I started off today by updating and printing out my connector pinout sheets for the following connectors:

• P4 – Throttle Handle AMP CPC
• P5 – Infinity Control Stick AMP CPC
• P6 – Panel Quick Disconnect (PQD) AMP CPC
• X-Bus – IBBS-Powered Avionics Bus 9-Pin D-Sub
• J3 – PQD Panel Power Connections 15-Pin D-Sub
• J4 – PQD Panel Signal Connections 37-Pin D-Sub

At the tail end of my updates my buddy Marco called.  We talked a bit on EZ stuff, and as we spoke I got to work on soldering two 16 AWG wires to the back of a 9-Pin D-Sub connector (that I repurposed from its original role as the TruTrak ADI wiring harness).

This 9-Pin D-Sub will become the new X-Bus, replacing the original 8-slot ATC fuse holder that was the X-Bus.  As per one of my very educational discussions with Bob from TCW Technologies on the IBBS install, he informed me that I don’t need to power a fuse panel since all the components powered by the IBBS must not max out past 5 amps, and the integral 10-amp mini-ATC fuse on the side of the IBBS protects these items.  I had already chucked a panel-mounted switch that manually switched IBBS power to E-Bus power (EZ’er to let the IBBS to perform this standard function), and now I was eliminating more weight and complexity by swapping out the ATC fuse panel  X-Bus for the new & improved 9-Pin D-Sub connector X-bus.

Now, I did originally plan on using two 18 AWG wires, but Bob advised to use 16 AWG wires.  They still seem like a bit of overkill to me, so I have to admit I went 16 AWG on the other 2 wires (power & ground) that Bob intoned should be 14 AWG.

Here’s a closer shot of the two 16 AWG wires to be soldered onto the back of the 9-Pin D-Sub connector that will replace the current X-Bus.

I then soldered the 16 AWG wires into place.

And prepped them with heat shrink . . .

Prior to mounting the wires/connector assembly in a D-Sub backshell.

Since I want the IBBS-to-XBus circuit to have a break in it –since the wires pass through the Napster bulkhead– to allow the wires to be run without concern of the D-Sub connector getting in the way, or if unable to traverse bulkheads, I terminated the ends of the two 16 AWG X-Bus feed wires with knife splice terminals.

Here’s a shot of the finished X-Bus cable (A side, from IBBS).

I then traced out, toned out and cut off about 9 feet of wire to trim down the four 20 AWG X-Bus feed wires coming out of the IBBS.  I toned them out to ensure I had the correct wires, then terminated them into pairs, into 1 knife splice each.  Thus, what I have is 4 wires exiting the IBBS unit, then those getting terminated into pairs with knife splices, then each pair connecting to a 16 AWG wire that feeds the X-Bus 9-Pin D-Sub connector (actually, the way I soldered all the pins together, it’s technically a 9-Pin D-Sub Buss).

I then turned my sights on the 3 pass-thru power wires and 1 main bus voltage sensor wire.  In my discussion with Bob, he said it was perfectly ok to run these all together and fuse it with 10 amps off the main bus.  So that’s exactly what I did! [Conversely, the IBBS install manual shows one fused feed to the main bus for the 3 pass-thru wires, and another fused feed for the sensor wire… always good to talk straight to the guy who designs this stuff!]

Since the other end of these 4 wires converged into one is simply a FastOn PIDG connector, I didn’t create a break in this wire group.  I merely bundle them all together and slathered with hot solder!

As you can see, I did the Bob Nuckolls’ technique of making a 2-wire pigtail from the 16 AWG wire, then wrapping that around the bundle of wires so that they are all nice and tightly snug before soldering.

Here’s my IBBS 3 pass-thru power wires and bus volt sensor wire soldered to the !6 AWG wire on its way to the main bus.

I then did the same thing for the 3 ground wires that get grounded on the panel ground block (G4).

You may have noticed that some of my wire labels are hand written.  There are 2 reasons for this: First, I ran out of the correct size wire label heat shrink (I’m waiting for an order to arrive), and second, I’m reclaiming some printed labels that fell victim to becoming obsolete when the new world order of PQD came into existence.  I prefer to be more practical than flashy, so to save money I simply lined through the old printed label on the heat shrink piece, flipped it over and ever-so-nicely printed a new, correct label on the other side.

In hindsight, I should have taken a pic of the entire IBBS wiring harness before I started this process to contrast with what you see below, which is just a few random pics of the completed IBBS wiring harness.

