Tobtech

My Feedback: (3)

I could use some ideas here. I have a Sig Cap 321EX and the supplied nylon screws for the cowl don't withstand the vibration. Just after one flight the glass cowl is starting to take off the heads of the screws. I thought about switching to metal screws, but I had a Extra 300 that I used metal screws to mount the glass cowl and the better screws would continually widen the mounting holes. Does anyone have any good suggestions for mounting a fiberglass cowl to these large airplanes?

daveopam

My Feedback: (9)

Best thing I have used , socket head screw threaded into a blind nut . With a 3/8" washer and a small "o"
ring under the washer. later daveo

MR G

I use #4 bushings and a #4 wood screw to attach my cowls with.

First, make a whole in the cowl big enough for a tight fit with the busshing.
Then epoxy the bushing into the whole(flange side of bushing out).
Cut, then sand the inside bushing flat and even with inside of cowl.


When you are done you will have a small epoxy ring around each bushing(Looks great I think).

I have never had a cowl develop any cracks around the bushings. It's easy to do and makes for
a lasting and stong hold on your cowls.
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Snowmass

My Feedback: (12)

The above ideas are good ones. But whichever you use, I'd also reinforce the fiberglass cowl around the holes. I do this by gluing a CA hinge (using thin CA) over the inside of each hole. Then re-drill the hole.

3dd

My Feedback: (6)

sig's nylon bolts are to weak and too small you might want to go to 8/32 nylon.socket heads work good but don't give if you nose it over very hard.

RaceCity

One word.....VELCRO

Get a strip at WalMart for a couple bucks...you'd be amazed.

No vibration damage....and the cowl is actually hard to get off!

It works like a charm.

'Nite

johnybravo

I agree with the gentleman who uses the #4 bushings and # 4 screws to mount the cowl. The # 4 bushings he is alluding to are manufactured by Sig and are made from high quality nylon. I use the same technique of drilling a hole just large enough to press fit the bushing into. I use 30 minute epoxy to glue the bushings in with and trim off the excess on the inside with a dremel cutoff wheel. I have used this system on 6 different cowled aircraft and have never had a problem with hole elongation, it looks great and it works. Try it, you will like it.[img]i/expressions/face-icon-small-happy.gif[/img]

b-mccor8

My Feedback: (3)

Here is an idea I love. Drill out the holes in the cowel large enough to slip the grommets from a servo through them. Don't make the holes to large. Then slip the brass inserts through them, and last but not least of course use a servo mounting screw to tightnen. A vibration free good looking install . I have done this with no cowl damage and no missing screws. also provides some give in a nose over.