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Battery access door

bluebonnet

I'm New Here
I'm a new member building an RV8-A. I'll probably have a lot of questions.
Question- I have seen various mods to access the aft mounted battery through
the baggage area. Has anybody cut an access door in the aft side skin. What
are the pros and cons? Structural- etc. Thanks for any help and opinions,
 
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Welcome to VAF

I'm a new member building an RV8-A. I'll probably have a lot of questions.

Fred, welcome aboard the good ship VAF.

Methinks you need to get the factory to answer the question about cutting a hole in the side skin.
 
I got this from someone else on VAF - happy I made it. I would never consider cutting a hole in the skin.

Carl

2700-A211-C218-42-A8-9-D6-C-CBA484-DA6039.jpg
 
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Do not cut a hole in the side skin.

It would be all but useless anyway. You will remove the baggage compartment shelf and rear bulkhead at least once a year for a decent inspection. A quick access panel in the baggage shelf works fine for minor stuff.
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Holes are heavy.

Holes are light, there's nothing there. It's ensuring the hole retains the required structural strength that's heavy. Similar to how a fall never hurt anyone, the sudden stop at the end is what gets you. :cool:
 
Yup

Holes are light, there's nothing there. It's ensuring the hole retains the required structural strength that's heavy. Similar to how a fall never hurt anyone, the sudden stop at the end is what gets you. :cool:

:) Same argument, couched a bit differently. I’m a wannabe engineer, at least my business card at the last place I worked said I was an engineer. Not bad for a guy with an HSG degree. But the real engineers I worked with all said holes are heavy, shorthand for just what David said.... keeping structural integrity around said holes adds weight. For example, a hole in a semimonocoque fuselage, big enough to access a battery, is going to add significant weight if it’s reinforced enough to maintain the same strength and stiffness. The door and it’s attaching hardware will be heavier than just a simple sheet of .025, too. The wording “Holes are heavy” is very elegant, no?
 
How often ???

Not flying yet...
How often do you need to check the battery???
It's a dozen or so screws that hold the upper bagage floor and the rear bulkhead... 120 seconds to remove...

My 2 cents... :cool:
 
Not worth the effort

Not flying yet...
How often do you need to check the battery???
It's a dozen or so screws that hold the upper baggage floor and the rear bulkhead... 120 seconds to remove...

I added a hatch to the baggage floor and if building again, I would NOT spend the time and effort for this mod. For inspections and battery maintenance, I still have to remove the baggage floor. The hatch may be great to look in and see that everything is where is should be, but rather useless when it comes to maintenance issues. It took me about 15 hours to design and construct the hatch--wish I had skipped this mod.
 
Not flying yet...
How often do you need to check the battery???
It's a dozen or so screws that hold the upper bagage floor and the rear bulkhead... 120 seconds to remove...

My 2 cents... :cool:

ask someone maintaining an 8 about getting those screws out, and that big piece of bent aluminum around you and out while kneeling in the back cave. (without bending or scratching anything)

You'll put a quick access hatch in the second 8 you build....
 
ask someone maintaining an 8 about getting those screws out, and that big piece of bent aluminum around you and out while kneeling in the back cave. (without bending or scratching anything)

You'll put a quick access hatch in the second 8 you build....

Exactly!

My first RV-8A does not have the access door that I posted. The new RV-8 does. The access door is big enough to replace the battery, get to the bell crank and AP servo. Just finished the first Condition Inspection on the new RV-8 and it was a joy not to loose my religion with butt up, head down trying to get the screws to line up.

Carl
 
We'll see...

ask someone maintaining an 8 about getting those screws out, and that big piece of bent aluminum around you and out while kneeling in the back cave. (without bending or scratching anything)

You'll put a quick access hatch in the second 8 you build....

Exactly!