I have 3 wires out of the original 14 that did not get cut or combined:

• IBBS Master Switch (to panel switch)
• Info lead (to GRT HXr EFIS…via J4)
• IBBS Low Voltage Warning (to AG6 Warning Annunciator)

And the wires that did get cut & combined:

• 4 X-Bus Power leads into 2x 16AWG wires
• 3 Pass-thru Power wires & 1 Bus Volt Sensing wire into 1x 16AWG wire
• 3 Ground wires into 1x 16AWG wire

Among other things, this simply means that I now have half the wires to keep track of (7 vs 14) coming off the IBBS wiring harness, and fewer wires passing through the Napster bulkhead.

One final point of note.  Due to how the IBBS box is mount vertically on the front left face of Napster, as the wires in the harness exit the IBBS D-Sub connector they must immediately make a U-Turn to get keep from dragging on the floor of the nose battery compartment.  One of my first tasks tonight was to place a large piece of black heat shrink over all the wires in the harness.  Then before applying heat, I zip-tied the harness back onto itself in a “U” shape.  I then heat up & shrank the tubing and it kept its “U” shape perfectly.  Pretty cool!

Tomorrow I’ll continue to work on both the Triparagon & the wiring in/about the avionics bay.

Technically, I started off today by spending about 2 hours finishing up my blog & tweaking this website.

I then called Bob at TCW Technologies and had a good discussion on connecting the IBBS power cables to the 9-pin D-Sub connector that will be the new X-Bus (vs the ATC fuse panel).

I then went down to the shop, marked up the front top edge of the Triparagon cross shelf in the location where I would drill the beginning holes for the rivets that will secure the parts mounting overhang tabs.

My first real action though was drilling the front & aft rivet holes on the mounting flanges that secures the cross shelf to the vertical plate.  These are the first 2 of 4 total larger diameter rivets that I’ll use to secure connect these Triparagon pieces.  I couldn’t actually press the rivets in place since I can’t get in there with my rivet pressing tool, so I’ll have to mount the rivets when I remove the vertical Triparagon plate.

I drilled the aft rivet hole first (right, above) since the cross shelf needed to come up about 0.070″ on the front side to be at 0° level, which is what the double-checked longerons showed.  After drilling the front side & inserting the rivet, I confirmed that the cross shelf was still level from front to back, matching the 0° longeron level… which you can see it did!

I took this shot specifically to show the 6 countersunk screw positions that are used to hold the cross shelf to the vertical plate via the angled mount extrusions and nutplates. You may note in the next pic that the nice aluminum material in the areas between the pairs of countersink holes were targeted for lightening… Yes, the weight loss program continues!

In the pic above you can see all the dots along the leading edge of the top cross shelf where I marked the it for the rivet drill points.  I then drilled a 1/16″ pilot hole at each dot where I would be installing a rivet.  I then I clamped each overhang piece in place, drilled the #40 hole through the cross shelf pilot holes into the overhang extrusion clamped underneath.  I then deburred all the rivet holes, and then mounted one overhang at a time.  I would drill the countersink on a rivet hole, press the rivet into place and then move onto the next rivet.  You can see all the rivets installed below, which of course means that the overhangs are mounted.  Also note there are a number of new lightening holes.  After I drilled the new lightening holes, I spent a good 20 minutes cleaning up the rough edges of the larger cross shelf lightening holes.

The overhangs have the dual purpose of providing a mounting surface for the CrackerJack parts, and also to provide a flange to mount the upcoming diagonal supports that will secure the outboard ends of the cross shelf to the upper mid-point area of the vertical plate.  You can see that I pre-identified the locations for the airspeed switches and drilled the mounting holes on the overhangs before riveting them in place.

Here’s a shot of the overhang rivets . . .

And a shot of the entire Triparagon cross shelf . . . in repose!  ha!  I weighed the cross shelf with its attached brackets, and with the new lightening holes it weighs in at 0.476 lbs. Add that to 0.7 lbs of the vertical upright (which will get another round of lightening holes) and I get a respectable 1.176 lbs total currently.  Again, I suspect that I’ll come in at about 1.1 lbs for final Triparagon install weight.

I then mocked up and test mounted my Crackerjack parts, aka airspeed switches, onto the front overhang mounting tabs.  Note that airspeed #1 is mounted on the right side (left in the pic) on the aft side of the overhang tab staggered behind and just to the left (looking from front) of airspeed switch #2.  I mounted airspeed #1 to allow me to adjust the target airspeed set point with the setscrew.

I then spent a good couple of hours updating my IBBS wiring diagram and determining the pinouts for my PQD (Panel Quick Disconnect) connectors.

Tomorrow I’ll continue working on the Triparagon and the avionics bay electrical wiring stuff.  I figure I have at least another good week to finalize this round of electrical system stuff before moving on to the wheel pants!

