Sunday, June 21, 2015

Instillation Of Fuel Tank Venting System Begins

Have I mentioned I’ve been on a hole drilling kick as of late?  While the step drill is still chucked up in the drill, decided to pop the hole into the F-1207C-R baggage bulkhead for the fuel tank vent.  Van’s new drawings for the fuel tank show where to drill the hole for the fuel tank vent … however, the DOG Aviation procurement department has already taken possession of the baggage bulkhead covering offered by Abby at Flightline Interiors. Decided the wisest thing to do was to bring the bulkhead cover to the hangar and use it as the template for the hole location.
Using the slot Abby at Flightline Interiors cut into the bulkhead cover as a locater for the positioning of the fuel tank vent. While the cover was in place a scrap piece of tubing was used to determine hole placement.

After marking the hole, it was drilled to 1/2" and a snap bushing was installed per the plans.
The fuel tank vent hole is now drilled through the F-1207C-R baggage bulkhead and snap bushing in place. A scrap piece of tubing was inserted to aid in positioning the “T” behind the baggage bulkhead and for further measurements for the vent line.

While bending the aluminum tubing it was discovered the DOG Aviation tubing bender does not make bends quite as tight as the bends shown in Van’s drawings. Therefore the exact footprint on the plans can’t be duplicated. As such, had to wing it and have now got the aluminum vent line fairly close to being usable but it still requires a little tweaking.
The Van’s drawing is supposed to be 1:1 and as can be seen ... the big bend in the tubing is not tight enough.

To make up for the relaxed bend, the mounting bracket the Adel clamp will mount onto was flipped around and now the vent tubing is fairly close but still in need of some adjustments.
Initial trial fitting of the upper portion of the vent tubing … getting close, but there is more work to do to refine the positioning of the tubing.
Bottom portion of tubing will need to be drawn over a little so the Adel clamp that will be mounted onto the painted bracket can capture it.

I’m hoping to be able to tweak the vent line I have going … but if it does not cooperate during the next work session will just remake it now that I have a better understanding of how it needs to be routed.