Aileron Control Interference

[Bryan Cotton]

Dale,
I think this is a lowered seat problem. I wish they had put the standard seat option in my Waiex plans.

[pappas]

I'll buy that, flag noted. To clarify, "The seat pan interference is something that I have seen in almost every legacy Sonex".." that I have seen". Exceptions could be for lightweight pilots but not this 200 lb lump!

[daleandee]

I'll buy that, flag noted. To clarify, "The seat pan interference is something that I have seen in almost every legacy Sonex".." that I have seen". Exceptions could be for lightweight pilots but not this 200 lb lump!

No harm, no foul. Bryan indicated that these were on the lowered seat mods but IIRC that pretty much became a standard part of the build early on. No doubt that there isn't a lot of room under the seat pan.

BTW, for whatever difference it may make both of the ones I referenced were center stick models without a lowered seat and that might make a difference as to the lump in the seat. Might be different with dual sticks and the "lump" sitting right on top of the control instead of next to it.

Cheers,

Dale
3.0 Corvair/Tailwheel

[Bryan Cotton]

One of the issues with the dual sticks is the top tube of the stick mount is just below the seat pan. That is my interference problem. Also note that my interference is not ailerons, but the pitch axis. I thought it would be good to put in Rick's thread because they are related.

My original tapered hat section was no good. Not enough clearance on the pitch pushrod. So, I made a 3 piece version. Here is one side installed, and one in my hand:

three piece half installed.png (557.06 KiB) Viewed 7168 times

I screw the other side down, and then put the top in. Those clecoes will become nutplates and #6 screws.

hat section 2 trial.png (564.28 KiB) Viewed 7168 times

I did a trial fit of the seat pan and it seems good. I am going to extend the other two channels as well, so it is supported more than just in the center.

[Bryan Cotton]

Here is my finalized seat structure. This adds 0.6 lbs at 75".

It seems like I have plenty of clearance now.

Edit: all the parts are made from 2024-T3 alclad. The right rib has a duct tape shim on top, to make everything coplanar.

[Bryan Cotton]

I've flown twice since I completed this. Once dual, once solo. I can really feel the seat pan is supported better and the controls are free. If I ever build another legacy Sonex with the lowered seat pan I will add this structure from the start.

[Area 51%]

I raised the back of the seat by an inch and made it out of .040. Never had a problem.

[Bryan Cotton]

I raised the back of the seat by an inch and made it out of .040. Never had a problem.

Sort of sounds like the non-lowered seat pan. Your solution also sounds like a good option.

[Area 51%]

I raised the back of the seat by an inch and made it out of .040. Never had a problem.

Sort of sounds like the non-lowered seat pan. Your solution also sounds like a good option.

I purchased an un-started, 10 year old Sonex fuselage sub-kit last Feb., just to get the ball rolling on this build. The plans show the common variety "raised seat" installation. It's amazing how much difference there is between that install and the "lowered seat". Not simply a relocation of the hinge half.

I didn't raise my seat to clear the control tree, but to clear the floor supports it was coming in contact with. I have pictures. bubblesinbpfl@yahoo.com

Just got parts back-ordered since November in the mail..........gotta go............Area 51% .