More Capacitor Work

Time: 7 Hours

Todays started with the finishing off the shaping of the 2 outboard capacitor plates to make for clearance the tank stiffeners on the bottom if the tank skin. Van’s says you can trim the plate and/or the stiffeners. I decided to just do the plates and measured for such.



20140126-131747.jpgSince the plates are exactly the same just on opposite tanks I just put them back to back to shape them at the same time.

20140126-131933.jpgJust a few minutes at the scotch-brite wheel and I had a matching pair.

20140126-132051.jpgThere will be 12 spacers on each plate, 4 per hole. These had dangling chad hanging off them from the manufacturing process. I debured them with a utility knife around the outside edge as well as the inner hole.

20140126-132602.jpgThe point of the spacers is to isolate the plate from the rib. You also use 1/4″ clear tubing that you slide over the screw to further ensure that there is no potential contact between the plate and the rib that it is screwed to. I made these tubes to the 15/32″ as per the plans.


20140126-132958.jpgThat’s as far as I can go on the fuel capacitor kit as I’m waiting for my wire stripper and crimper to arrive this week. So I moved on to the next steps in the plans. In the inboard ribs of bit tanks there is an access plate that allows for servicing to fuel pick up lines (my case the flop tubes). This plate is rather large and you need to cut that hole in the rib. I ordered my fly cutter from Cleaveland Aircraft Tool.

20140126-142831.jpgI did the measuring to get to the center of of the circle of the rib and moved it to the drill press.

20140126-143133.jpgThis cutter made quick work if the cut and I was able to knock out both ribs fairly quick.



20140126-143448.jpgEach rib gets a stiffener ring and an access hole cover plate. The original cover has various holes it if for the normal fuel pick-up line and the float type fuel sender. With the capacitor kit it is just a blank cover as you don’t need any of those holes.

20140126-143611.jpgNext up was to line up the stiffening ring so that the holes line up and allow the cover plates flat spot to sit parallel with the ribs stiffener bead.

20140126-153554.jpgThe. I was able to match drill all the #40 holes for the nutplates and the #19 holes for the AN509-8R8 screws that hold the cover plate on.


20140126-153819.jpgThe stiffener ring gets riveted to the rib and nutplate. The ring needs to have the rivet holes countersunk to accept the dimples from the rivet holes in the rib. That way the rivets will be flush with the inboard side if the rib to allow the access cover plate to sit flush and be sealed. I set up a piece of oak and drilled half of the rings holes into it and clecko’d it down. This gives my countersink bits pilot to have a guide in the wood and removed the chance of the bit wandering.

20140126-154259.jpgWith all the holes in the rib debured I hit the rivet holes with my 3/32″ dimple dies setup in the pneumatic squeezer (my favorite tool) and dimpled all the holes in a matter of 60 seconds.


20140126-155633.jpgLeft side done and on to the right side. I would probably have my plane done by now if I didn’t have A.O.C.D. (Advanced Obsessive Compulsive Disorder) as I have to clean up my work area after each project. So even though I will be drilling the right side now I needed to clean up before doing so. That means vacuuming all the drill shavings and mess I made.

20140126-170301.jpgBith sides are done but before I can do any riveting I need to debur all the edges. So I hit all the inside circles with a 1″ scotch-brite wheel and all the outside edges on the bench wheel. Then I clecko’d everything up and grabbed the squeezer. I had all of the nutplates riveted in about 30 minutes.



20140126-191037.jpgI then grabbed 12 of the AN518-8R8 screws and temporally attached the covers.

20140126-191505.jpgIt was a pretty good day in the Hangar! Next up will be the fuel drains and and fuel caps.

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