attaching the cowl

acwrench · Post by **acwrench** » Sat Jul 22, 2006 10:28 am

Anyone out there have an alternate way of installing the upper cowl on a
-6 or -7? seen one install that eliminated the upper piano hinge and replace it with Dzus / Cam-Loc fasteners.

acwrench

JohnR · Post by **JohnR** » Sat Jul 22, 2006 12:44 pm

I'll be looking while at OshKosh this week and if I see anything interesting I'll take some photos for you and post them. Trying to decide how I want to do it whe nI get there someday.

Post by **Spike** » Sat Jul 22, 2006 3:01 pm

I have a good friend that has replaced the upper hinge on his 8 with zues fasteners and its beautiful. Ill get some pictures when I get back from Osh.

-- John

Bob Barrett · Post by **Bob Barrett** » Sat Jul 22, 2006 10:00 pm

I am building a RV-6A and I installed the cowl this Spring and I didnot read the print carefully enough. Although all of the RV's that have seen locally used the traditional piano hinge on the side and it was located right where the upper and lower cowl meet. My lower cowl was made so that the upper cowl overlapped it. If you read the print carefully it says to remove the portion that is over lapped on the outer parts of the lower cowl. I did not understand that and it clearly states not to remove the overlap on the air intake sections. I carefully installed the lower hinge on the lower cowl on the recessed lip. Then I carefulley drilled #40 holes through the firewall into the NACA ducts so that I could insert and remove the hinge pin through these holes. I then put the hinge pin in and drilled and clecoed the upper hinges half to the upper cowl. Then I carefully riveted the upper hinges to the upper cowl. I could with great effort remove and rienstall the right horizonatal hinge pin but no way could I get the left one back in. After a couple of months of trying various means to reslove the left hinge, I called my technical counselor and pointed out my error. I ordered quarter turn fastners to replace the horizontal hinges. I am continuing to use the the upper hinges but be sure to 90 thousand stainless steel hinge pins once you have aligned, drilled and clecoed the upper cowl to the fuselage! I was not using that and once I changed they go in and out relatively easy. I really like the piano hinges to hold the sides of the lower cowl to the fuselage. However I installed .063 2"X12" strips on each side of the bottom of the fuselage. I then put six nutplates on each side but four would have been adequate. I am using #8 roundhead stainless steel screws on the bottom. I am hoping to get my quarter turn fastners on Monday so hopefully I will have them installed before I leave for Oshkosh Wednesday. Read the prints carefully and telephone someone when in doubt!

acwrench · Post by **acwrench** » Sun Jul 23, 2006 12:30 pm

look forward to the pics when you get back from OSH

acwrench

Bob Barrett · Post by **Bob Barrett** » Mon Jul 24, 2006 11:14 am

If you do not want to use piano hinge, do not remove the inner lip on the lower cowl! Then you can use Zuis fasteners etc.

acwrench · Post by **acwrench** » Tue Jul 25, 2006 1:04 pm

I'll have to look at the cowl when the finish kit arrives

acwrench

JohnR · Post by **JohnR** » Fri Jul 28, 2006 9:07 pm

So are there problems with the piano hinge mounting method? I guess after looking at tons of RV's this past week the mounting method I thought looked best was the piano hinge. I plan on using it unless there is reason not to. Am I missing somthing or is it just a personal preference thing?

tshort · Post by **tshort** » Fri Jul 28, 2006 9:18 pm

The main problem I know of is wear and tear on the hinge eyes leading to failure or weakness / looseness.
Stu's RV-6 has lost two of the eyes off the oil door and there is play in some of the hinges on the cowl.
There are aftermarket hinges that are more durable with tighter tolerances.
One benefit of the hinge is a continuous joint - no possibility of bulging between fasteners.

Thomas

JohnR · Post by **JohnR** » Fri Jul 28, 2006 9:21 pm

Good information. Maybe I will look into options for the other hinge material as I get closer to that point. I do like the clean no hardware look ofthe hinges.

Thanks,

jim_geo · Post by **jim_geo** » Fri Jul 28, 2006 9:25 pm

Yes here is a picture from Oshkosh of an RV6.

captain_john · Post by **captain_john** » Sat Jul 29, 2006 6:21 am

The lower cowl is the one that is hard to attach. Wicked Stick's -4 is almost a 2 man job!

It is hard to finagle into position, defy gravity and hold there all the while trying to insert the hinge pins!

CJ

Bob Barrett · Post by **Bob Barrett** » Mon Jul 31, 2006 10:03 pm

The airplane on the RV-7 pictured used something similiar to cam lock fastners which were cheaper and he used the recessed ones which looks better than the cam-locks I used. I will try to send a picture Wednesday or Thursday evening.

svanarts · Post by **svanarts** » Mon Jul 31, 2006 11:07 pm

When you are fitting your cowl keep your engine/prop/spinner in mind. My engine sagged about 1/4 inch after flying for a short time. You may want adjust your cowl position a little for egine sag.

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