Tip: Hidden Hinge Oil Door

If you mount the oil door on the cowling the way the plans show you, your door will work just fine. However, over time, you'll notice a black streak on your cowl from the hinge line streaking aft. I'm not sure of why the streak forms, but it does. So on my Rocket, I fabricated a hidden hinge on the door.

I bent some aluminum to make a hinge as shown. I also reinforced the hinge mounting area with about 10 plys of fiberglass. The idea is to allow the door to swing up and away and not hit the cowl until the hinge is stopped by the lip in the opening.

When you're done, it looks like this.

Another very nice tip from Randy...thanks

And here are some pictures of my very similar install.

Cowl install pictures

Latch Source??

Would you please provide the source of the latch? Also, is the door spring loaded in any way (doesn't appear to be) or is it loose flapping except when latched?

Hidden Latch

Here is your source for oil door hidden latch system!

This state of the art latch mechanism is made out of 6061 anodized aluminum with a stainless steel latch pin, pull cable with handle, and latch recepticle. Latch recepticle operates on a bevel to bevel sliding action, allowing automatic bolt lock when oil door is shut.

The Kit includes the 6061 anodized aluminum hinge a complex shape designed from extrusion. Thouough instructions include builders tips, and the much needed reinforcement designed out of carbon fiber, to prevent in-flight flexing of the oil door.


Pictures of hidden oil door latch system mounted on a RV 7.


(pictures won't download!)
Why?



Here is the link to more hidden oil door latch systems, mounted on different planes we have built.

http://www.advancedaviationinc.com

The Hidden Oil Door Latch kit is available through:
Aviax, Inc.
1661 N.E. Cackler Ln.
Bend, Or. 97701
Order though e-mail at: [email protected]

How to insert pictures:
http://www.vansairforce.net/articles/ImagesInForums/images.htm

Best,

Big Brother

You can always count on Doug to be looking over your shoulder.....

Hwood

Hidden oil door hinges

I believe the hinges shown in Andy's picture are the ones available from McMaster Carr, P/N 11205A35 - $3.60 each, 11205A36 - $7.45 each. P/N's are from Dan Checkoway's site! Used them on my -8, worked great!
Bill Waters

Cheap hidden oil door latch

Aviax said:

Here is your source for oil door hidden latch system! This state of the art latch mechanism........

Click to expand...

Nice, but no offense, $200 is a bit steep (that's Lancair money). There is an easier way to have a hidden latch. Use some spare piano hinge and wire. Lighter, cheaper (free if you have spare hinge) and looks great. (Stole idea from RV featured in EAA Sport Aviation). Cheers George

Aluminum versions of McMaster's concealed hinges

rvpilot said:

I believe the hinges shown in Andy's picture are the ones available from McMaster Carr, P/N 11205A35 - $3.60 each, 11205A36 - $7.45 each. P/N's are from Dan Checkoway's site! Used them on my -8, worked great!
Bill Waters

Click to expand...

Here's a message from Tom Sargent that appeared on the Matronics rv-list a couple of weeks ago. Thanks much to Tom for pointing out a great source for aluminum, not steel, hinge brackets equivalent to the steel ones I bought from McMaster. They're cheap, too!

FWIW, I found a concealed hinge that I believe will work well for an oil
door. It is like the hinges from McMaster-Carr that I have seen
referenced on the list before, except that it is made of aluminum
instead of steel.

http://www.guden.com/display-chh.asp

The Guden part number is NHAL9290. I think if it is positioned
properly, it should allow the door to swing open about 120 deg., so it
should stay propped open.
--
Tom Sargent
RV-6A, Cowling

Click to expand...

George:

Link does not work.

gmcjetpilot said:

Nice, but no offense, $200 is a bit steep (that's Lancair money). There is an easier way to have a hidden latch. Use some spare piano hinge and wire. Lighter, cheaper (free if you have spare hinge) and looks great. (Stole idea from RV featured in EAA Sport Aviation). Cheers George

(SEE LINK BELOW FOR $1.50 HIDDEN LATCH IDEA)

Click to expand...

piano hinge for me

I'm on my third iteration. That spot of different fiberglass on the top cowl that looks perfect for a pull hinge spot isn't. Baffling goes right there.

Gorilla glue didn't work too well holding my tube in place. etc etc. $200 versus two mos. hum. that's cheap, I knew a lancair guy probably had it figured out. along with the glassair III at OSH in 2003 on display.

Don't be fooled, other less expensive hinges are sloppy with too much play. Spring loaded hinge swings door open automatically after pulling release handle.

Here are some pictures of the hidden oil door latch kit installed on an RV-7 cowling. The kit comes assembled and ready to gule on with its included mounting hardware.











Thank you Doug for the photo link help!
Aaron Brook

After 4 hours and an oil door and cowl that looks like swiss cheese, now curing epoxy and flox, I can not get the hidden hinge to operate properly. Can all those who have made it work shed some light into this geometric puzzel? I have premade hinges from McMaster Carr...even went an fabricated one like Randy's F1 rocket...the door still binds or does not move up and out of the pocket...I tried moving the hinge line inwards...outwards...made the seat smaller...I know I'm missing that one little thing that will make this work..

another hidden hinge option

Here is another option for those who want to try a hidden hinge:

http://www.thervjournal.com/hidden_hinge.htm

Mine was a retro-fit but you could use this hinge for a slick new installation.

Similar to George's

Except my latch hinge pin is pulled out from behind the TU open canopy rail.

Its less of a reach and the closed canopy frame prevents the hinge pin from sliding out.

Frank