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.

I didn’t go flying today due to high winds, so I started off with a little cleanup action on the nose gear wiring harness.  I’ve had a bundle of excess wires sitting on top of the NG30 cover for eons now and decided it was time to clear them off.  Also, instead of using butt connectors I opted for a more “elegant” solution and spliced the wires using a pigtail to secure the stripped ends of the individual wires together before soldering them.

Here is the first set of 3 that I did this morning.  You can see the long 3-4 wire pigtail that I teased out of the stripped red wire on the left before cutting the rest of the stripped wires short in length to match the white wire on the right.

I then used the pigtail to secure the 2 wires together.  I could have used a wire or two less on the pigtail and also cut it a bit shorter, which added to the slight excess in the wrap. No worries though, it still worked great.

I then soldered the wires together.  I actually added just a tad bit more solder after I took the pic below.

Here’s wire set #2 getting spliced . . .

. . .  then soldered.

And wire set #3 completed in the same fashion.

Here you can see all 3 wire sets spliced & soldered together.  I used shrink tubing over the joint for added joint strength, then simply used the label as a second layer over the shrink tubing for even more added strength.  After I finished with the shrink tubing & labels, I then hooked up up the battery leads and ran the nose gear up & down a bit to ensure the splices were carrying current, which they did.

This morning at breakfast I drew up a plan for a bracket that would hold the AMP CPC connectors P3 (A/P pitch trim servo) and P5 (pilot stick grip) in place on the avionics bay sidewall.

I decided to go ahead and knock this out so that the glass would be laid up and curing overnight.  For the bracket material I figured I would use some leftover 1/16″ thick G10 that I had on hand.  I was going to use some of my 1/16″ brown phenolic at first, but it cuts a little easier than the G10 so I’m saving it to continue using for my nutplate backers.

So I cut off a 3.5″ long piece off the 2.2″ wide strip of G10.  I then rounded the front corners.

And drilled 2 pilot holes to mark the center of the larger holes.

Which I then drilled next… along with the small #40 & #6 size screw holes, respectively of course!

After finalizing my mounting location, I then 5-min glued the bracket into place on the sidewall.  I screwed the aft corner of the bracket to a clamped 2×4 piece to keep the bracket aligned while the 5-min glue cured.

While the AMP CPC connector bracket 5-min glue cured, I got to work on the Triparagon cross shelf.  I marked out where the GRT GADAHRS will get mounted along with the centerline, then configured the angled mounting bracket locations.  I marked the mounting screw locations on the angled mounting brackets, then took the angled brackets and the cross shelf down to the shop to drill the holes.

After I got the 3 mounting screw holes aligned & drilled, I then riveted nutplates to the left angle bracket.

I then countersunk the 3 left side screw holes on the top of the Triparagon cross shelf and then screwed the shelf to the left side angle bracket.

Here’s a top view of the 3 left side countersunk screws.

I then quickly mocked up the Triparagon cross shelf.  Again, I really am liking how the Triparagon is coming along.

My last official act of the evening was to stop making noise and start making some fumes… epoxy fumes that is.  I whipped up some epoxy and laid up 2 plies of BID on the top side of the AMP CPC connector bracket.  I did use a flox fillet so the glass would transition well between the wall and the bracket. And of course I finished off the layup with some peel ply.

If the winds stop acting up I’ll be flying tomorrow afternoon.  Still, tomorrow I will try to get the Triparagon cross shelf mounted, as well as the bottom/final glass laid up on the connector bracket.

I started out today by trimming the reglassed aft lower Triparagon nutplate mounting tab with the Fein saw.  I then cleaned it up by sanding down the edges and then redrilled the hole to allow me to thread in the mounting bolt, which as you can see I’ve done below.

