Cowling fasteners - stray from plans?

[lr172]

Originally Posted by UnPossible

On both my 7A and my 10, I used the hinges along the sides of the cowl, but on the my first plane (7A) I used Skybolts around the firewall..... and I didn't really like them.

I didn't like how the Skybolts hung down below the cowl, so that every time you put the top cowl back on, you risked scratching the forward fuselage paint. I also had a few that the retainer clips would not hold in over time.

On my more recent 10 build, I just used #8 screws, tinnerman washers and nutplates. Instead of $500 in Skybolts, I have about $20 in fastener costs. With a powered screw driver, it takes maybe a couple of minutes longer to get the cowl off, but there is nothing hanging down to scratch the paint.

After building a plane with both methods, I think I would use the screws and nutplates on any future builds.

While I have screws top and bottom on the 6 with 0 regrets, I made the 10 per plans (used SS hinges on bottom though) and I really like it. The 10 has the hinge pins ends outside and that is nice, as I never liked the idea of having them buried inside the cowl. Also no regrets on the 10.

Larry

[lr172]

Originally Posted by dmattmul

After 3 years my top cowl hinge pins where getting a little “sticky” even though I Boelube them almost every time. I decided to polish them with (below) and after doing this they slid in like buttered. I did get a lot of oxidation off when I did this. Highly recommend.

That is a GREAT idea. Mine are a bit of a pain to get out or in when cold.

Larry

[Draker]

I went with hinges, but I think it's entirely personal preference. Vans has you use screws on the bottom edge of the -7A lower cowl now. I think this changed with the new elastomer nosegear. They are a total pain. No matter how gently I screw them in, I end up stripping the philips heads when unscrewing. I need to start flying and stop modding, but one of the things I plan to do post phase 1 is to figure out a better attachment for the lower cowl.

[bjdecker]

I went with #8 stainless screws all around the cowl/firewall perimeter. The anchors are K1000-08s mounted under a 2" wide x .032" flange. A little Boelube (wax) on each screw keeps them from galling/stripping.

I am using small flange finish washers (39006F) under each #8 screw -- this protects the fiberglass from wearing through and has a nice clean look.

MS20001-P3 & P4 hinge material for the cowl sides. The difference in hinge widths allows the hinge to be offset to hide the hinge eyes and maintain edge distance.