Landing Light

This week I was working on several jobs concurrently, so I’ll post updates spanning a few days, but focused on specific areas.

I wrapped up the landing lights on the left wing, and finished wiring up the landing lights for the right wing. I still need to enlarge the right wing bracket and paint the cove black, but that should be straight forward now that I’ve done it on the left wing.

The hardest part of these landing lights is the fact that I’m not working from any complete plans. I’ve spent a lot of time figuring out how to build it, which has given me a new appreciation for the step by step instructions from Vans. The wiring harness from Vans, plus the FlyLED instructions cover the wiring, but the specifics of how to put it all together needed figuring out. I wanted to build a plug on the lights to make it easy for future maintenance, so I bought some 3 wire molex connectors.

First I drilled holes and used a Dremel tool to cut a slot to hold the molex connectors.

Then I started making the wiring harnesses for the lights, with the left light first. I used a solder sleeve to create an isolated join between the ground wires. In the picture below, the flue has melted, but not the solder. Turning up the heat gun and hitting this again melted the solder and created a neat connection. Super easy.

Labels helped make sure I wired the taxi and landing lights into the right ports on the molex connector.

Added some service loops on the back so the taxi light can be removed more easily. This was probably overkill, but better to have too much than too little.

Before installing the left light into the light cove, I bench tested to make sure everything was wired correctly. All good!

I didn’t get any pictures, but I wired up a molex connector to the end of the wiring harness from Vans, and tidied up the wiring in the cove. Then I installed the light, using some locktight to secure the bolts. I’m happy with how it worked out.

I wired up and tested the right wing lights too, but I’ll need to modify and paint the light cove before installing into the right wing.

Last night and again tonight I worked on trimming the landing light bracket W-00017, so I can install the downward facing taxi-light from the Combo light set from FlyLEDs.

I guess I didn’t take pictures of it, but last week I spray painted the landing light cove on the left wing, making it a flat black color. Two days ago I primed the landing light brackets I ordered from Vans as part of their landing light kit. I ordered everything from the landing light kit except the LEDs.

It would have been much easier to trim W-00017 before installing it in the wing, but I wasn’t thinking that far ahead at the time. I couldn’t fit a nibbler inside the cove, so I had to drill holes and then enlarge using a step drill. Then some careful filing to get the right shape, without damaging the wing skin.

I wanted to get the maximum down angle on the taxi light, so I estimated the angle that the wing will sit relative to the ground (12.5 degrees), then added 10 degrees for the down angle to get 22.5 degrees. I set the taxi light at 23 degrees down and tested the fit. I needed several attempts before I was happy with the fit.

Eventually I had about 1/8 clearance between the taxi light heat sink and the W-00017 bracket.

Hard to see, but the red circle highlights the clearance between heat sink and bracket

Tonight I worked on the “Combo” landing lights from FlyLED. The lighting arrived in a box from Australia, and it was fun to unpack and explore the parts.

The Combo lights are installed in the landing light coves on the leading edges of the wings. These are designed for tail-wheel aircraft, with a cluster of 4 lights, one of which can be angled down, wired separately, and comes with a diffuser cap, to serve as a taxi light.

The largest and heaviest part of the lights are the heat sinks, which are attached to the boards with a couple of small screws and some thermal paste.

The LEDs themselves are very small, but the lenses are larger. The lenses focus and concentrate the light into beams.

Once my bench power supply arrives, I can test these out to see how bright they are.

From Sep 26 to Oct 1, I spent several sessions in the garage working on the landing light lens. Since this was my first foray into working with Plexiglass, I did some research to learn how others have done this. The use of a Dremel tool was recommended, and Vans day to never use a saw, as this will splinter the material. Plexi-bits are also required, but hard to find in the right sizes. I made my own by grinding off the edges of some existing bits, following some advice from YouTube. Then I started with the left wing.

The first steps are to trace lines on the wing and the lens, and then start trimming.

Covering the lens in tape to prevent scratches is a good idea, as is adding some tape to pull the lens into position (I used blue duct tape). I kept the tape on until I was done countersinking and fitting the lens, then I peeled it off to start cleaning up the edges.

I found that my vixen file did a nice job straightening out the sides of the lens, and my smaller round file cleaned up the edges, rounding them until smooth. I used some sand paper to clean up a few spots, then declared the lens “done”.

The screw call outs in the plans were for a slightly shorter stainless screw, but they weren’t included in the kit anywhere. I emailed Vans, they suggested using the longer screw, which I did, and recommended using a carbon screw in the future, as these tend to weaken and snap over time.

After doing the left lens over several days, I knocked out the right lens in one evening. So much faster the second time!

My only concern in this whole step is the gap that exists at the forward edge, between the lens and the wing. This will be ok for first flight, but at some point I may redo these both, or find a way to seal the gaps. When flying through rain or cloud, moisture will easy enter the light cavity.

Tonight I put my new pop rivet dimple die to work, and installed the landing light brackets on the wings. This was the first time I worked on the QB wings themselves. I practiced with the pop riveter, getting a feel for just how much pressure can/should be applied. I snapped the shanks off a couple of nails before settling on the right amount of pressure (not much). I was able to get to all of the holes with both wings in the stands, but it was also obvious I’ll need these wings on a bench to finish the job.

With the dimples set and looking good, I went ahead and riveted the two brackets (one per wing). The rivets were easy enough to buck, even in the wing stand.