Started Leading Edge Landing Lights

January 16, 2011

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Well, after receiving my “install only” leading edge landing light kits from Duckworks, I was kind of eager to start fiddling with something other than rib preparation.

Today, I opened up the kits and started in on adding the leading edge landing lights.

This is from my design page, where I’ve been collecting ideas for stuff (I was originally planning 2 small MR16 (2″ sized) lights in each wingtip, one taxi, and one landing):

After reading a little more, I’ve found that people who do the two lights in each wingtip dance aren’t happy with the amount of light they are getting from their landing/taxi lights. Then, I figure out they are talking about the regular halogen bulbs provided with Van’s wingtip light kit.
The people who are using the HID wingtip lights are generally very happy with the light output.

November 2010 update: After even more reading, I’ve decide that the leading edge light is really the way to go.

Now, I think I am going to put a single HID (PAR 36 style) in each leading edge for landing lights. These won’t wig-wag.

Then, I’ll use the wingtip lights for taxi/recognition, with wig-wag. I can use the smaller MR16s in the wing, and point one set wide, and one set toward the centerline. If I use regular halogen bulbs in these, I won’t have to use a warm up circuit, which is good, considering that when up at cruise and ATC calls with a traffic alert, I’ll be able to immediately start wig-wagging them for recognition. That gets rid of my need for an automatic warm up circuit (won’t be using HIDs for wig-wagging).

I’ll figure out the mechanics of the wingtips taxi lights later (single light in each wing? 2 MR16 halogens in each wing?)

Anyway, I made the decision to go with the dual landing lights in the leading edges. I plan on flying at night, and I want the most light possible.

From Duckworks, I ordered two of the round install kits, and two H3 enclosures (spot, instead of flood). I could have ordered one spot (for landing) and one flood (for taxi), but since I’m going to do something in the tips for taxi, I want both of my leading edge lights for landing.

Anyway, here are the two kits. Very obvious are the two mounting plates, the bulb retainer, the lens retainers, a bag of hardware, and the leading edge lenses.

Duckworks was kind enough to send me a spare lens. Much appreciated.

Here are the two PAR 36 style, spot enclosures for an H3 bulb. My soon-to-arrive HID kit should have H3 bulbs that will fit nicely in here. I’ll do a separate write-up for those.

I left the bag on them to prevent getting any skin oils on them.

A closeup of the H3 part of the enclosure. I had never seen one before, so this was a learning experience for me.

Also included in the kit are the instructions, an exploded view, and the templates for the cutting and drilling.

Good documentation. Well done.

Anyway, I decided to just bite the bullet and cut into the leading edges. Here is the template with the middle cut out.

Template, ready to go.

First, I cut out the rib template and used a sharpie to mark the hole locations.

Exact positioning here isn't too important because the holes in the mounting plate are huge, and you can adjust these a fair amount.

Back to the cutout, I measured the 2.5″ from the edge of the cutout to the row of rivet lines.

Special note here, I cut the paper off on the left edge of the following picture so I could leave the ribs clecoed in. This just meant I had to measure from the cutout instead of using arrows on the side.

I also measured per the plans (18.75″ from the aft edge of the top of the leading edge skin to the top part of the opening here) and taped everything in place.

Tracing with a sharpie.

Same trace, no paper.

Other wing.

Before jumping into the actual cutting, I moved on to some of the metal preparation for the other stuff. I wanted to be able to cut the leading edge openings while the primer was drying for some of these smaller parts.

Here, I’ve run a #40 bit through all of the nutplate attach holes and enlarged the middle holes to 5/32″ per the instructions.

Then, I clecoed all 4 pieces together to countersink the nutplate attach holes for regular AN426 rivets. I could have used “oops” rivets here, but the lens retainers are thick enough that it wasn’t necessary.

4 lens retainers, clecoed together to give the countersink guide a good path.

