What sequence to do you install your cowl, top or bottom first

[petersb]

Problem fitting RV7A cowl using Vans hinge system

I have completed most fabrication of my RV7A. I now have to attach the hinges.

With the bottom cowl installed first I am having difficulty installing the top cowl as the rear hinges jam. The only way to install the top cowl is to line it up slightly forward then slide it back, however, this cannot be done due to the horizontal hinges on the top and bottom cowl.

I can see great paint damage in the future trying to install it. I did have screws on my old RV6, however that also chipped the paint around the screws, thus my attempt on the RV7A to try Vans attach method.

Any comments on hinge locations, installation sequence etc.?

Peter

 

[Pmerems]

Please give more detail

Please explain you problem with a little greater detail.

 

[robertahegy]

Never had any issues. My top cowl just sat straight down on the bottom half. Did you give the hinges a slight bevel to allow them to engage easier?

Roberta

 

[petersb]

Never had any issues. My top cowl just sat straight down on the bottom half. Did you give the hinges a slight bevel to allow them to engage easier?

Roberta

Yes, they are beveled where the hinge curves as per plans. How much is yours bevel

 

[flyboy1963]

sequence...and....side etc.

I seem to be able to set one side into the hinge line, then of course, the back is a bit hung up, but can usually pop it into place on the first side.
then,.....it's a HUGE help to be able to stick my arm in the oil door, and carefully lower the second side down, while pushing it from the inside, or outside as needed to mate with the side hinge.
If I was building a new cowl, I'd recommend at least 2 access doors, for reasons like this, pre-flight inspection, battery charging etc.
( how the lower cowl goes on, mates with the baffles at the front etc. I don't even want to talk about! 20 minutes of cursing and scratching!)

 

[jay.pearlman]

forethought

In hindsight, perhaps camlocs across the rear of the top cowl would ease a lot of the issues. It in never too late. Skybolt products are really well made for this application.

 

[Snowflake]

The only way to install the top cowl is to line it up slightly forward then slide it back, however, this cannot be done due to the horizontal hinges on the top and bottom cowl.

On my -6, which I believe is functionally identical to your -7, this is not the case. I can lower my top cowl onto the lower, fully-installed, cowling, and the horizontal hinges line up (along the sides of the cowl, and along the back of the cowl across the top of the fuselage). The curved part at the ends that wraps down the sides does not sit in place, but it does come down if I flex the corner of the top cowl in and out a bit, working it down bit by bit until it all snaps into place on the side away from the oil door. Then I go around to the other side, and do the same wiggle, but with help from one hand reaching through the oil door. I agree, there is no one path that will get this to all fall into place in one pass.

I can see great paint damage in the future trying to install it. I did have screws on my old RV6, however that also chipped the paint around the screws, thus my attempt on the RV7A to try Vans attach method.

Unfortunately, you've chosen a path 180 degrees from most people... Finding problems with the hinges, they've all gone to screws for the awkward parts. I'd like to replace that top rear hinge on mine with Skybolts, I think it would go together a lot easier. As someone else pointed out, it's not too late...

 

[robertahegy]

I beveled the hinges about 30 degrees and I think I beveled all of the edges on the cowl half. I did them on a compound angle so they would drop in as well as slide in. Just do the leading half of the hinge to keep things tight once the cowl is in place. I did need to spring out the aft corners when lowering the cowl down, but it was an easy task done by myself.

One thing to keep in mind when installing the hinges is to set the ones mounted to the fuselage so only the rolled portion protrudes out beyond the skin. The ones mounted to the cowl should be set in so the fiberglass edge covers the hinge so you won't see the hinges once the cowl is in place.

Roberta