As I was finalizing my last blog post the doorbell rang. It was my mailman delivering my order from Stein, so after I finished up my blog post I opened up the box to check out all the goodies.  I took the 6-pin mini-Molex and quickly mounted the B-side to the roll trim cable. I already had labels made up so I quickly labeled both sides of the J5 jack as well. (As a reminder, my labeling scheme for connectors is quite simple: the “A” means it’s closer to the nose while “B” means tail side.  If the connector or jack is vertical, then the hard mounted side is “A” and the removal side is “B”).

I then took a few minutes to prep the fuselage for me to sit in it and make some airplane noises.  I needed to figure out where my Dynon intercom box is going to call home, so I pulled the wood blocks out from under the nose wheel, cleaned the tools and extraneous components out of the front seat and climbed in.  I discovered that I can reach back and manipulate the controls of the intercom if it’s against the right fuselage sidewall, just aft of the stick.  How about 2″ aft of the stick? … uh, nope, not really.  Too difficult there.  But half an inch back I can curl my hand down comfortably and work the intercom controls.

I like this position because it’s really unclaimed, unused real estate that can be put to good use.  Also, I’ve had my eye on the left armrest area just forward of the throttle quadrant to use for my environmental controls panel.  Now that I’ve decided to put the Dynon intercom on the right armrest console just aft of the stick I can reclaim the forward left armrest console for the environment controls!

In addition, in thinking about where my intercom control head would go, I naturally wondered where I was going to put my headset jacks.  I’ve discussed this with Marco in the past, and we had yet another quick exchange about it via text.  I really wanted to keep the headphone jacks off the panel, but where to put them?  After doing a bit of research last night, I would like to give a shout out to Nate Mullins –and in turn, James Redmon– for highlighting the very aft side of the armrest for being a good location.  Now, they picked the aft side of the left armrest to mount their jacks, but I’m leaning towards the right for 3 reasons:

1. It keeps the headset wires on the right side of the seat when ingressing/egressing the aircraft.
2. It keeps the electrical wires on the right side of the aircraft (power wires right, antenna cables left), and
3. It keeps the shielded wire run betwixt intercom box and jack very short, and since  this specific wire run is the most susceptible to gremlins and things that go staticky in the night, I would rather keep it as short (aka noise free) as possible.

So that’s 2 fairly significant component placement decisions that I made today…. after literally years of those questions floating around in the recesses of my mind.

Ok, on to the task at hand: wiring the throttle handle.

While down in the shop I collected up my throttle-handle-mounted nose gear switch that I had gooped up the aft end of with E6000 to secure the wires both to each other and to the switch body. Since these switches are older (but still look in great shape) and I had to wrangle off the massive amounts of old wiring, I want to make sure both the solder connections and switch connecting tabs stay secure, and are subjected to as little vibration as possible.

Here’s another shot of the E6000 gooped-up nose gear switch.

To finalize my wire-securing process on the nose gear switch, I added 2 pieces of heat shrink around the base of the wires and goop.

I then added a piece of heat shrink that secured the wire/goop subassembly to the body of the switch.

I had to run down to my favorite hardware store to pick up a 2-56 stainless steel CS screw since I apparently lost one of the nose gear switch’s mounting screw somewhere.  I test fitted the screws, took it back apart and then judiciously used some E6000 on the screws and around the base of the switch mount before permanently remounting the nose gear switch into place on the throttle handle.

Here’s how the developing rat’s nest of wires looked after I added the nose gear switch.

I should note that before I ran out to get the missing 2-56 screw (try finding one of those when you don’t know where it ran off to!) I gooped up the wires/switch intersection of the landing brake switch with E6000.  Here are a couple of slightly fuzzy pics to show you how it looked when it cured.

I then repeated the heat shrink process on the wire/goop area of the landing brake switch.

Then secured it to the switch body with a clear piece of heat shrink.

I then installed the bottom and last switch for the landing brake into the throttle handle.

At this point it was time to start connecting all the throttle handle switches’ wire leads to the blue cable.  I spent a good 3 hours soldering all the switch lead wires to the blue cable harness wires.  I had already identified which wires in the blue cable were 22 AWG and which ones were 20 AWG, and had to account for this when wiring up the switches.  I did only 2-3 wires at a time, ensured they toned out, then added heat shrink (that I had to ensure was on the wires before I started soldering) over the solder joint before moving onto the next few wires.

Then it was time to start cramming… wires that is.  There was actually enough room in the throttle handle housing to stuff all the wires back into it comfortably.  As you can see I reclaimed one of the ring connectors from the original harness and pigtailed it off the ground wire for ground to the throttle handle housing.  You can also see that in this and subsequent pics that I finalized securing the two extra 18 AWG wires spiraled about the blue cable.  I also labeled the cable and added lengths of heat shrink to secure the two 18 AWG wires.

