R

rv8_builder

Active Member
I am preparing for my work session at the hanger this weekend and was wondering where you guys got the hinge for the fuel tank trap door :confused:

Is there a hinge in the wing or fuselage kit that is long enough to cut a piece from or do I have to order from Van's?

I am only installing a flop tube in the left tank so I only need one.

Andre Burger
South Africa
RV-8 Tanks
 
Andre,

You fabricate it from a small bit of MS20257-3 hinge stock that should be included with your wing kit.

 
Thanks for the quick reply Rick.:)

I'll look for it in the wing kit this weekend.

Andre Burger
South Africa
RV-8 Tanks
 
What tank trap door hinge?

Rick6a said:
Andre,

You fabricate it from a small bit of MS20257-3 hinge stock that should be included with your wing kit.

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Rick, exactly what is this door for? :confused: I hate to sound stupid which comes easy for me but this is the first time I have ever heard of it. I'm re-starting that stage of construction now and I don't want to miss anything.
 
NYTOM said:
Rick, exactly what is this door for? :confused: I hate to sound stupid which comes easy for me but this is the first time I have ever heard of it. I'm re-starting that stage of construction now and I don't want to miss anything.
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Tom,

Somebody here can probably give you a better answer, but I think the door acts as a sort of restrictor so when in manuevering flight, fuel contained within the inboard bay of the fuel tank cannot flow outboard as quickly as it otherwise would.
 
Thanks Rick

I get it now. Kind of a check valve in the baffle to keep the pick up tube wet.
Pretty good idea. Is that mod very common or is it just done by the guys who don't like to fly straight & level?
 
The part that I don't understand about this mod is that the hole on the center of the rib is left open per the plans. I covered the hole. Both tanks have the mod even though only one tank has the flop tube.

FP24062007A000DV.jpg

FP24062007A000DG.jpg

FP24062007A000DK.jpg
 
NYTOM said:
I get it now. Kind of a check valve in the baffle to keep the pick up tube wet.
Pretty good idea. Is that mod very common or is it just done by the guys who don't like to fly straight & level?
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That's a good question for a poll. I have a flop installed in my -6A and installed one trap door per plans. I have no flop installed in the current project yet installed a trap in both tanks just because I was in the neigborhood and was easy to do at that moment of time in construction. I figure IF I ever decide to add a flop, however unlikely that is, the trap door mod (in the fuel tank of choice) would be one less PITA to deal with. My reasoning may be questioned but what the heck, what's done is done. The whole deal with a flop tube is overrated anyway. You only need it for sustained inverted flight (which would also require an expensive oil system) and other negative maneuvers.
 
AX-O said:
The part that I don't understand about this mod is that the hole on the center of the rib is left open per the plans. I covered the hole. Both tanks have the mod even though only one tank has the flop tube.
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Your not trying to keep all the fuel from draining out (your not going to be manuvering that long) just the fuel at the bottom of the tank where the pick-up normally is. If your doing negative G's, the fuel will be at the top and there's no large hole there.

Karl
 
Here she is !

I made the trap door yesterday and it came out OK.

Thanks for the help :)

DSC01243.JPG


Andre Burger
South Africa
RV-8 Tanks
 
Reprise of an old question.

The original question in this post was where is the hinge material for the trap door came from. I'm at that point today. The kit has two 6 foot piano hinges and an 18 inch section AN257-P2X18 HINGE X 18" The question is, do you use this 18 inch section of the piano hinge to cut the hinges for the fuel tank trap doors? Interesting enough, the 18 inch section is not on my parts list.
 
Caummisar said:
The original question in this post was where is the hinge material for the trap door came from. I'm at that point today. The kit has two 6 foot piano hinges and an 18 inch section AN257-P2X18 HINGE X 18" The question is, do you use this 18 inch section of the piano hinge to cut the hinges for the fuel tank trap doors? Interesting enough, the 18 inch section is not on my parts list.
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The trap door is optional, just like the flop tube. When you order the flop tube, order 1 ft of hinge material.

Karl
 
take some from the stock provided for the flaps

the flaps have, as I recall, about an extra foot each remaining after you build them.

go to town using some of this extra stock.
 
fuel tank baffle

A detail I see left out in the pictures in this thread is to leave the hinge pin long and bend the ends such that the "flapper" cannot open past about 45 degrees - certainly not past 90 degrees. If you don't provide a way to liimit the travel of the "flapper" it can swing all the way up and not perform its intended function of acting as a check-valve.
 
Stopper

larryj said:
A detail I see left out in the pictures in this thread is to leave the hinge pin long and bend the ends such that the "flapper" cannot open past about 45 degrees - certainly not past 90 degrees. If you don't provide a way to liimit the travel of the "flapper" it can swing all the way up and not perform its intended function of acting as a check-valve.
Click to expand...

Larry,

If you look closely at the pictures you'll see that the end of the hinge is bent up 90 degrees to provide a stopper :)
 
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