Darick's Sonex #1646

[Darick]

Need some advice from someone who has done their cowl. Following the instructions, I trimmed the aft edge from the landing gear the whole way up to the windshield to the fuel fill. The bottom lines up pretty good, that meaning a smooth transition from the cowl bottom to fuselage bottom. But the top wants to spring up about 1-1/2 from the windshield. If I push it down, then a bulge pushes out at the fuselage top at the windshield. Do I need to just keep taking off more? I'm afraid If I take off too much more, the distance from the hub to the windshield will be too short.



Notice how much the cowl is away fro the windshield...about 1-1/2".

[wlarson861]

Even after 5 years of flying I still have the same situation, although not as pronounced. When I put the cowling on I start with the center bottom pin and then the sides and bottom, then the top screws to hold the top down then lastly the upper center hinge pin. Doing it in that order the cowl goes on with less of a fight. If the bottom seam fits together well and transition to the fuselage at the bottom corner flows well then I would not trim any more off the rear vertical. I cant zoom in on your photo to tell if it is fitting with no radius at the corner. Try releasing the prop hub jig and see if the cowl moves forward, a good indicator whether the back has been trimmed far enough.

[Corby202]

I had to cut mine because of the same problem you are having.

http://www.mykitlog.com/users/display_l ... 1458&row=8

[peter anson]

Hi Darick, I think everyone has gone through the same problem. I had to just keep cutting the cowl back until it fitted. It was one of those things that looked wrong until it was suddenly right. The only advice I can offer is take it carefully - how about that for useless advice.

Peter

[Darick]

I needed a change until I felt ready to keep cutting the cowl. So I finished installation of the tail.

[Darick]

I continued working on the tail by completing the fairings and trim tab cable connections.

Right side...


Left side with trim cable in place...


Trim cable connection to trim tab...


It took three tries to get that Z bend small enough (where it connects to the trim tab). Bryan C. uses a simple phrase ...something like "thrice to get it right".

[Bryan Cotton]

We do it nice because we do it thrice.

I have Z bend pliers from my R/C days. Looks great.

[samiam]

Looks great Darick! Keep up the good work. Can't wait to see that thing flying soon.

Any chance you are planning to go to the Shreveport North fly-in? If the weather cooperates I'm going to take my dad over in the Champ on Saturday 6/17. That's close to you, you should stop by if available.

[Darick]

We do it nice because we do it thrice.

I have Z bend pliers from my R/C days. Looks great.

Somebody makes Z bend pliers!!?? Dad-gummit! BTW, thanks for the quote correction

Mike, yes, Shreveport is on my calendar.

[Darick]

Reference my cowl picture of March 27...I trimmed enough off the cowl to get the "spring" out of the cowl, instead of 1-1/2", now less than 1/2". All the hinges are in place and now working on the fuel fill door. I wish there was a better plan for the door, as the hinge is exposed according to the plans, and for esthetics it could look nicer.



In the above picture, the lower hole in the cowl is for access to the burp tube Curtis drain valve...see Feb.21 entry... I can open the fuel door and using a screw driver or similar tool, push down on the valve which allows it to fill with fuel which will be exchanged for fuel vapor if it exists.

This is not my idea and can't remember where I read about, but has been very successful in eliminating vapor in the fuel line.