I then remounted the throttle handle side plate cover with the 3 original screws.

Here’s a shot of the throttle handle with all the switches rewired & remounted and the cable prepped for having an AMP CPC connector terminated onto it.

I then terminated all the wires with AMP CPC connector sockets.

Since I had NOT actually created the pinout scheme for the P4 connector, I stopped work and spent a good 45 minutes determining the pinouts for this connector.  Once done, I toned out the wires to ensure both continuity and to check wire IDs since there were multiple wires for each color (e.g. lots of red & black wires).  As I determined what wire was what I then placed them into their appropriate numbered socket hole.

Here’s a closer shot of the throttle handle switch wiring terminated into the AMP CPC connector housing.

And here’s a shot of the front face of the P4 (B-side) AMP CPC connector.

I then secured the wires with silicon rubber self-sealing tape before finalizing the cable clamp install.

I then mounted the cable clamp to finish the throttle handle cable.

Here’s a shot of the full length throttle handle cable.

And a final shot of the throttle handle and P4 connector.

Tomorrow I’ll be back working in the avionics bay, both on getting Adel clamp hard points installed and finishing up the Triparagon.

This post covers today and yesterday since I was remiss in posting yesterday.  This weekend has been a busy one both socially and of course with football (yes, I’m an avowed football junky!).

Ya’ll have probably noticed that as I work on any one component, I like to knock out those components directly around it since I’m already “in the groove,” plus it gets those items finished.  In addition, I already know how they fit into the area that I’m working. I understand that my build methodology is somewhat organic, and often unscripted, but staying motivated and simply getting many productive hours in on the build a day is the key to having an airplane sitting on the ramp vs a project in your garage, right?!

And so it is with my electrical system.  There are a myriad of low hanging fruits right now that I’m simply going to knock out: changing as many variables into constants and resolving as many unknowns as I can at this point in the build.

Thus, it is that one of those low hanging fruits right now is the throttle handle.  As I’ve stated before, especially in an airplane as space constrained as a Long-EZ, I am a total believer in maximizing the HOTAS (Hands on Throttle and Stick) concept as much as possible.  If it’s good enough for task-saturated military fighter pilots, it should work fairly well for us too.

I started off yesterday by determining my wiring gage requirements for the throttle switches.  I then assessed the 17 wires in the 2+ ft of leftover blue cable that I cut off the Infinity stick grip.  After listing out all the wires and gages, I determined that I could I repurpose this leftover blue cable for the throttle handle switches.  Since there’s only 17 wires in the cable, I’ll also run two 18 AWG wires for the landing brake along the outside of the blue cable, for a total of 19 wires to the P4 AMP CPC connector.

I then got to work widening the mounting hole diameter for my 5-way castle switch (“joystick”) that controls a few A → B options on the GPS (i.e. GPS to VLOC) or page/screen scrolling functions (Trio fuel screens, GRT screen flips, etc).

A few months ago I picked up these drill bits specifically for this task: the 39/64″ bit to drill out the majority of the hole diameter, then the 19/32″ bit to fine tune the hole size.

Here’s the hole post drilling, ready for the 5-position switch.

The switch has a plastic keyway on the side for positioning.  Of course I could have removed it, but I decided to leave it in place and notch the side of the hole.  I clocked the switch position so that not only are the finger grips in the 3-6-9-12 O’clock positions, but also so that the ground connector tab was closest to the backside handle opening.

After notching the hole for the switch’s keyway, I then test fitted the switch.  So far I’m very happy with how this switch is working out!

Here’s an inside-handle shot of the 5-way switch, with the ground connector tab on the aft side of the switch closest to the handle opening.

Here’s a shot of the back side of the 5-position switch.  Note that the ground tab is the tab on the far left, away from the center 5 tabs..

I then cut, stripped & soldered the 5 switch position wires and the ground wire onto the tabs on the backside of the 5-position switch.

Another shot of the wires soldered onto the 5-position switch.

On the 2 other top mounted throttle push button switches… since I couldn’t get these switches out of the throttle handle without destroying or marring them greatly, I simply used the wires that were attached to the switches and soldered them to the identified wires in the leftover blue cable that I cut off the Infinity stick grip.

Well, after getting these 2 switches wires soldered to the blue cable wires, I then toned them out for continuity.  When I check continuity on my Fluke multimeter, I generally just check for sound and call it good.  But this time I actually caught sight of the resistance reading, which was on the order of 6 & 9 ohms for the respective switches. Whoa, pretty high resistance for basic momentary push button switches, what was going on?  Well, under closer inspection I realized that the heat shrink over the wires at the switches wasn’t just wires, there were resistors in line as as well.  Of course I don’t need resistors for these 2 switches, so they had to go.

