Aircraft Spruce has some headset jack housings. But they were rather pricey (~$25 each). Malcolm told me about some housings he made, so I took some wood, shaped it, covered it with fiberglass, painted and then applied some release agent.
Then I covered it about 4 layers of BID with some Triax around the edges. Repeat four times and I’ve got $100 worth of headset jack housings.
To install, I cut four holes in the keel, located the position of the screws, then installed nutplates for mounting.
One of the things Malcolm does is to protect the brake lines between the gear leg and the caliper with some stainless steel spring. But we forgot that when we connected the brake lines. So until I need to disconnect them, I’ll have to get by with spiral wrap.
Here’s the existing brake line.
A closeup
Closeup after wrapping with spiral wrap
The finished brake line.
I had already mounted the EIS (Engine Information System) and the MAP (Manifold Air Pressure) Sensor. Now it’s time to start pulling wires.
I picked up some expandable braided sleeve (AKA Chinese handcuffs) from McMaster. I split out the wires that would be going to the front of the cabin, rear of the cabin and engine compartment and fed the wires through.
Connected the two DB-25 connectors to the EIS module and routed the cables into the right wiring duct. The wires going to the front of the cabin aren’t long enough so I’ll have to splice some longer wires on before running forward in the duct.
The majority of the wires go to the engine compartment. Here’s the firewall side of the right wiring duct. I used some yellow heat shrink tubing to provide additional protection for the wires. The red, yellow and white wires are for CHT and EGT probes. The rest are for various sensors and I put those in another sleeve which runs up to the terminal strip.
I’ll have to wait before I can terminate the wires for the other sensors. I didn’t have the right size heat shrink tubing for my label maker.
Here’s the EGT and CHT connections.
I’ve already done a fair amount of work on the panel layout. So I’ve got a pretty good idea where everything is going. The other day, I finally placed the first order with Grand Rapids for the panel instrumentation. I”m going to be installing a GRT HXr with remote avionics and an Android tablet option. I’ve delayed this as long as possible because new models are constantly being released. In fact, when I started this build, the HXr wasn’t an available model.
The EFIS is not symmetrical. There are knobs and buttons on the left side. What this means is that the screen is set slightly to the left. The reason this is significant is that I want the primary information display to be centered directly in front of the pilot. So the first thing I did was to identify how far to the left of the middle of the fuselage the center of the pilot seat was. Then I measured from the center of the instrument panel to the left and placed a vertical line to indicate the enter of the pilot’s vision. I then created a second vertical line to indicate the center of the EFIS box itself.
For now, I’m still using the paper EFIS display template for positioning. I drew two lines on this also: one for the display center and one for the faceplate center.
I then put the annunicator faceplate, lower switch panel, and light dimmer, servo controller and fan control panel.
As you can see, it’s rather busy. It also looks like the lighting/servo/fan controls will have to be individually mounted since the heatsinks would prevent removing the panel to the front.
Here’s the (latest) panel plan.
I was worried about the solid copper ground block and corrosion. But fellow builder John Tvedt put me on to some “Liquid Tin”. This is typically used to cover the copper traces on printed circuit boards.
So I picked up a bottle from my electronic parts distributor of choice… Mouser.
I cleaned up the copper, poured some of the solution in a plastic pan and dropped in the parts.
It reminds me of Tarn-X. As soon as the ground block hits the liquid, it changes color.
Before and after.
I also got some high-temp PVC sheet to use as a separator to prevent dissimilar metal corrosion when mounting metal to the titanium firewall.
The fuel senders which measure the level of fuel in strakes stick out into the cabin a bit. To create a cover, I took some blue foam, shaped it to the proper shape, covered it with duct tape and used it as a form with BID and carbon fiber.
When it cured, I popped out the form, trimmed away the excess fiberglass, sanded, filled and painted.
There are a number of approaches to locating the position of the nose gear up microswitch. Most of the time some method of using the nose gear door is used to indicate the gear is up. I decided to locate mine there.
I took a small piece of aluminum angle stock, cut drilled and tapped one hole for the switch. The other hole I made a clearance hole and elongated it to allow for adjusting. Then I bonded it to the inside skin of the fuselage. Once the adhesive had cured, I covered it with 2xBID.
Then I mounted the microswitch and adjusted it to activate when the nose gear door closed.
The Outside Air Temperature Probe is supplied by Grand Rapids. One of the possible issues is that the OAT is used to calculate the True Air Speed (TAS). The faster you go, the higher the air temperature will appear to the probe. So locating the probe in a spot that can measure the air temperature while not being affected by the speed of the air is desirable.
One of the functions of the NACA duct is that is allows the air to slow down. So I decided to use the nose NACA duct.
Finding the center of the duct.
The material isn’t thick enough to create a recess so I had to drill through and then create a backing plate.
From the inside with the probe (covered in plastic so the adhesive doesn’t stick to it) and the back plate.
From the outside.
Finished. I’ll have to put some filler in to make look better though.
Since I’m not going to have any traditional, panel mounted avionics, the radios, transponder, audio panel and associated boxes will all be mounted behind the panel. So I’m going to use a “Millin Shelf”. Named after Andy Millin because his is the first one I had seen. 🙂
First I made some brackets that are attached to the sides of the fuselage with structural adhesive and rivets.
Then two pieces of 1″x1″ aluminum angle stock are used to create the structure of the shelf.
Finally, a single sheet of aluminum is used to finish the shelf. Most of the devices will attach to the frame members so the aluminum sheet is used to bridge the frame members for smaller devices.
Once all the parts were assembled, I removed the shelf and began mounting the devices. Here I’ve mounted the VP-X Pro and the AHRS.
I made paper templates of the other devices (radios, transponder, GPS, etc.) and it’s going to require some careful planning to get everything to fit.
Connecting the primary alternator is pretty straightforward. Basically 3 wires. The “B” lead which supplies the power to the electrical system. The “F” (or field) lead which is what activates the alternator and a ground wire.
Here you can see the large B lead (with the white cover on it). The F lead is above and routed to the left. And the ground comes around the right side.
I wasn’t happy with how the alternator cover looked so I did some more filling and sanding. The purpose of the cover is for cooling. Air from the plenum flows into the alternator and then out the bottom through a port.
Here’s the alternator with the cover on.
And where the wires exit the cover.
