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Current Limiter Installed and Misc. Tasks – 5 hrs

November 4, 2012 Leave a comment

Sunday, Oct 4, 2012

On Saturday the weather was warm, humidity was low and I had a few parts in the “to paint” pile so I fired up the paint gun. I primed the cabin air vent brackets, the firewall doubler for the current limiter and shunt, and the custom bracket I made for routing air lines in the aft fuselage. I also painted the doubler and air vent parts with JetFlex to match the rest of the interior. The doubler is not shown in this picture.

Here is the primed and painted doubler installed on the inside of the firewall (the one on the right).

And here is the ANL current limiter and shunt installed on the engine side of the firewall.

I also did some work routing wires from the ADAHRS to the forward cabin. I bought a bag of zip tie bases from McMaster-Carr. The nice thing about these tie bases is I can mount each one with one pop rivet. I installed four on the aft side of the vertical rib next to the bellcrank and routed the wires straight down to about 10 inches above the bottom skin. I put one more on the side of the vertical rib so I could route the wires away from the bellcrank. I also wrapped the wires with a piece of spiral wrap to protect it from scuffing. Pay not attention to that rats nest of air lines.

So next I cleaned up the air line routing using the custom bracket I made to guide the lines away from the bellcrank. This looks much better now. I will use pop rivets to secure that bracket once I feel confident I am done climbing back in there.

The air lines route through a piece of plastic conduit to right below the pilot’s seat. From there I drilled four holes and installed snap bushings to route the blue (AOA) and green (pitot) lines out this side of the fuselage to the left wing. The green line has a T in teh outboard bay so I can route a branch forward to the backup instrument which will probably be a TruTrak Gemini PFD. That white tube you see in this picture is just a placeholder piece of scrap I had on hand. It will be replaced later by a green piece to the wing air connector.

The F-782 tunnel cover is an awkward part with a fuel injection boost pump installed. I’ve never liked the fact that you have to pull out the fuel pump and fuel line out to get access to the wiring in the front section. So I decided to cut the F-782 in half. The new aft section holds the fuel pump. Now I can install the pump and fuel line permanently and still have access in the front for wiring runs. It will also be better for maintenance and inspection purposes in the future. In this photo you can see the new cut line just to the right of the fuel pump. I will install two more nut plates so there will be four for each section to mount these to the floor ribs.

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Installed Relay Diodes – 1 hr

July 18, 2012 Leave a comment

Wednesday July 18, 2012

All I did tonight is install the diodes on the relays and put a small piece of shrink sleeving on the copper bars that tie them together. I really like the fact that the diode jumpers come pre-made in the Vans firewall forward kit. That saves a bunch of time.

Finished Mounting Relays – 2 hrs

July 15, 2012 Leave a comment

Sunday July 15, 2012

This morning I riveted the contactor doubler and nut plates to the firewall. That is the hole pattern between the two contactors.

Here is how it looks from the inside (behind the rudder pedal).

The two contactors are electrically connected by a pair of .062 thick copper bars that I had to order separately from Vans. I wanted to make sure I got the length right so I made an aluminum template first. That gave me confidence to cut the copper bar and drill holes for the terminals.

By the way I also made the clamping bar that holds the battery in the box with the two 7/8 inch spacers. Here is how this all looks mounted to the firewall.

Started Firewall Forward – 6 hrs

July 14, 2012 Leave a comment

Saturday July 14, 2012

My original plan was to install the latch lugs today for the canopy however, it occurred to me that I should install the weather seals along the sides before doing that so I can get the preload on the latches set correctly. Without the seals I run the risk of setting the latch lugs either too loose or too tight. The plans say “You should be able to feel the latch engage the lug when you work the latch handle, but you should not have to force the handle closed.” I ordered seal material from McMaster Carr last week and it’s not here yet so I decided to work on the firewall forward kit today and put a pause on the canopy.

The first step is to mount the hot air control valve on the firewall. Like most people I bought the stainless steel flapper valve from Avery instead of the aluminum valve from Vans. It requires a 2-inch diameter hole in the firewall. I measured the required distance from the firewall rivet lines and marked it for drilling. My 2-inch hole saw was worn so I ran over to Home Depot and bought a new bi-metal saw. It worked pretty hard to cut through the firewall but did so successfully as you can see below. I also drilled two holes for the mounting screws but I was disappointed to find that they did not come with the valve so I will have to order those from ACS. For reasons I am not clear on, they recommend stainless steel screws.

Next I went to work on the battery box for the PC680 battery. This is a steel shell that is already welded together and powder coated. It comes with steel brackets to attach it to the firewall. I located the proper position from the drawing and drilled out the rivets where the three mounting bolts will be installed. Oh Vans! Why did you tell me to put those rivets in there if you were just going to tell me to drill them out later? Anyway, once I had the holes drilled out in the firewall I clecoed the brackets on an clamped the box to the brackets. When it was aligned, I drilled the side holes through the box using the brackets as the guide. I only drilled a couple on each side then took the box off the firewall to finish the rest.

Then I needed to dimple the holes in the box with the dimples on the inside. The only way I could do this is with the pop rivet dimple dies. My friend Ron came by this morning to help out so he went to work doing the dimpling. Here is Ron dimpling away.

I dimpled the holes in the brackets also but I had to resort to the countersink bit to get them deep enough. The steel brackets don’t dimple that well. Then we riveted the brackets to the box and did a fit check on the firewall. So far so good.

Next we installed nut plates on the brackets for the mounting screws and the battery clamp bracket that will go across the top.

The plans show eight light weighting holes in the box that are optional. I though, sure, why not take out a few ounces and set up the hole saw to do this job. After 10 minutes trying to drill the first hole I gave up. The saw is just not cutting through this material. It is too hard. Later I did a search on the forums and found out this is a common problem. I wish I had read that first. So for now at least I am going to pass on the lightening holes. Fortunately, the first hole I tried to drill in on the back side against the firewall so I won’t show. I’ll need to sand and prime this area at least to provide corrosion protection.

The starter contactor was next on my list. Unfortunately there was another issue. Where the plans say to put it on the firewall it overlaps the doubler plate for the fuel line feedthru. So I had to drill that plate out and cut a notch on the upper left corner. At least I did not have to move the upper left rivet. When the plate was off I used a nut plate to locate the mounting hole for the contactor and I drilled it and installed the nut plate with the doubler plate. That locates the right mounting point for the starter contactor.

Next I located the left mounting point for the master contactor. It is defined by a nutplate that is attached using an existing rivet on the firewall (that I drilled out) and oriented along one of the stiffening ribs. So I used the nutplate as a template and drilled the holes in the firewall, then installed the nutplate in the inside. Next I measured and marked where the other two mounting holes should be located based on the drawing dimensions while Ron cut out the doubler plate to the drawing dimensions. I then drilled the four rivet holes in the doubler and marked the approximate location of the contactor holes. With both contactors mounted on one side only, I placed the doubler under them and shifted it around until it was aligned as best I could with the contactors level and the two inner contact posts overlapping the right amount to mount the copper conductor. When it looked good I drilled the doubler rivet holes, then the contactor holes. When I took of the doubler to deburr it, the contactor holes were almost exactly where I had measured and marked per the drawing.

Finally today, I scuffed the doubler plate, cleaned it an shot a coat of SEM primer on it. This will be well dry tomorrow for installation.