After I removed the offending resistors, then the issue became soldering the switch leads onto the switch posts down in the very depths of the throttle handle housing.  Hmmm, I’m decent at soldering, but this proved to be a bit challenging.  I did it, but my confidence in the physical strength of the solder joints wasn’t as high to my liking, so I did what any responsible builder would do, I reinforced those solder joints by burying them in potting goop!  After testing the switches electrical continuity (good) and checking that the resistance was back down into the normal range (0.2Ω), I then used E6000 to cover up the freshly soldered switch lead wire joints.

I went ahead and ran a strip of labels and printed off a few to label the switches on the inside of the throttle handle.

I then got to work on the SW024, the transponder Ident button & SmartStart arming switch.  I cleaned up the switch wire tabs and soldered the correct colored wires to the tabs.

I then mounted the 5-position switch (SW020) and remounted the transponder Ident & SmartStart arming switch (SW024) into the throttle handle using RTV silicone, and set it aside to cure.

As the 2 freshly added throttle handle switches cured, I then got to work on the nose gear UP & DOWN switch.  Again, I verified the correct size and colors of the wires, then soldered them into place.

I then finished off the mojamma of the throttle handles switches, the landing brake switch with its multiple cross-pairs of wires.

Here’s a shot of the day’s tasks, with a total of 4 out of the 6 switches installed.

Tomorrow I’ll install the last 2 switches and finalize the wiring on the throttle cable, to include termination the blue cable into the P4 AMP CPC connector (B side).

Today was kind of a light build day.  I did finalize and submit orders to SteinAir and ACS, but I also wanted to knock out the 5-wire roll trim & ELT GPS signal cable that piggybacks off the Infinity stick grip’s P5 connector.

I started by trimming back the outer cable sheath and collected up my 5 mini-Molex sockets.  This first end that I terminated was for the P5 connector side since all these sockets will mount into a 6-pin mini-Molex connector housing (J5) that I just ordered from Stein.

Here’s the mini-Molex connectors terminated on the P5/J5 connector side of the 5-wire roll trim & ELT GPS signal cable.  Although this cable does of course include the ELT GPS signal cable, I have given it the moniker –and label– of simply the “ROLL TRIM cable.”

I then terminated the 5-individual wires on the roll trim servo end.  The J6 mini-Molex connector on that end is only a 4-pin connector, since that is all that is required to drive the Roll Trim’s RAC T2-10A servo.  I separated out the ELT GPS signal wire and terminated it with a D-Sub pin for future connection with the ELT GPS feed that will have a D-Sub socket.  I then terminated the other 4 wires with mini-Molex sockets.  I then added heat shrink to the wires groups.

Here’s a closer shot at both ends of the Roll Trim Cable.

Here’s the J6 4-pin mini-Molex connector (A side) on the Roll Trim servo side, and the ELT GPS signal wire.

And a look at the entire Roll Trim system.

I was playing around a bit (dismantling) the odd, heavy, large joystick-type switch that came in the throttle handle when I found this guy buried inside of it.  It’s a rather large press-in-fit momentary on-off switch that I’m going to press into service as my GIB PTT button!

My final act of the evening as I watched Thursday night football was to finalize the rewiring of the TruTrak ADI wiring harness by twisting the whopping three 22 AWG wires together and then installing the backshell to the 9-pin D-Sub connector.  I included the originally installed harness wires in this pic to again show how huge they were/are (14-18 ga)!

Tomorrow will be a light build day since I’m heading out mid-afternoon for a social engagement.  I will try to get a bit more done on the Triparagon structure though (and stop sloughing off since there’s no football games tomorrow!)

First off, as you can see I’ve settled on the acronym PQD, Panel Quick Disconnect, to describe the connectors and bracket that I’ll be employing to make the task of removing the instrument panel infinitely EZier than without this configuration.  Although there will be some wires & components that will not be disconnected, either through their location just off the upper main Aluminum panel face, or because their wiring is not conducive to being split by a mid-point connector (eg Avidyne IFD COM plug P1002 & Dynon intercom wiring harness).

Speaking of the “upper main Aluminum panel face,” after some impromptu research I’ve decided that since I’m keeping a very large portion of the original panel in tact for strength behind the Aluminum panel face, that I’ll be using 0.063″ 2024T3 for the instrument panel. I was actually in the process of ordering that panel from ACS, when I double checked my spreadsheet and lo & behold, I had a spare 2′ x 2′ panel on hand from years ago.  Woo-hoo!

