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Cessna KM610-64 Oil Door Latch and Hinge

rockitdoc

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I know a lot of builders have done this conversion. I am about finished with my conversion (see mockup with Cessna door attached for adjustment of the aluminum reinforced latch catch on the cowl), but am wondering if two latches might be wise. I found a thread where somebody used two latches, but can't find the thread again to ask. Overkill? Anybody do this conversion and use one catch in the center like on the C172?
Thanks, in advance, as usual.
Scott
 
Oil Door Conversion Photos continued

One more from below showing the hinge spring and reinforced fiberglass at catch.
Oil Door Below2.jpg
 
Latch - Oil Door

I have two cessna latches on my RV9. 9 years and 600 hours later and it still works great. Will be putting two latches on the 14 under construction.
 
I have two cessna latches on my RV9. 9 years and 600 hours later and it still works great. Will be putting two latches on the 14 under construction.

Thanks Jim. I guess since you are doing the same on your -14, you think two is not overkill?
 
That looks nice. I also like the RV14 oil door hinge. That’s what I’m putting on my RV6 (build).
I decided against the Van's hinge only because it lacks a spring. The spring is nice for keeping the door open while checking oil. It also pops the door up a bit after pushing the release button.
 
The Cessna door looks like it may be harder to install the cowl pins. Do you plan on doing Camlocks? I find the standard door is just big enough to work the cowl pins in.
 
The Cessna door looks like it may be harder to install the cowl pins. Do you plan on doing Camlocks? I find the standard door is just big enough to work the cowl pins in.

That photo with the Cessna door is just a mockup to get the latch configured. The door will be the original Van's door.
 
I only have single latch...works good if you have metal catch thats a little thinner to engage the latch face a bit more and the oil door is stiffened to prevent flexing

I fabricated a strip of 0.016" AL into a U-shape to surround the fiberglass 'shelf' where the AL oil door will reside. After shaving the fiberglass to 0.030", the aluminum surround brings the overall thickness of the 'shelf' to 0.060" which fits nicely in the KM610-64 latch. The AL 'armor' surrounding the shelf should provide a more substantial, and hopefully, more durable bearing surface for the latch.

I think I will use two latches, though. Mainly cuz I already ordered the second one, and because the weight is negligible and provides redundant latching power.

More pix to come.
 
I decided against the Van's hinge only because it lacks a spring. The spring is nice for keeping the door open while checking oil. It also pops the door up a bit after pushing the release button.

The RV14 oil doors I’ve seen don’t need a spring. It just stays open, but probably not on a windy day, depending on wind direction. I made a simple stay open mod on my RV4 with a hinge eye and a short piece of bent hinge pin. It was very simple and worked perfectly for keeping the oil door open when needed.
 
What I Settled On

One latch will do the trick. Another builder has used a single Cessna latch for many hours with no issues. Simple.

I had to make my spring in the hinge 'springier' by adding a bit of angle to give the spring something to bear on when open. I also added some 0.060" to the hinge to move the attach rivets further from the opening (probably not necessary, in hind sight)

Next step will be to smooth out the cowl with epoxy and flock to match the door exactly.

Oil Door w:Button.jpg

Oil Door Latch Below.jpg

Oil Door Hinge Below.jpg
 
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Bodywork to Complete Oil Door

It took three epoxy applications, but I THINK the door will be nice and even with the surrounding fiberglass cowling.

This is the first sanding of the first epoxy coating. Notice low spots that still need filling. I thought I had applied enough. Oh, well...

Oil Door First Sanding.jpg

This is the second epoxy coating

Oil Door Second Epoxy Coating.jpg

I just applied the third coat which SHOULD be enough to get all the low spots and make the aluminum door match the surrounding glass. It is surprising how uneven the fiberglass is, but the epoxy finds every low spot. Lots of sanding and re-sanding should make this turn out pretty smooth. Primer-surfacer will go on next with more sanding and re-sanding before paint.
 
Scott, given all the effort you've put into this, consider reinforcing the door panel itself. An aluminum panel door with no rib(s) will surely bow outward due to internal cowl pressure. The result is two kinds of drag.
 
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Am I Clueless?

So can someone list the part number for the hinge?
I see the latch part number is in a previous post.
 
Scott, given all the effort you've put into this, consider reinforcing the door panel itself. An aluminum panel door with no rib(s) will surely bow outward due to internal cowl pressure. The result is two kinds of drag.

I wondered about that, hence the thought about two latches. And, I think reinforcing it makes sense.
 
Scott, given all the effort you've put into this, consider reinforcing the door panel itself. An aluminum panel door with no rib(s) will surely bow outward due to internal cowl pressure. The result is two kinds of drag.

An .063 thick aluminum door like supplied in the kit for the RV-14, is stiff enough to hold its shape (though not quite as light as a properly stiffened composite door).
 
An .063 thick aluminum door like supplied in the kit for the RV-14, is stiff enough to hold its shape (though not quite as light as a properly stiffened composite door).

That is what I used. I couldn’t use the kit supplied door, because it had holes in the wrong place, but a new one was easy to make from stock. I used 2 latches and a spring hinge.
 

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An .063 thick aluminum door like supplied in the kit for the RV-14, is stiff enough to hold its shape (though not quite as light as a properly stiffened composite door).

Scott,
After looking at the curved shape of the door in the places where it would flex I came to the same conclusion. The curvature increases the already stiff 0.063” AL. Reinforcement is overkill and just adds weight.
S
 
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An .063 thick aluminum door like supplied in the kit for the RV-14, is stiff enough to hold its shape (though not quite as light as a properly stiffened composite door).

I maybe should qualify the above by saying "when installed using two camlock fasteners as detailed in the kit".

Using other types of latches that just hold the door closed (but don't restrain the position of the door like camlocks do) might allow the door to pillow slight from internal pressure.
 
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