S

Skyhook

Well Known Member
Several times last year I had to take down the cowl for oil changes and annual plus a couple of minor look-sees, and I am having a nasty time inserting those hinge wires.
What's the best lube for those things? I have been using dabs of axle grease and *sometimes* all goes quite well-- then every now and again, like this last time- inserting those wires was a trial.
What're you folks doing to ease that pain?? :eek:
 
Piano Hinges

Put in a set of cam locks on the bottom only in place of the piano hinges. I used three per side on my RV-6A and on my RV-10. I also put in three per side on an RV-8 that I co-built.

The cam locks work great and if you get the adjustable ones they make fitting cowl to the bottom plate you put on in place of the piano hinge attached to the firewall a snap. There is a little black piece of plastic that you remove from the cam lock after getting the depth adjustment set to where you want it. The best way is to screw in all the way out and then after putting the cowl on to just screw in the cam lock to the tightness of the fit you want and then VERY CAREFULLY disengage the cam lock. You don't want to screw out the cam lock depth while disengaging. Remove the bottom cowl, pull the black plastic tab and the cam lock is set for your particular adjustment. I found that the depth adjustment on the three per side camlocks were a little different because of the slope of the fit of the lower cowl.

Good luck,
 
My pins get kind of chewed up over time and have burrs on them. I'll run them over my scotchbrite wheel to clean them up and them rub boelube on them. It seems to help.

Karl
 
Boelube or just plain old candle wax

Believe it or not wax is a great lubricant and will stay on the hinge pins longer than grease - and less mess. Once you start the engine the heat will help evenly coat the pins. Now, my hinge pins slide in and out "like butta."

Notice that Boelube has a wax base...
 
How many hours do you have on the installation? Mine started out pretty stiff - removing them took a set of lineman's pliers in the first few months - but they eventually wore into place and are easily pulled by hand.

Another thing to consider if they don't get easier is how well the parts are aligned - if the hinge pins are actually pulling the cowl into position (so that they are pre-loaded), you will end up breaking hinge loops and they will always be tough to install. Hard to fix without removing and replacing hinges, so this comment is more for folks still building.

Paul
 
Another souce of tightness.

I embedded my hinge in epoxy/flox. Some got inside the loops. This made it incredibly tight.
I fixed this by chucking up a hinge pin and running this through the loops on the drill motor. I filed the end of the hinge pin to make a slight cutting face on it.

Kent
 
clean- n-up

As for the hinge pins between the top and bottom, clean them up with emory cloth. Then put them in your hand drill and run them in and out as far as you can several times. This helped mine a bunch........ ;)
 
bingorama baby

kentb said:
I embedded my hinge in epoxy/flox. Some got inside the loops. This made it incredibly tight.
I fixed this by chucking up a hinge pin and running this through the loops on the drill motor. I filed the end of the hinge pin to make a slight cutting face on it.

Kent
Click to expand...
got some micro in the eylets on one side and those microballoons will make pin installation and removal a bear. the drill trick works great...
and for stripped out phillips head screws i dip a wet screwdriver tip into dry micro balloons and it will almost gaurantee screw removal.
 
Don't be despair. I still remember in the beginning I needed to use a mallet to "hammer" in the pins between the top and the bottom cowl. The sharpened tip helped a little but it was "hard" to get the pin inserted, especially the last 3 or 4 inches (mallet was used for that). After ten to twenty hours flight time, the pins get looser. Now after 250 hours inserting those pins is easy and nothing has broken. Now the tedious part of taking down and installing cowls is removing/installing screws and not removing/inserting pins.

As advised by others, use wax, plier, mallet, or whatever (no oil unless you have already painted your cowl) to get the pins in and out. They will get looser over time.
 
You never know what kind of cool info you will find here.

cytoxin said:
and for stripped out phillips head screws i dip a wet screwdriver tip into dry micro balloons and it will almost gaurantee screw removal.
Click to expand...
Thanks, I'll use this trick soon.

Kent
 
What about the upper cowl to fire wall pins. I'm still having trouble inserting these. Any experience or suggestions there. I'm still not ready to throw in the towel and fit camlocs as I like the simplicity and economy of the hinges :)
Jim Sharkey
RV6 Tip-up
 
In my case I pop the right side firewall hinge loops together without fitting the rest of the hinges then insert the short pin. This is the tightest on my cowl. It is very hard to insert if I insert the left side firewall or side pins first. After this I push together the rest of the hinges and insert other pins, insert side pins, then finally the longer firewall pin. Just reverse the process for taking down. Your installation is different and you may find another sequence works better for you. If it is just very hard to install the pins, it will improve over time. If it is impossible to install, then you need something else.
 
