I've wanted to change the seat bottom 6B18-6 from a curved piece to an angle so my two piece seat cushions would fit better. It would also allow for the use of a booster cushion under the seats if necessary.

Thought about using a hinge after cutting the seat bottom in two pieces, but the solution was much easier. On my XL the distance to the top of the rear gear channel is 147mm. After removing the seat bottom, I noticed the the midpoint on the curve was 140mm. The co-pilot seat hasn't seen any use.

Figured out that a bend of 115 degrees would allow me to use the same piece of metal without cutting. Used 140mm from the top edge as the bend point. This makes the bend directly above the back edge of the gear channel, 7mm clearance, more than enough for the rivet tails. Added a .020 doubler, 90mm x 420 mm, 45mm flanges, double row of A4 rivets with the same spacing as the seat bottom. Here's the finished product ready to be installed.

Installed picture, perfect fit.

Another photo with some pieces of foam, not easy getting a good shot.

That's my story. Still waiting for the weather to clear, need to test some FWF modifications.

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Comment by Tim Juhl on March 19, 2013 at 9:27pm


Are you happy with your modified seat pan? Any opinion as to how comfortable it is compared to the original design?



Comment by Phill Barnes on March 24, 2012 at 8:01am

That looks a little easier to upholster. Top job Jake.

Keep posting mate.



Comment by Jake Reyna on March 21, 2012 at 7:33pm

I never understood the curved seat bottom, just makes building seats more difficult. Can't imagine that the seat bottom is structural. Been on the list for many years. Now that I'm at re-completion, I can spend some time on the small stuff.

Comment by Richard Rost on March 21, 2012 at 5:04pm

Looks good Jake! Another good idea for my heavily "researched" 650.

Comment by Richard Rost on March 21, 2012 at 4:55pm

Bob I always heard if steal one idea it's plagiarism. If you steal a lot of them it's research.

Comment by Bob Pustell on March 19, 2012 at 11:41pm

Nice! I have never really liked the "curved sling" seat bottom in the XL. I plan on two piece cushions, as well. Another idea to salt away for future shameless copying. Thanks.

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