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Tip: Never, Ever, Ever Assume?.


VAF Moderator / Line Boy
So there I was, a nice pleasant evening, all by myself, fabricating a couple of fuel tank close-out plates for the RV-3 (Louise gave me permission to fabricate these in her absence, since in most of the sophisticated kits, they come pre-cut and punched, and I enjoy bringing parts from raw stock to ?kit? status). For some reason, we didn?t even get material for them with our QB wings, but a neighbor had a nice chunk of .063 to cut some 6? circles out of, and I was on my way. I used some translucent graph paper on the root ribs to transfer the location of the close-out nut plates from the tank to the plate, and marked the location for the fuel pick-up and the fuel level senders. Working on the left plate (because it was the one shown on the drawing) I cleverly used the fuel sender gasket to mark the location of the marking holes, because I remembered from my previous build that the holes are NOT evenly spaced ? they are spaced funny to prevent you from installing the sender upside down or sideways.

In production mode, I then moved to the right plate and marked the same things, flipping the gasket for the sending unit over to make sure it was going to be right side up.

[OK, stop here?see my assumption? I ASSUMED that the bolt hole pattern on the right sender was a mirror image of the left sender?.WRONG!! Not only do they drill the holes in an irregular pattern so that you can?t mount the sender the wrong way, they have SEPARATE patterns for the left and right senders?.]

Out came the drill in production mode, and sure enough, when the chips had flown and the holes produced, the right sender mounting holes wouldn?t line up in any orientation. Of course, this meant that I got to have the fun of starting over from scratch on the right plate ? fortunately, I had enough extra material to cut out one more 6? circle. And fortunately, I had nothing else to work on, so this gave me an excuse to spend another half hour in the shop ? quality time! ;)

Tip, Lesson, What-have-you?.Never assume that the Right and Left of ANYTHING are going to be mirror images. Many times, they will be, but just when you get on a roll?..Van?s will snap you back to reality!

There's a great poster that hangs in our club's towplane hangar shop. It's not safe for VAF, but it involves a woman in a tennis skirt outfit and in large letters, the word "CHECK"....

Reality hits you really hard sometimes.

I confess I was so naive when I started my RV-7 that I thought I would not have to drill out any rivets and that I would not have to re-make any parts. :eek:

Then reality bonked me on the noggin'!

Oh well, I have a special place for messed up aluminum parts. It's those red plastic Folger's coffee containers over there on the bottom shelf. There's always hope that some of them can be used to re-make parts I may mess up later.

Interesting, Paul. They're just trying to keep us on our toes.

But the left and right sensors do use the same gasket. So, those clever guys figured that you could flip the gasket over and create a different pattern.