SonexBuilders.net

Perhaps I am the only Sonex owner that finds the "piano hinge" system holding the cowl together and attaching it to the rest of the aircraft cumbersome. The rods always take significant pressure to get them all the way inserted. They bend easily if the slightest side pressure is applied. And, other minor issues that together make me think there must be a better way. It would seem some sort of clamping/buckle system would be much more convenient. Or, if anyone has another idea I would love to hear about it.

Thanks for any comments!
Aldo - Sonex 0954/Aerovee/N521NB

Some people have done a horizontal cowling split modification and used camloc or other quick release fasteners in lieu of the piano hinges. You can do this mod retroactively but it takes a good deal of fiberglass work.

I had seriously considered this horizontal mod where the top is one piece and the bottom another. Many feel it looks better.

As it is, I went with the plans. I agree that the piano hinges can be a pain. I keep a pair of vise grips handy and use those to grip the ends of the piano wires when I remove them. I usually grip them with a piece of paper towel wrapped around the end when I insert them. After awhile you get used to it and the hinges loosen up a bit.

Jake

Have seen guys chuck the pins in a cordless drill and "spin" them in. With a dab of oil on them that will help them loosen up a bit.

Aldo. I find the only way to make this job easy is to remove and replace the pins in exactly the same sequence each time.

To install. I do. 1/ Left side (only due to naca duct and tab for screw under prop), 2 / right side, 3 / the top centre, 4 / 2 pins bottom rear, then 5 / the long lower centre pin. Finally camlocks across the top and front screw. The reverse for removal. It now only takes me a few minutes either way now.

Be careful not to bend the hinge loops inserting the pin. If they are bent out of alignment it can be very difficult to install the cowl. They can be bent back into position fairly easy.

Steve 892

Did the horizontal split cowl on mine. Easy if making a new cowl. At fly-ins where other Sonex are present, like to pop the top off mine just to rub it into those who cannot quickly open theirs. Fact is almost never see a Sonex at a fly-in where the cowl is opened for pre-flight. There is info on the American Sonex Association web site, and mine which is slightly different can be found on the old Yahoo Sonex Builder's forum in folders section modifications to Sonex #1327, or can e-mail on request.

David A.

A friend gave me "THE Tool" for working with Hinge Pins. He took a piece of 3/8 aluminum dowel the width of your hand long, and drilled a hole in the end for the bent portion of the hinge pin (wire) to fit. This makes a handy "Handle" to pull the wire out and works great to push that last few inches of re-installation.
Happy Landings
John
N50NX