Completed the left fuel vent line - 3 hours

Well it took some work but I managed to complete the left fuel vent line. I was able to use all of the templates that I made previously as a guide. 

Even more fuel vent work - 6 hours

 Following the same method as before. I want to use smaller lengths of tubing to find the recipe and provide a template for the rest of the bends. It took some time to get it all worked out, but I'm pleased with the results. I will now be able to use these to make the permanent fuel vent.

More fuel vent work - 1 hour

 Just a small day today on the fuel lines. I used a long section of tubing and started the bends on my actual fuel vent line. Managed to get all of the initial bends right and was able to attached the vent line to the bulkhead with the adel clamps.

Began the fuel vent install - 6 hours

 This is a part of the build that I was never really looking forward to. From what I've been reading this isn't the most simple and straight forward process. Then again, what did I expect....were building an AIRPLANE!

I have been looking at the option of F1 rocket style fuel vents that are coiled tubing contained within the wing root. Lots seem to report they work well. However I met an F1 Rocket owner and he didn't seem all that enthused about how they perform when I asked him about them. I ultimately decided to face the tricky tube bending head on. 

1/4" tubing is way more easy to work with and tweek versus the 3/8" tubing. So straight off I knew this would be less challenging then I thought. I decided that I will work the tubes from aft forward. Starting with the most difficult bends first and then leave the most simple and straight forward bends at the end.

Rather than eat up long lengths of tube, I choose to fabricate each bend making a template out of small sections of tube. This would allow me to "stitch" together a complete fuel vent with a precise example to follow.  I should note that all bends are been done with a tube bending tool, and only slight tweeks are being performed by hand. I also use a 1/4" tubing straighter to get all the coiled tubes straight before I start the bends. Both tools are fantastic and easy to use.

The first challenge is to sort the first section which turns out to be the most complicated portion of the vent. My first attempt clearly shows that I have distance issues between the 90deg fitting and the side stiffener angle.

The tube makes contact with the angle. So to solve this...I need to shorten the distance between the flair and the bend. Learning from previous samples I have shaved down the AN fitting sleeve. The result is that I can move the sleeve out of the way and get a much tighter distance between flair and bend. 

The result is excellent. Great spacing to go up and over that angle.

That solved, the next hurdle is to get the tube bent under the rudder cable. Simple enough... Using a piece of hinge pin strung through the rudder cable holes and attached to the rudder pedal with tape, I can easily see clearances.

At this point things look really good, but now I need to get this tube to offset enough so that it sits closer to the F-902 bulkhead and can attach with an adel clamp. That part of the bend is a pain. With my current setup, getting that offset bend is difficult and takes up a lot of space. It also looks awful. So, the way to fix that is to start my offset bends further down as the tube slips under the rudder cable. The result, while still tricky is a much more clean bend.

This is the exact 'recipe' for this section of bends (Keep in mind, that these work with my particular brands of tools);

1. Start the tube by bending 45deg a couple of inches from the end.

2. Flip the tube 180deg and then bend the tube 90deg immediately.

3. Measure 1" (Measured from the end of the previous bend to the start of the next bend).

4. Make a 45deg bend. (At this point you are now slipped under the rudder cable and the tube is pointing straight up from the fuel vent fitting).

5. Rotate the assembly 45deg in the tubing bender and bend the tube 60deg. (This now angles the tubing toward the bulkhead).

6. Measure 1" and then bend 60deg. (At this point the tubing should now be straight up to follow the F-902 bulkhead as shown in the picture above.)

7. At the end you have started on. The tubing can be cut and flaired. The exact length is 3/4” from end of the bend to the end of the tube.

8. Some slight tweeks will be required to get it all straight and aligned.




 

Began installing the fuel pump - 3.5 hours

 I had a visitor today (Jake) that was curious about the RV7 build. He wanted to see what the build was all about. We had a choice between starting the install of the fuel pump or fabricating the fuel vent lines. He opted for the fuel pump install, so we got right to it. 

We worked out the placement of the pump on the center cabin cover. Looks like the pump will be left of center, however it will clear the left side of the future doghouse panel. Once we were happy with the placement. We started working out templates out of paper to take the require measurements. We split the duties into two; 1 - the cabin cover cutout, 2 - the fuel selector cutout. I took care of the first, while Jake worked on the cutout on the fuel selector.

For my task, I need to remove material from the center cabin cover to fit around the Aerolab Filter/Gascolator. With the filter installed, working out the opening required in the center cover is easily determined. I made use of the hole saw used on the filter/gascolator install and then finished the process with a combination of dremel tools, files, and sanding drums. I'm very please with the fit. I made sure to leave a gap between the two to prevent rubbing and to help with some airflow.

 Jake transcribed his paper template onto a piece of 0.016" scrap aluminum. Once he got the feel for drilling, cutting and finishing the aluminum. He applied the final template to the actual fuel selector cover. Repeated the process of cutting and shaping the aluminum and the result is excellent. He certainly has the talent to build an RV. We fitted the assembly and we made a relief for the fuel line on the left side. 

 

All in all it was a fantastic and productive build session. Thank you Jake for your help.

 

Installing the F-782C center cabin cover - 4 hours

 I am now ready to fit the F-782C center cabin cover. This is not a quick process as there isn't great information on the drawings of where exactly to place the cabin cover. Its a bit of guesswork where it fits front to back. Height is 15/16" to the top of the cover...but getting that height set requires a recipe of wood shims.

It takes some time to get everything placed correctly. Once I have the wood shims putting the center cover at the correct height, I can now figure out the correct front-to-back placement. Everything will be predicated off of the F-983C fuel valve cover. 

I could move the center cover back and forth until the joint with the Fuel Valve cover sits nice and straight...no bow.

Now that I have the front-to-back placement of the cover figured out. I can now start setting the location of the screw mounting holes in the floor angles

I used a piece of scrap angle with the #19 hole (for a #8 screw) at the correct height. Using that drilling template... I then drill all 4 holes in the floor angles. Using the 90deg pneumatic drill for this is a life-saver. 

Once the holes are drilled, I placed the center cover and used a sharpie to check the hole placement in the sides of the cover. Looks ok. 

I re-installed the cover. Double checked for proper height and alignment and then drilled the 4 holes for the future #8 screws. 

 

Finished the filter/gascolator doubler - 1.5 hours

 Accessibility to dimple the doubler is difficult. I decided that I was going to use the rivet gun and a scrap chunk of steel to make the #6 screw dimples. I had ordered a chunk of steel from Metals Supermarket and will use that as a die holder/bucking bar. I had to clean up the steel and drill a hole to accept the female dimple die.

This setup is now used on the top side of the floor to allow use the male die in the rivet gun from below.

 Once all of the #6 holes where dimpled. I then used the pop-rivet dimpler to finish all of the remaining 3/32" holes.