I forgot to take any pictures of the rest of the prep for the lens retainers, lamp retainers, and the mounting plates. Anyway, they got prepped, cleaned, dried, and taken outside to prime.

I headed back in and got out a variety of dremel tools to cut out these openings.

There’s no turning back now.

I started near the bottom (least visible) and very far away from my line. As I gained confidence, I moved closer to my line (less finishing later).

Yikes, that's not a pretty cut.

After a little cleanup, they look a little better. Still need to do some final cleaning.

I didn’t take a picture of the other cutout, but it turned out equally as well. A lot of people really stress out about cutting these holes.

I can see where they are coming from, but I think the leading edges are great with these light openings in them. (I’m going to look like a 747 coming down final, which is exactly what I want (visibility and recognition).)

Pretty leading edges. (Oh, and this was the first time in a long time I've been able to work with the garage open. It was almost 40°F today!)

Okay, back to the primed parts. I had the urge to set some rivets today, and I nailed all of them. I finally feel like I’m starting to get into a groove (although squeezing really isn’t that hard.)

Here, I’ve clecoed the provided nutplates to the lens retainers.

Ready to start some riveting.

A closeup of some AN426AD3-3.5 rivets.

24 rivets set (beautifully).

Equally beautiful shop heads.

8 more rivets set (I did use "oops" rivets here).

More shop heads.

I got out one of the bulbs and just placed it in the mount just for kicks.

Looks like it will fit.

Found the screws and actually screwed them in. These things are going to look awesome.

Finally, I found all the pan-head screws and lightly screwed them in place.

Sweet.

I don’t think I’ll do any further painting of these. I like the primer grey.

I’ll do some more on the landing lights soon, but for now, I need to get back to rib prep. Hopefully this week I’ll have a writeup of the HID kit that arrives.

3.5 hours, 32 rivets. Wuhoo!

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Rolling My Own Wig-Wag Circuit

October 11, 2010


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Over the last couple months, I’ve been eyeing various landing and taxi light setups, trying to figure out what I want to do for my airplane.

I’m not super keen on the leading edge landing/taxi light setup right now, so I want to focus on putting all the lights in the wingtips.

There is a Van’s wingtip landing light kit that puts two MR16 sized bulbs in each wingtip. Supposedly, you can aim one set forward for landing (also recognition) lights, and aim the other set down for taxi.

I’ve read on the forums that people haven’t been too thrilled with this setup using the standard 35W and 50W halogens that van’s provides. Something about not getting enough light on the centerline of the aircraft, where you need it for landing.

I have also read, however, that with the MR16 HID upgrades from somewhere like www.planelights.com or duckworksav.com, there is plenty of light to go around.

Sweet. I’ll go with those. (This is the same as Mike Bullock’s setup, except instead of both sets being 50W, I’ll probably use one set of 50W HIDs for landing, and use a 35W (pronounced “less expensive”) for taxi lights.

But then we come to wig-wag. I think wig-wag (pulsing lights) for the landing lights is a requirement safety wise, so I am planning on incorporating a wig-wag circuit into my landing lights.

I could just wire them in parallel, so you turn the landing lights on, and either wig-wag them or not depending on wig-wag switch position, but because these are going to be HID bulbs, one needs to warm the bulbs up before pulsing. (I’ve read that 25 seconds was used previously on HID flashing circuits, so I’m going to use 30 seconds for now, but I may bump that up based on a crude bulb temperature test I may set up in the future.)

Procedurally, I could just wait 30 seconds after turning the landing lights on before turning on the other switch, pulsing them, but who can remember that 100% of the time? 30 seconds is just about the time it takes between turning the lights on for takeoff and liftoff. This is not the right time to be reaching down for another switch.

I’d rather flip both switches ON, and have them automatically warm up before starting to pulse.

Enter xevision. They have a multiple-hundred-dollar HID flasher box that will work great for this application.

Except I’m an engineer, and I love a good problem to solve, and I don’t have hundreds of dollars laying around.