My first RV-8A does not have the access door that I posted. The new RV-8 does. The access door is big enough to replace the battery, get to the bell crank and AP servo. Just finished the first Condition Inspection on the new RV-8 and it was a joy not to loose my religion with butt up, head down trying to get the screws to line up.

Carl


Mike & Carl,
I get your point that head down and butt facing the ceiling is not a glorious position to be in...:rolleyes:
When I work in there, (and I just spent a ton of time doing so installing the Battery with its vents, ADAHRS, ADSB, GPS, Transponder, Transmitter and ELT)... I raise the tail on a bench so fuselage is almost level. It really helps in maintaining some dignity while working in there!!!:D

I'll see with time if I say too many unpublisable words outloud when maintenance comes around.
 
Totally agree on raising the tail - much easier to work back there when it's level and all the blood is not flowing to your head.

To get the baggage area out to inspect the belcrank and autopilot servo I use Torx screws and a very long extension on my electric screwdriver - that way I can remove the screws while standing on the floor by just leaning over - very little Yoga involved. The beauty of Torx is that the bit stays in the screw, and they don't strip like a Phillips.

I also put a very small EarthX on the firewall to avoid having to inspect the battery back there - saves weight and very easy to access via the oil door or removing the cowling. Very happy with that decision.
 
ask someone maintaining an 8 about getting those screws out, and that big piece of bent aluminum around you and out while kneeling in the back cave. (without bending or scratching anything)

You'll put a quick access hatch in the second 8 you build....

You can ask me. I've done it many times and not just for inspections.

It's one of the worst tasks there is in an -8, in my opinion. You are kneeling, bent over, but you have to also lean forward so you are either holding up your torso with stomach muscles or working one handed.

I'd rather slide up under the panel. And I don't like that either.

I wonder if replacing all the side screws of the lower panel with hinges and piano wire is as structurally sound as using the screws. Probable would have to keep the three screws along the back that also go through the back panel.

I like the idea of the Torx screws and drill bit extension. Going to look into that. Not sure how that helps on the horizontal surface screws, but for the others it may save a lot of pain and effort.
 
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Torx

Torx screws instead of Philipps...
I may have said it already elsewhere, but I like the idea.
Less chances of stripping over time.
 
I have an 18 inch flexible extension that takes screwdriver bits and I use it for most screw tasks with Wera bits that fit right. Keeps the drill out of the corners.

Reading with interest wonder if I should make a door too. If not with hinges then maybe just a doubler with a smaller screwed in panel that is easier than the whole shelf assembly.

Unclear to me how to decide how big I would need it to be useful.
 
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I made one big enough to easily get to the battery. Then I moved the battery to the firewall. It’s a nice opening in case I need to get back there outside the condition inspection. It’s held closed by 6 #8 screws.

 
Access Door with hartwell latch

While I don't have my battery in the back this is very useful for inspections.
IMG_3065.jpg
 
Another access door. Done after paint. Pigtail is for battery charging.
 

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Another access door. Done after paint. Pigtail is for battery charging.

That is a really nice installation. I think I'll put that installation idea on my project list
assuming that it is structurally sound.
 
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Plenty Strong

Doubler supports the 'door' and doubles as the latch catch. Obviously this is on the underside when assembled.
IMG_3063.jpg
 
No, but a battery charger door, yes

My 8 doesn't have an access panel for the battery, and yes the cuss words have flowed when it's time to inspect the battery. The suggestion of a long flexible drill extension and Torx screws will be implemented next year, thanks!

However, I do have a little 3" diameter hinged door in the belly under the battery. Inside that is a power plug - the one with the two big prongs in an oval shaft. Also inside is the little cable connector for a BatteryMinder, which I use to keep the battery charged. I really like this mod.
 
Ex172 - do you have pics?

Has anyone built a way to charge/jump a battery without climbing through the back seat? I know Bob Nuckolls suggests this in his book. Not something you'd use a lot, but it would certainly eliminate a lot of hassle if you needed it.
 
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