Jan 22, 2018 #3

    Aerobaticorsu

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    Flying mine with a seat parachute and original cushion in the back
     
  4. Jan 22, 2018 #4

    race38

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    Had a friend make me up a variety of thickness' to be able to adjust. I flew once with an original, while comfy for cross country, worthless for acro. My cross countries were to get to a contest. Always wore the chute. I figured I wouldn't forget it if I always put it on.
     
  5. Jan 22, 2018 #5

    PittsDriver68

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    Astronaut foam, otherwise known as confor foam, can be purchased in 3 grades of firmness. Highly recommended.

    I built a custom seat bottom from Divinycell aerospace core and topped it with an inch of confor foam. Sewed up a Sunbrella cover to make it look factory. Lets me pull 6G's without any compression.

    Oh, and you can add an inch of confor foam to your seat pack parachute to add a little comfort. If you have a Strong rig you can order that from them. Zips right on.

    Best of luck,

    Wes
     
  6. Jan 22, 2018 #6

    Larry Lyons

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    I will have to look as I don't remember the name but at SnF and Oshkosh an older couple sell the 3 layer astronaut foam already cut to about 24" x 24". It works lovely, I made a cushion with 1" of blue construction foam board and 1/4" plywood base to match my seat pack thickness. Use the foam seat cushion for cross country and exchange to the seat chute with a foam layer for aerobatics. However I don't have to worry about passengers! :D
     
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  7. Jan 22, 2018 #7

    biplanebob

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  8. Jan 22, 2018 #8

    cwilliamrose

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    Wes, do you remember the products you used? I found six different Divinycell products and there are three grades of Confor foam. I'd like to get it right on the first try if possible.

    My seat foam measures 4" thick with some wedges added outboard. Since the original cushions have zippered covers I can just fill them with new and different foam but I don't know what to buy. I figure 3" of something rigid and then some grade of Confor foam 1" thick plus a little for the wedges. In the front seat I may need additional height which I can add under the seat cushion (maybe) for Kathy. But if the seat was firmer we might be OK with the seat thickness as-is.

    It looks like I might have room for a seat pack chute in the back and almost for sure in the front. My S-1 project will not support a seat pack since there's not nearly as much depth in the cockpit. Great, three different chutes...... But this will be for another day........
     
  9. Jan 23, 2018 #9

    PittsDriver68

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    Bill,

    I use Divinycell H45 PVC foam for a lot of cores, and that is what I used for my seat. H45 is the lighter stuff at 3lb/cu ft. Easy to cut and shape as needed with common tools. Compatible with epoxy.

    H45 has compressive strength of 80psi, so it also provides some crush zone in a crash situation.

    For confor foam I think that I used the blue, or medium firmness, stuff. I will note that confor foam is temperature sensitive. On our cold New England mornings it feels like a board when your first sit down but as your butt warms it it flows out. You have to remember to give your seat belt another tug before takeoff.

    All of this is available from Aircraft Spruce.

    Best of luck,

    Wes
     
  10. Jan 23, 2018 #10

    cwilliamrose

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    Thank you Wes!
     
  11. Jan 23, 2018 #11

    ndlakesdreamer

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    Figure out how thick the cushion needs to be then use three equal pads of conformal foam. 1" of conformal foam is not enough, the stuff softens as it warms from body heat. If you use 1 inch you will be sitting on the hard stuff in about 15 minutes. The price difference between all conformal foam and some rigid stuff is less than 50 bucks. I made 6" cushions for my Ag Cats, 3 layers of 2" each. Best seat I ever sat in even after 10 to 12 hours.
    I like dealing with Hi Tech Foams from Nebraska. Nice couple to do business with and they attend a lot of aviation events.
    www.seatfoams.com
     
  12. Jan 23, 2018 #12

    cwilliamrose

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    I'm looking at a different mission -- short flights (mostly) and the need for the belts to stay snug. I'm afraid if I use all conformal foam the belts will get very loose and I'll slowly sink into the cockpit.
     
  13. Jan 23, 2018 #13

    ndlakesdreamer

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    Yes the soft foam moves so you don't have pressure points, the heavier densities take a long time to move. Call Hi Tech Foams and ask for a 6"x6" sample of the heaviest and sit on it for an hour. :eek:
     
  14. Jan 23, 2018 #14

    curtis

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    Bill,
    This the build up of foam that I bought from Hi Tech Foams. I thought this would have to much compression under acro. But so far it has not been a problem. I do ratchet down pretty good once time. The green take a lot to compress even warm. The blue does compress but not like the cheap white foam. The pink is mostly for soft comfort. So far I am happy with the build up.

    Curtis.

    IMG_3566.jpg
     
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  15. Jan 23, 2018 #15

    pigpenracing

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    I had the same problem in the model 12 with the Oregon Aero memory foam cushions. I went to Academy and bought a box of the really hard snap together foam pieces for a gym floor. I cut those and glued 3 together for the thickness I needed. I put that under the Oregon Aero cushion. When I sat in the plane my head touched the canopy. Once I buckled in and the the foam comformed my ass I had a few inches before touching the canopy. It didn't seem to smash down anymore once flying. You can also unzip your cushion and wedge a piece of that stiff foam under the existing foam.
     
  16. Jan 23, 2018 #16

    cwilliamrose

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  17. Jan 23, 2018 #17

    pigpenracing

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  18. Jan 23, 2018 #18

    cwilliamrose

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    Found some at the local Dick's Sporting Goods store..........
     
  19. Jan 23, 2018 #19

    Dennis Flamini

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    Last edited: Jan 23, 2018
  20. Jan 24, 2018 #20

    cwilliamrose

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    Thank you Dennis, I'll try to go by a West Marine in the next few days.
     

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