I then labeled the power wires coming off my Atkinson pitch trim servo motor with heat shrink labels on both ends of the wire.  As you can see I had to unravel the twisted wire then retwist them back together after the labels were on.  However, since the servo motor came from the supplier with these wires, I wanted to test them to see how they held up under heat & fire.  I snipped a test piece off and tried to burn it with a lighter for a good couple of minutes to no avail.  With my impromptu wire fire rating test complete, I then went ahead and affixed the labels and retwisted the wires.

With all my mounting tabs good at this point, I then brought the Triparagon down to the shop and officially mounted it!  Here’s a shot of the right side Triparagon.  Note the 2 white wires circling around to the right side of the pic and laying atop the Trio A/P pitch trim servo are the 2 Autotrim wires that interface with the servo.

A shot of the right side Triparagon.  Again, after all the wires are in place I’ll do some major cable management on this rats nest before it flies.

Here’s the left side Triparagon.  As I mentioned before, I’m extremely pleased with how this turned out.  My next task will be to configure & mount the top cross shelf that will primarily hold the GRT GADAHRS, Trig TT22 Transponder and M760REM COM2 Radio. Also attached to the upper level will be 3 airspeed switches, the Gear & Canopy Warning module, the piezo warning buzzer, and possibly some pitot/static manifold blocks.  All these components I just mentioned above make up virtually the entire electrical system other than those components that will be mounted on the Instrument panel.

In the pic below of the left side Triparagon, you can see the Voltage Regulator in the upper left of the pic (again, mounted to F22, not Triparagon), the Endurance Buss (E-Bus/EB), TCW Smart Start module (SM), and the Autotrim components on the forward edge.  Note in the middle of the pic you can see the twisted red & black wires coming from the Atkinson pitch trim servo motor, terminated with small FastOn connectors to mount on the Autotrim relay (RP) tabs.

Here is a close up view of the Trio A/P Autotrim components: a bridge rectifier (AT) and a DPDT relay (RP).  Again, these components interface with the TCW Safety Trim box, the Atkinson pitch trim servo, and the Trio A/P pitch servo for the autotrim feature to operate.

You may note some chicken scratching writing on the wire labels (…at least you do now!). When I added the Triparagon as a Component Wire Location Identifier [N=nose, I=Instrument Panel, H=Hellhole, etc.] I not only changed these wire labels from A (Avionics Bay) to T (Triparagon), but also the end component 2-letter designator on a few items, including both of these autotrim components.  Since this wire label heat shrink is not exactly inexpensive, I made the decision to choose function over form here in an attempt to be both cost effective & pragmatic.  Especially on wire labels that honestly are rarely going to see the light of day once this plane is flying.  To put this in perspective, I’ve already printed almost 100 wire labels and have attached about 2/3rd of those.

One thing I didn’t show in this post was the unraveling and sorting out of the rats nest of nose gear & AEX wires that sat atop the NG30 cover.   I had zip tied them up to keep them out of the way while figuring out my rudder/brake pedal placement, and it looked like an unsolvable/untraceable mass of wires.  In reality, since I had labeled so many of the wires, after a good 10 min I had it all pretty much figured out and the wires in place, close to their final runs.  So, for the nose gear & AEX power, ground & warning signal wires, I heat-shrinked a bunch of the second labels in place, cut the wires close to their final length and crimped connectors onto a number of them as you can see with the AEX ground wire below that will terminate into the Avionics ground buss (G5).

I also went ahead and removed a good portion of the outer sheathing to the 3-wire cable coming from the Atkinson pitch trim servo positioning indicator.  The black wire of the group that I labeled and terminated with a FastOn connector will be grounded on the main panel ground buss (G4), while the red & white wires will tie together into one extension wire to feed an input into the GRT HXr to show trim positioning graphically on my EFIS.

I’ll be flying tomorrow, which will of course wipe out a good portion of the build day. Regardless, I’m estimating another 2-3 days to finish up this crazy wiring & Triparagon stuff before I get back onto installing the wheel pants (yes, yes!  I know!  You’ll believe it when you see it… ha!)