Ok, back to the PQD.  I had originally ordered a 1/8″ thick 2-1/2″ x 2-1/2″ angled piece of 2024 from McMaster-Carr quite a while ago thinking that I would hang a bunch of stuff off these cross shelf overhangs in the same fashion that I’m doing now with the clearly much smaller sized 1″ x 1″ angled aluminum overhangs.  This angled aluminum extrusion was just too big & heavy to use in any reasonable quantity, plus as my Triparagon design matured I just didn’t have a need for it.  So into the massive spare pile of aluminum it went.

Then when I was finally hit between the eyes seeing Paul Dye’s panel on the VAF forum as I was trolling for pitot-static info, I finalized my decision to make my panel fully & EZily removable. So I had to get serious on both the quantity & type of connectors to use and where they would reside.  I had had a nascent thought all along of a drop down bracket on the aft right corner of the Triparagon cross shelf IF I did the fully removable panel mod.  Well again, it was time to get really serious so out came the big gun: the 1/8″ thick 2-1/2″ x 2-1/2″ angled 2024.  If you remember I posted a few days ago, over the Thanksgiving holiday, a mockup of my connectors on the end of this massive 2′ long piece of aluminum. With my electrical connections confirmed, and with the only mod to the actual connectors being that I swapped out the 19-pin AMP CPC connector for a higher capacity 24-pin connector (same diameter), I was ready to install the J3, J4 & P6 connectors into the PQD bracket, and of course make the PQD bracket itself.

I started by marking the connector outlines on the angled extrusion.

I then used a hole saw to drill the 1-1/2″ diameter hole for the P6 AMP CPC connector.

Of course I had to check the fit…. looking good so far!

Then came the odd shaped 37-pin & 15-pin D-Sub connectors.  I figured this would be a total hand-jam custom build process (“custom” means it works fine, but it ain’t always pretty!).  I drilled some small starter holes, focusing especially on the corners.

I then expanded out the center area holes with a large diameter drill bit, which is the same diameter as the width of the D-Sub connectors.

I then employed my jig saw –and a few expletives!– to finalize the cutouts for the D-Sub connectors.  Here’s a shot of the initial rough connector cutouts in the beginnings of the PQD bracket.

And another shot after I cut the bracket out of the angled 2024 extrusion (it was raining so I plunged forward using my Skil saw to cut the bracket out!).

I then test fitted the connectors in the PQD bracket.

Here’s a shot of the backside of the connectors test mounted into the PQD bracket.

I then took the PQD bracket upstairs and mocked it up on my Triparagon cross shelf. After finalizing the mounting location for the PQD bracket on the cross shelf, I then digressed a bit from the PQD bracket and figured out where my first round of lightening holes would go on the cross shelf.

I took the cross shelf and the PQD bracket down to the shop and proceeded to drill the mounting holes for the bracket into the bracket tab and the cross shelf.  I then added 3 K1000-8 nutplates to the PQD bracket mounting tab.  As you can see, I also drilled 4 lightening holes in to bracket’s mounting tab.

Here’s a view of the top of the PQD bracket mounting tab, with the flush rivets of the 3 K1000-3 nutplates visible.

I then diverged from working on the PQD bracket for a bit and drilled out the first round of a bunch of lightening holes into the Triparagon cross shelf.  After finishing round one of lightening holes, I then went back to work on the PQD bracket and drilled countersinks for each of the 3 -8 screws into the top of the Triparagon cross shelf (shown 2 pics below).  I then mounted the PQD bracket to the cross shelf.

I then test fit the cross shelf back onto the vertical Triparagon plate.  Note the 3 countersunk -8 screws securing the PQD bracket into place.  (Note: while I was drilling the PQD bracket mounting holes through the mounting bracket into the cross shelf, the bracket misaligned slightly.  Nothing earth shattering, but definitely a slightly-sloppy mounting AND a loss of cool points!)

After I finished with the PQD bracket mounting on the Triparagon cross shelf, I headed out the door to an auto racing shop just across the river in Maryland that sells some high end stuff.  I knew that they sold the same quick disconnect fittings that I’m using for my pitot-static system, so I wanted to take a quick break from the build and take a gander.  Well, it had been raining all day, but there seemed to be a lull.  So I grabbed the keys to the shed, pulled out my table saw and trimmed down the 1″ x 1″ angled 2024 aluminum extrusions that will serve as my Triparagon cross shelf mounting tab overhangs.

I trimmed these angled extrusions down on the sides that will mount to the front underside edge of the Triparagon cross shelf.  I took 0.4″ off, with the obvious resulting width of the top horizontal extrusion arm being 0.6″.  This took all of 10 minutes, and it actually started sprinkling again as I was putting the saw back away in the shed.  With my overhang extrusions cut, I was then off to the racing shop in Maryland.