Cam locks

Does anyone have pictures of your cowl who are using the cam locks mentioned in this thread. Just starting a QB but trying to learn all I can about various methods and techniques. I am not sure I know what a cam lock system looks like. Thanks
 
RVG8tor said:
Does anyone have pictures of your cowl who are using the cam locks mentioned in this thread. Just starting a QB but trying to learn all I can about various methods and techniques. I am not sure I know what a cam lock system looks like. Thanks
Click to expand...


Mike,

Jim Daniels in NM has a great site with good detailed photos of his installation. Helped me a great deal when installing mine as he worked out all the details and has great photos and measurements:

http://home.comcast.net/~jwdweb2/Cowl1/cowl1.html

Also, Randy Lervold has some good info on his site as well:

http://www.romeolima.com/RV8/IdeasProducts.htm#PRODUCT: Skybolt cowl fasteners

I did the Skybolt camlocs on my firewall and am really glad I did that. It's not as slick as the hinges, but it sure makes maintenance much easier. IMHO the way to go is camlocs on the firewall and hinges on the side. The Skybolts are a little pricier than normal Dzus fasteners, but that is because of their ability to be adjusted for length. This makes sizing easy - basically one size fits all for the most part and it allows you to have a perfect fit on the cowling without some fasteners being loose and others tight.
 
Top cowl pins.

I bent a loop (about 3/4 inch around) in the end of each. This helps to get a hold with the fingers or pliers. Can be used for both pushing and pulling. Also be sure to bevel the end of the pin, so that when it gets to the next loop in the hinge it will enter without hitting the edge.
After a year of flying and lots of remove and reinstall of the cowl, I can almost always remove and insert the top pins by hand. But I keep a pair of needle nose pliers handy.

Kent
 
Top cowl pins and holder

I bent the ends to fit them in a holder on the firewall. It makes insertion and removal much easier. I can think of another advantage of using cam locks. When engine is hot, the hot Oil filler cap may touch your forearm when removing right side pin. I always do it slowly and carefully so not to get burn.

IMG_8461.jpg


I used to have a GPS antenna shelf on the firewall. It interferes with the right side pin installation. Now I keep that part of the firewall pretty open.
 
The -9 I built was difficult because I got epoxy in the hinge eyes, but doing it a second time using the tricks I learned, the -4 has worked out well.

1. Keep the pins & eyes free of epoxy.
2. Bend the very end of the pin slightly to help it round the curve, & bend the whole pin to match its installed shape.
3. Most important bevel the end of the pin into a wedge shape, not tapered.

You can see the result on my blog.

I havnt lubricated them yet because its not painted. Should get even easier.

I have a right angle bent in the firewall pins and retain it by hooking them under a piece of glass bonded to the underside of the cowl. Similar to the firewall solution in the picture below.

Good luck,
 
I am appreciative of all the comments and help.

And I am learning something- usually do here. ;)

OK, so it'll be a total clean-up with deburring of the hinge loops followed by a wax coating. Excellent.

BTW, my -4 has ~470hrs on it and is really the magic carpet flying machine of my dreams.

As to the Camlocks, I think that will be a last resort move since I do like the smooth looks of that piano hinge set-up. I also think the piano hinge probably offers a bit more strength in those connections. Just a feeling.

Thanks again, all.

Jim
 
Does anyone have photos of cam lock fasteners (or dzus, or cloc, or mil-spec, or whatever) installed on an RV-4 firewall? The cheeks on the RV4 cowl make the mounting situation quite a bit different than the others.

Before I do it my own way and discover its flaws, I'd love to see someone else's installation and hear about its merits and disadvantages.

Thanks!

Matthew
 
Try some rubbing compound on the pins, with a drill

i.e. use a dab of rubbing compound (from local auto store) then chuck the straight pin into a drill,.. and run it in and out of the cowl a few times.

Due to problems with fitup and bending of hinge loops I changed and used a stainless steel hinge and pin,.. and it was a bit stiff at first.

but be careful and don't go overboard, (leave it a little stiff).... and make sure you clean up after you "fit" the hinge.

Also... make sure you do a "pre-fit" check and make sure hinges are not bent out of alignment and you do not have anything blocking them.
 
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