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Flop tube in QB tank

kens_cockpit

Well Known Member
I've got the QB everything including the QB tank. I would like to install a flop tube to allow relatively sustained inverted flight. I recall some Van's information when I ordered the kit that this wouldn't be possible with the QB. I was willing to accept that.

But I thought in the great world of RV builders there would be someone who has a fix for this. I had a look at the plans last night to figure it for myself (Ref Drawing 16A). I think I could put some blind rivets in to attach the anti-hang-up guides and the trap door. However I have the float type sender which needs to be moved to the second compartment which I cannot now access without pulling the tank apart which I don't find desirable!

I could just install the float type sender in the first compartment but it would be likely to get hooked up with the flop tube - also undersirable.

Could I use a capacitative type sender instead?

Are there any suggestions for doing this out there?
 
I just finished my first tank. I installed the flop tube with the sender in the second bay. The sending unit cannot be in the same bay as the flop tube, it will hit!!! To install the sending unit in the second bay required cutting a hole in the rear baffle at the inboard side of the second bay and installing nutplates to attach the sending unit. I really wouldn't want to do this after the tank was completed but I guess it is possible. The flop tube is installed by drilling a hole in the nose stiffener / angle bracket. More doable than the sending unit but still very difficult. The capacitance senders need to be attached to the ribs..again difficult if not impossible....personally I would rather put the float in the second bay. If you are insistent on having a flop tube, then you may think about ordering the materials and building one tank with the flop tube. Lots of extra work but I would think it is easier than cutting all those holes in your rear baffle and working through the inboard access hole.

good luck

Jim Kinsey
7A wings
 
Actually what Jim says about installing the float in the second bay is not that difficult. Many of us "older" builders had to cut service panels in every bay of the baffle to remove the old "slosh compound". Just cut a hole in the second bay of the baffle, install the float in the cover plate, and reinstall. It will take a little bit of work to get the float travel adjusted, but it's very doable.
Mel...DAR
 
I installed a flop tube in the left tank of my 4 a month after the tank was built. It was no big deal at all. Any minute now people are going to post stuff telling you that you don't need a flop tube. But the truth is if you think there is ANY chance that you'll want to do a cuban 8, slow roll, etc. now is the time to install it.

Steve Zicree
 
I just knew there would be people out there who had done it. I'll give it a shot now. Mickey your pictures and description are very helpful. Thanks. I will be doing slow rolls and Cuban 8's so if I can pull this off I'll be wrapped!
 
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