Enter Microsoft Visio and B&C. Using Bob N’s Low Cost Wing Wag Alternative document (page 2.0) as a starting point, I drew up a concept for a  landing and wig-wag circuit with a delay timer (haven’t figured out the timer circuit yet, but it’s a relay trigger, so I’m going to simulate it with a switch for now).

Keep in mind, I could combine the functions into a 2-10 switch (similar to page 3.0 of the wig-wag document), but then I couldn’t use the switch-breaker I’m planning to use in place of the regular switch I have depicted. Maybe this circuit is a good candidate for an inline fuse…I’ll sort that out later.

Anyway, here’s the circuit for now (since I am a wiring novice, I’ll have to figure out how to connect 5 wires to one switch terminal later…I know you can’t just bolt them all on there.)

SEPARATE SWITCHES (see below for single switch diagrams)

Oh, and I’ve shown the HID lights here as just normal lights. You get the idea, though.

UPDATE: After testing, I realized I need diodes in here on the flasher side of the 2-3 switch near the NC part of the relay to isolate the two lights. I’ll try to draw them in.

 

Both switches OFF.

 

Okay, for the first iteration (see next picture), I’ve turned on the LDG LT switch. +12VDC is now available through the switch, and is going to the following places: 1) to the timer circuit, starting the 30s timer (mechanism TBD), 2) The COM terminal on the SPDT Relay (and therefore through the NC terminal to both of the WIGWIG ON terminals of that switch), and 3) to both of the WIGWIG OFF terminals of that switch.

Summary, the 30s timer as started, and both landing lights are on steady.

 

LDG ON for less than 30 secs, WW OFF.

 

At this point, if we turn the WIGWAG switch ON (see next picture), the landing lights are still getting power, but through the NC terminals of the relay, so they are both still on steady. This is good, because we don’t want them to pulse before the 30s of warm up time as elapsed.

 

LDG ON>30s, WW ON.

 

Okay, let’s turn the WIGWAG switch back off, and let the 30 seconds elapse. Now. +12VDC is now available through the switch, and is going to the following places: 1) to the timer circuit, which has now closed the relay, 2) The COM terminal on the SPDT Relay (and therefore through the NO terminal to the SSF flasher, and then to both of the WIGWIG ON terminals of that switch), and 3) to both of the WIGWIG OFF terminals of that switch.

Summary, the 30s timer has elapsed, but since the WIGWAG switch is off, we are still getting steady lights.

 

LDG ON for greater than 30 seconds, WW OFF.

 

Finally, we move the WIGWAG switch to ON, and the lights are being powered through the LDG LT switch, the trigger relay, which closes the SPDT relay, the SSF flasher, and the WIGWAG switches ON terminals.

Summary. Pulsing lights.

 

LDG ON>30s, WW ON.

 

Basically, the timer won’t let power go through the flasher until 30s after the landing lights are turned on.

The trick now will be to figure out whether I want them on one ON-ON-ON switch. (Switch positions would be OFF-LDG ONLY-WIG WAG.)

Here’s the logic table.

LDG/WINGWAG Logic Table
Time LDG LT Switch WIG WAG Switch Result
Any OFF OFF OFF
Any OFF ON OFF
<30s after
LDG->ON
ON OFF STEADY
<30s after
LDG->ON
ON ON STEADY
>30s after
LDG->ON
ON OFF STEADY
>30s after
LDG->ON
ON ON PULSE



SINGLE SWITCH

Of course, I was motivated enough to figure it out.

I think this will work.

 

OFF

 

 

LDG Only (Before 30s...if this was after 30 seconds, the timer would close the relay, but since it is unpowered, it wouldn't matter.)

 

 

Wig Wag on, but before the 30 seconds had elapsed. Still steady lights.

 

 

Then, after the 30 seconds, we have flashing.

 

Now, I figure I’m missing some diodes or something somewhere. Anyone have any suggestions?


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