Tip: Oil Door with no Outside latch

[grantcarruthers]

Looks way cool!

Any reason not to place the hinge at the forward/leading edge? This way if you forget to latch or if latch fails in flight the slip stream will hold it mostly closed or at least not rip it off?? Cable run would have to do a 180 instead of 90 degree turn but other than that???

[mburch]

Originally Posted by grantcarruthers

Any reason not to place the hinge at the forward/leading edge? This way if you forget to latch or if latch fails in flight the slip stream will hold it mostly closed or at least not rip it off??

The forward and aft edges of the oil door are curved, so hard to affix a hinge to. Only the edges parallel to the longitudinal axis of the airplane are straight. Also, I think the hinge the thread author is using is spring-loaded, thus hard to miss during preflight.

I have had an oil door pop open in flight on an RV... it just bobs there serenely until you reduce speed and land. Not a big deal, at least in my experience.

mcb

[RV7Guy]

Very nice set up. It actually looks like less work than getting a couple of Hartwell latches to fit properly.

I also thought of using a trim servo with a hidden switch to operate. Actually I think a high torque Radio Control servo would be more than adequate.

[Stevejohnson7@gmail.com]

THANKS for the nice compliments! I will attempt to answer the questions asked:
1. Yes, some Lancair builders use this latch system and I bought it at www.advancedaviationinc.com/v2/site.html for around $225; however, I modified it slightly for a RV. I think you could get reasonably close for less $ if you spent the TIME to piece it together. Keep in mind there are more than a couple pieces. There are:
1. The hinge WITH the cable internally attached to it.
2. A built-up fiberglass mounting plate for the hinge.
3. The clasp that the hinge pin fits nicely and firmly into.
4. A built-up fiberglass mounting plate for the clasp.
5. The long cable designed to be cut down with a tough plastic liner.
6. A small fitting to make a pull loop that fits your finger.
7. And the little tubing that fits the finger loop.

I do not know where you would find #s 1, 2 & 4.

COUPLE OF IDEAS:
1. I roughed up the fiberglass with #30 sand papper and hot glued the tube in place. WORKS REALLY WELL.
2. Due to the extreme air pressure in the upper cowl, you have to stiffin up the 1/8" thick fiberglass door. I choose to add 3/8" ridgid foam with 45 degree edges on the back of the door and applied a couple layers of very strong carbon fiber material.
3. I placed the finger pull on the Pilot side because the front left cylinder head is way back on the Pilot side and your won't burn your hand when you reach in to pull the latch.

OH, and regarding pics of my paint I will put post some when paint job is 100% complete. I did post a few pics titled: "New Tail Art".

THANKS ALOT! HAPPY BUILDING........

[Stevejohnson7@gmail.com]

Hey Bugsy I did post a few pictures. See: http://www.vansairforce.com/communit...ad.php?t=29886 I will post the full plane paint job when 100% complete. THANKS!

[szicree]

Originally Posted by Stevejohnson7@gmail.com

2. Due to the extreme air pressure in the upper cowl, you have to stiffin up the 1/8" thick fiberglass door.

On my -4 the oil door is aft of the rear baffle, so I'm hoping that pressure is not going to be an issue. Am I correct on this?

[Stevejohnson7@gmail.com]

Still need to reinforce. 7 and 4 oil doors are both aft of baffle. Air is rammed in two front holes in cowl and down across cylinder fins to cool engine and out bottom back of cowl. Still alot of upward pressure in top back of cowl. Its baffling. FYI....pic of sanding cowl with 30 grit and hot glueing down cable.

[Tom Martin]

Steve
The air aft of the plenum is still under pressure relative to the outside air. In my top plenum I have about 12" of water pressure and aft of the plenum there is about 7". Stiffeners to the door can always be added after first flight, if you feel they are needed.

[ScottSchmidt]

You don't need to spend that type of money.
I bought this latch from Aircraft Spruce, then took out the center slide and machined the inside of the slide and placed a set screw in it to pinch the cable that I bought at Lowes in the aviation department. I then put a hole in the outside of the latch for the wire to run through and it worked great.
The latch was only about $25 when I bought it. It is now $33 I think.
I was probably into my system around $40.

I then glassed in the tube with the wire in the middle. I need to redo my latch on the door someday and make it stiffer, but it works great.

Now, if I were to do it again I would probably just do the flush latches that most people use. They are easy and work great. But is is always fun to mess around with cool stuff like flush mounted oil doors.

http://www.aircraftspruce.com/catalo...univsprlat.php

[Stevejohnson7@gmail.com]

Scott, You have me confused now. You wrote: "If I were to do it again I would probably just do the flush latches that most people use". Can you please explain to me the reasons why you would do the above?.