As a reminder, besides simple weight savings, I wanted to trim down the left side angled extrusion, specifically, to allow me to mount the M760REM COM2 radio about 0.4″ forward on the left underside of the Triparagon cross shelf.  This served to better deconflict the mounting screw placements between the COM2 radio and the GRT GADAHRS that’s mounted on the top side of the cross shelf.  The right extrusion was merely along for the ride since I might as well make them symmetrical, right?!

Back from the racing shop, and my quest to replace the #40 drill bit that I broke (to no avail), I got back to work. After I collected up the right sized bits for drilling the connector mounting holes into the PQD bracket, I decided to take yet another slight detour to finalize a task that needed finishing: the right-side avionics wall bracket for the P3 & P5 connectors.  I drilled out the 8 total connector mounting screw holes and then did a final cleanup on the bracket by sanding down the edges and ridding it of excess glass fibers around all the holes.  I then test mounted both the P3 & P5 connectors.  I brought down the Trio A/P wiring harness from upstairs to test fit the other side of the P3 connector [confession time: I spent a good 10 minutes looking for that darn P3 connector just to finally realize that I had mounted it to the end of the Trio wiring harness pitch servo cable!].  You can see that I also set the 2 white auto trim wired into the back of the P3 connector as well.

Here’s a longer shot of the P3-A/P Pitch Servo and P5-Infinity Stick Grip connectors test fitted and mocked up in place.

Moving on with more connectors, I then mocked up the PQD connectors P6, J3, and J4.

Since I was holding the camera down low taking low-to-high angle shots of the PQD bracket through the right leg hole, I took a few rounds to ensure that I got a good pic.  I had to leave this one in the mix since it looks like something out of Star Wars with a pure beam of energy coming out of the back of the P6 connector.  That’s right folks… no wires for me! Just pure energy transfer in my ship!  HA!

Here’s another shot of the PQD bracket and its connectors.  Note that although I originally wanted to mount the D-Sub connectors on the aft side of the PQD bracket (which would be the forward side of the plane), it initially appears that the connection hardware with the mating side D-Sub connectors will be tough to do if I left them aft-bracket-side mounted. I’ll play around with the hardware a bit, but I think that this will most likely be the mounting configuration for these connectors.

An issue that I noted was after I test fitted the aft side P6 connector’s cable clamp: Hmm, don’t think it’s going to fit since the gap spacing between the cable clamp and the panel is only about 2-5/8″.  It would most likely actually fit, but then of course all the wires would exit and then immediately have to take a hard 90° turn to get to their final destination.  Not good.  So . . .

Be gone vile & wicked cable clamp! (said in thick British villain voice… sorry, my Brit Canardian Peeps.  ha!)

Ok, much better!  As you can see with the P6 connector cable clamp removed I get about another 1.5″ clearance and 4″ spacing overall.  Still slightly tight, but since the GRT HXr EFIS is low profile on the backside this is EZily workable.

And yet another shot showing all my current Avionics Bay connectors.

I reordered my blog post pics just a bit to make the topic flow a bit EZier to follow.  If you looked closely in my Avionics Bay pic above, you may have noted that I drilled a hole into the triangular panel support and added another RivNut for the second & final Adel clamp that will also be used for the Infinity Stick Grip cable routing from the stick to the P5 connector.  I also added a couple of layers of BID on the bottom side of the support triangle to beef up the RivNut mounting.

Back on the Triparagon cross shelf, with the PQD bracket configured & installed, I then started in on some of the final pieces parts (aka “CrackerJack Bits”) that I need to mount to round out the final electrical system components install on the Triparagon.   I found a good spot for the Piezo Warning Horn on the right underside of the cross shelf. I mocked it up, ensuring it had good clearance with the vertical Triparagon components (it’s close to, but not touching, one of the mounting screws to the right side AG6 warning annunciator). I drilled the holes for #6 mounting screws and then countersunk the 2 screws on the top side of the cross shelf.

Here’s a closer shot of the mounted Piezo Warning Horn with the #6 mounting screws installed.  I used standard nuts on the screws to mock up the warning horn & make it EZily removable.

I then test fitted the Triparagon cross shelf onto the vertical plate to double check the clearance between the warning horn and other Triparagon components.  In the pic below you can see the 2 countersunk #6 screws, and the warning horn itself through the lightening hole.

Here’s a final shot of the mounted Piezo Warning Horn on the right underside of the Triparagon cross shelf (pic taken from the front of plane).  You can see that it’s close in line to the wiring bundles that will spew forth from the PQD bracket, but also clearly not in the way either.

