Thorp Air Command - T18.net

IMHO, if you stick with a plans built (or close to it) frame along with a very high density foam, you will come out lighter and a better fit. By the time you take a "racing seat/boat seat" and send it to the chop shop (to fit), you will have spent more $$$ and invested more time. There is an outfit (can't remember the name right now) that sells seat kits (foam) for the T-18 (they also supply Vans).

RB

Well, I finally received my seat kits from CSA. They provide a nice complete kit, pretty much to plan, or close to it, BUT I was surprised to find that the seat tubing was 3/4 x 0.058 wall instead of what the plans called out. (1.0 x 0.095 wall, I think, or in that range.)

Should I be concerned?

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In theory, theory and practice are the same. In practice, they are not.

One year at PTV CSA had a fully upholstered seat sitting on a work bench. I picked it up and it was incredibly light weight ...a big plus ! If the seat has the aluminum sheeting for the back and bottom to tie the entire seat frame together I would not be concerned. I have not heard of ANY complaints about CSA seats.

RB

There are a few guys out there flying with seats made from aluminum lawn chairs. (see older NL) I actually had such an airplane for a while. They were pretty stout and very light. My point is that lawn chairs are pretty thin material, most likely not .05. I agree with Rich, i would not sweat it.

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Lee Walton
Houston, TX
N51863,N118LW
KEFD

Dick,

I think that with the mass of your ass, the seat material will not be an issue.


Jim Mantyla :-)

Excellent points. Yes, the upside is lightness. Lightness is good. Thanks.

Jim... the mass has gone up a bit... the winter was not kind to my ass.

DW

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In theory, theory and practice are the same. In practice, they are not.

I used CSA seats. They are great. The only thing I would do different is that the aluminium sheet folds to stiffen the backs should face foreward into the foam. I have trouble adjusting the seat to the rear seat position on the front seat attach points.I have a set in my album on this site.

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James Ball

Jt,
I just looked at your seat picks. You're right, on the back and bottom sheets, the bent up angles are supposed to face into the frame. You need to notch the corners at the angles so that it will clear the tube.
Lee

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Lee Walton
Houston, TX
N51863,N118LW
KEFD

Anyone have contact information for CSA. I have not heard of they and can not find anything on line. I would like to check them out. I have good frames, but need recovered.

Thanks, Keith

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Keith Schneider
Waynesville Ohio

Look on the main forum page, heading "our suppliers".

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Lee Walton
Houston, TX
N51863,N118LW
KEFD

OH!, That CSA, Thanks Lee.

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Keith Schneider
Waynesville Ohio

I just discovered that my purchased seat frames are 10 or 15 degrees underbent. Unfortunately they are now assembled.

Did I miss something in a newsletter? The drawing calls for 84 degrees. Is there some technical advantage to 75 degrees?

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In theory, theory and practice are the same. In practice, they are not.

Dick,
Most seats now are two part and most likely hinged. If yours are a single "L" shape then the advantage to a"righter" angle is allowing the seat to push back farther allowing more leg room.

These are "experimental" aircraft, the greatest variation between airplanes is usually in the cockpit.

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Lee Walton
Houston, TX
N51863,N118LW
KEFD

Right! Mine are CSA kit seats with the hinged back.

90 degrees would be a right angle. 84 degrees is what the drawing calls for. ~70 degrees is what my seats are bent to. Consequently, the seat back contacts the rear frame in any seat position.

Unfortunately I didn't check the angle before I put them together. I can't think of any good reason for underbending the frame except maybe to relieve the stress on the light hinges, which are "undersized" because they used 3/4 tubing instead of the 1" called for in the drawing. Did I miss anything?

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In theory, theory and practice are the same. In practice, they are not.

3/4 is standard (or at least typical) at this point.

The angle. .. My point was that a righter angle would lend itself to a taller pilot and a more obtuse and would lend itself to a shorter fella. As far as the reason, I'm sure you received an approximation from CSA. At this point you could out some "Williams" (as in Bill) and clamp the back to your bench or something solid and tweak another 10 deg out of it.

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Lee Walton
Houston, TX
N51863,N118LW
KEFD