SonexBuilders.net

Wanted to see what others have done on this. I'm not the lightest person in the world, but the seat pan on the Sonex sags so much, that it rubs on the elevator control stick a bit when moving the control stick fore and aft. I'm using the single stick setup. I was thinking of mounting some angle's on each of the fuselage side and run a 1x1 angle across for extra support. Any other suggestions?

The sling type seat does have to sag slightly to work but shouldn't touch the control rod. I'd suggest checking the seat dimensions and that you have mounted the hinges as per the drawing F-08. The lower rear hinge should be flush with the seat back. A small error there could cause extra sag. If that is the problem it could be fixed by fitting a new length of hinge to the seat which would be easier and lighter than fitting reinforcing. The seat is strong enough for any weight the Sonex can carry.

Peter
Sonex 894

Hi all,
We modified our seat pan by doubling up on the bottom and back full size. Much much stiffer, also getting in and out and kneeling in seat working on plane much easier. We added the dynon autopilot, had to add an angle on rt side seat edge full length. Space is tight under there especially the roll servo arm.
WaiexN143NM
Michael

I am also having issues with the seat pan hitting the rod. It is way better since I hacked off the trim spring mount. I am considering shimming the seat- with tubes riveted in. Here you can see tubes taped in temporarily.



Here is the seat pinned in place:


This seems much easier than hacking off the front of the seat for a new hinge, or redoing the hinge on the spar tunnel. Thoughts?

Hi bryan,
Neat idea. Do you think the tubes of that wall thickness will be ok? There is alot of force when you step into the seat pan. Earlier in this thread i posted about doubling up on the top and bottom sheets to stiffen thing up. Dave webber from dynon had his sonex on the flightline at osh years ago , and during show and tell told us this trick. Its very tight for space under there. When we added the dynon autopilot we also had to add a angle underneath along rt side with a cut out for aileron pushrod to stiffen things up. If we put 400 + lbs (2 adults) in the seat it needed all of this to elimnate sag and interference with the servo arm.
Its also nice and stable getting in and out of the plane. Still has enough give and hinge pins go in just fine.
So are you doing the cowl next? Sell your vertical cowl and pick up a horizontal cowl from sonex. You will love it!
WaiexN143NM
Michael

Michael,
I can stomp on the tubes and they don't crush. They are leftover scrap from a Basler kit. I may be foolish, but I have psyched myself up to earn the vertical split cowl merit badge.

I think it looks like a good idea. Also, I have noticed the cut out, on my single stick seat, is slightly wavy after having climbed in and out a few dozen times. So I've been thinking of using a doubler on the cut out area, much like the doubler on the fuselage side forward of the spar tunnel.

The tubes are riveted. It seems to work well. I stepped right on them getting in.