I then brought my cardboard component mockups that I made a year or so back to check out their general fit on the Triparagon cross shelf.  Below you can see the GRT GADAHRS (their new term for their new AHRS) and the Trig TT22 Transponder behind the GADAHRS.

Another shot of the cardboard GADAHRS & XPDR mockups.

Just an idea of the fit of the Trig TT22 Transponder on the Triparagon cross shelf.

And the cardboard GADAHRS and XPDR on the Triparagon cross shelf with the rest of the left side Triparagon in view.

Since there’s forecasted high winds tomorrow, and thus no flying, I’ll continue my quest to finalize the Triparagon cross shelf and resident components install.  I will be doing some more sideline wiring on my components since currently they’re EZ low hanging fruit, and don’t conflict with other parts of the build (like so many other build actions do at this point!).  It doesn’t look like to much longer before I’ll be back on the . . .  Yes, WHEEL PANTS!

Yep, today I employed a rudimentary list-form version of the Karnaugh map, or k-map to figure out the circuits going to/from the respective A & B sides of the 3 connectors that I’m using to enable a fairly quick-disconnect of my instrument panel.  If you’re wondering what a k-map is, it’s used in Boolean Algebra and reduction to reduce a multitude of circuits down into the least number of circuits possible and still get all the correct functions out of an integrated circuit chip.  Or, as that Internet thing puts it, “Karnaugh mapping is a graphic technique for reducing a Sum-of-Products (SOP) expression to its minimum form.”

Although not overly difficult, it was of course time consuming to go through literally every wire & component to ascertain its relationship to the panel.  Moreover, since I had finalized all the I/O requirements (yes, this is still an airplane building blog, NOT a computer forum… ha!) for my throttle handle switches, I realized as I was building the new connector diagrams that with a little internal (to the throttle handle) consolidation of 3 ground wires, that I only needed exactly 19-pins for the throttle handle connector.  Thus, I could then swap out the 24-pin connector that I had planned on using for the throttle with the now “old” 19-pin connector that I had on hand for the recently put-out-to-pasture GIB Infinity control stick (AKA “the really expensive spare control stick”).  The new configuration for my 3 connectors (I’m going to have to come up with a reference name to identify these things! . . . I’m leaning toward the “PQD (Panel Quick Disconnect”) is as follows:

• P6: 24-pin AMP CPC – Thick wires/high power & ground connections
• J3: 15-pin D-Sub – Thin wires/low power & ground connections
• J4: 37-pin D-Sub – RS232 data & low power transfer connections

With the PQD connectors (trying it out . . . ) squared away I then decided that before I put away the Trio Pro Pilot autopilot wiring harness I would cut & terminate the shielded 4-wire cable for the pitch servo.  I took it down to the shop and determined the required length.  I then cut it WAY shorter than how it comes from Trio.  The excess cable that I cut off is visible above the harness in the pic below (post terminated connectors).

As with shielded cables, I carefully stripped the outer cable jacket and consolidated the shielding wire to one side.  After twisting it and cutting it down to about a 0.3″ pigtail, I then soldered a piece of black 22 AWG wire to the pigtail.  I then terminated the black pigtail wire in tandem in an AMP CPC socket with the identified ground wire of the 4 wires. I then terminated the other 3 wires with sockets as well.  Also, I added a piece of black heat shrink over the soldered joint to protect the joint and add a bit of strength to the cable for when I eventually set the connector cable clamp in place.  Finally, as I did with the roll servo cable, I performed an electrical continuity check on each wire to ensure my connector terminations were good.

This concludes the connector upgrades for the autopilot’s pitch & roll servos, and the wiring harness pitch & roll servo cable feeds.  The roll servo connector (below right) is pretty much complete, but I haven’t finalized it 100% since I will have to remove the connector to route the cable down the fuselage side & through the firewall.  As for the pitch servo cable (below left), I still need to terminate the 2 autotrim wires and install those into the connector when it gets installed “for good” in the plane.

The last task of the evening was to review the mounting spacing of the Trig TT22 Transponder on the topside of the Triparagon cross shelf since it could potentially affect the mounting of both the front 1″ overhang on right-side cross shelf, as well as the PQD junction mount on the aft right side of the cross shelf (both on the underside of the cross shelf).

It’s dark & cold out right now so I’ll wait until tomorrow to cut the PQD Aluminum angle mounting bracket, as well as narrow down each of the forward 1″ x 1″ angled Aluminum cross shelf overhang tabs (for the CrackerJack parts) by about 0.4″, resulting in 0.6″ wide top arms.  I’ll also assess all the wiring going through the PQD connectors to ensure the wires are physically inserted in a logical manner to keep the wire bundles as free-flowing and stress free as possible.