Nov 03, 2023     Installed updated pitch servo - (0.6 hour)       Category: Avionics

Re-installed the pitch servo in the aft fuselage, after it was replaced as part of a Garmin Service Bulletin.

  Nov 02, 2023     Autopilot servo replacement - (1.9 hours)       Category: Avionics

1. After receiving the updated Garmin autopilot servos that were replaced as part of a recent Service Bulletin, I prepped the new servos by installing the limit guards and recording the new unit's serial numbers.
2. Installed the new roll servo in the right wing.

  Oct 06, 2023     Removed autopilot servos for Service Bulletin - (0.6 hour)       Category: Avionics

Removed both the pitch and roll servos, in preparation for sending them to Garmin for a pre-emptive replacement.

  Dec 29, 2021     GPS antennas and coax connectors; ELT antenna - (1.5 hours)       Category: Avionics

1. Temporarily attached the GPS and XM antennas to their shelf.
2. Cut the three coax lines to the appropriate length. Attached TNC connectors to two of them, and prepped the third one for its BNC connector. (The BNC connectors I have in stock are not made for RG-400 cable, so the center conductor doesn't fit. I ordered a proper BNC connector from SteinAir.)
3. Repositioned the ELT antenna slightly to improve the clearance from the empennage fairing. [No photo.]

  Dec 28, 2021     GPS coax clamp - (1 hour)       Category: Avionics

Installed the first of the two Adel clamps that will support the GPS and XM antenna coax lines from the firewall passthrough to the antennas.

  Dec 01, 2021     Final GEA 24 wiring - (3 hours)       Category: Avionics

1. Today I completed the aft end of the last two wiring harnesses that will attach to the GEA 24 Engine interface module in the avionics "hell-hole." The final connections were the RPM sensor and the two fuel quantity indicator lines. Like all the connections in this area, these took quite a while to do, because I had to accomplish the connections while reaching through the narrow opening of the baggage door. Stripping wires, crimping tiny D-sub pins, inserting them into connectors, and assembling backshells are all MUCH more difficult when you can't get close to the work and you're bent over. My back needs a good night's rest.

2. I temporarily attached the GEA 24 to its mount, plugged in all four connectors, and did some wire lacing to clean things up. More lacing and tying up will be done later. Yes, I know the connector on the left is not seated all the way... :-)

  Oct 31, 2021     GPS mounting plate - (2.9 hours)       Category: Avionics

1. Fabricated the attach angles that will support the lower support arms of the GPS mount.
2. Installed floating nutplates for the GPS antennas.
3. Prepped and riveted all the plate components together.

  Oct 29, 2021     GPS mounting plate - (3 hours)       Category: Avionics

Continued building the new GPS mount. Got it clecoed to the firewall to check clearances from the standby alternator and oil filter.

  Oct 28, 2021     GPS mount fabrication - (4.4 hours)       Category: Avionics

Fabricated most of the new GPS mount that will be attached at the top of the firewall.

  Oct 13, 2021     GPS antenna tray test & final designs - (4.2 hours)       Category: Avionics

1. I got another idea for a GPS antenna mount tray that will be mounted on the firewall. I dug around through my crap bin and found an old ELT mounting plate that I think I can trim to size. I even has a stiffener riveted on the bottom of it.

2. After a lot of futzing around, I decided the old ELT mounting plate is not going to be suitable for the GPS antennas -- ironically, because of the stiffener on the bottom. It gets in the way, and I would have to drill it out, which would look junky. So I threw it back in the scrap pile and began constructing a new mounting plate from scratch.

  Mar 27, 2021     GPS and XM antenna coax - (4.7 hours)       Category: Avionics

1. Began installing the three RG-400 coax lines that will go to the GPS and SXM antennas on the firewall. First, I found a grommet that will work, then took a stock stainless-steel grommet plate and opened it up to accommodate a bundle of three coax wires.

2. Located and drilled the grommet cover plate onto the firewall in the upper-outboard corner of the baggage compartment. (I couldn't work out a good way to run the coaxes any other place without them being directly next to either the magneto leads or the fuel pump power wires, neither of which sounded like a good idea for antenna coax.) Located and drilled a matching hole in the bulkhead behind the instrument panel.

3. Installed both grommets and the grommet cover plate.

4. Located and drilled an attach point for an Adel clamp in the baggage compartment, on the upper fuselage gusset.

5. Installed a TNC angle connector on the end of a 7-foot coax.

6. Connected and ran the coax lines for the GTN 650 GPS antenna and the GDU 465 SXM radio.

7. Prepped coax for the GDU 465 GPS antenna.

  Mar 26, 2021     Fan test-fit; Cockpit lights; Pitot/static system - (3.5 hours)       Category: Avionics

1. Test-fit the avionics fan and its protective grill on the top skin. (The grill is flat black and made of aluminum, so it's pretty unobtrusive and sturdy. I think it will work well. I will remove the white sticker from the fan before I install it.)

2. Wired most of the rest of the cockpit lighting -- with the exception of the two strips lights, red and white, that will be attached under the glareshield. These will be connected to the lighting controller and their ground wires just before the top skin is finally riveted into place.

3. Closed up the swinging avionics access door in the baggage compartment. This is actually the very first time I have done this. My installation of all the components on it, and the wires going to and from it, was planned to let the door swing open and closed with no binding, no stress on the wires or connectors, and without interfering with any of the many components behind it -- and it was a total success! Very happy about how it all worked out.

4. Continued securing wires behind the instrument panel.

5. Connected the pitot and static lines to the AHRS and the G5. Capped some T-connectors with orange plugs that will indicate where to connect a pitot-static tester when that time comes every couple of years..(I'm not a fan of the lime-green T-connector, so I think it will be replaced soon.)

  Mar 22, 2021     Avionics fan - (1.9 hours)       Category: Avionics

1. Began planning and laying out the installation of the avionics cooling fan, otherwise known as my windshield defogger. :-) I match-drilled a long strip of aluminum to the top skin, then clecoed the strip to three bulkheads -- the instrument panel, the firewall, and the bulkhead between them. This established their relative positions when the skin is finally riveted on. Then I took some measurements behind the panel and determined the best place to mount the fan on the glareshield. It looks like the edge of the fan should be 1" forward of the row of rivets that attaches the top of the panel. So I marked the top skin appropriately, found the centerline, marked where the fan will go, marked and centerpunched a hole, measured the fan opening, and used a compass to scribe a circle around the hole in the skin. This will be what I cut out for the fan opening. There are also four screw holes I'll drill later. I also pulled off the protective blue plastic from the top skin.

2. Earlier in the day, I drove my prop governor to Aircraft Propeller Service in Lake Zurich, IL for a mini-overhaul, and to have its output adjusted down to 330 PSI for my Whirlwind prop. [Not counted in build time.]

  Mar 21, 2021     GPS antennas; VOR/ILS; AHRS; Autopilot, G3X audio; TOGA - (3.2 hours)       Category: Avionics

1. With the help of my friend Jim and his VOR/ILS test unit, we checked the VOR/LOC/GS antenna and coax, and managed to successfully display ILS data and VOR radial data on the PFD.

2. While I'm still waiting for my TNC connectors to arrive from Stein Air, I fabricated a work-around way to connect GPS antennas to the back of the GTN 650 and PFD. After one aborted attempt due to a shorted connection at one end of the coax, I got both receivers to work. The GTN was perfectly happy with my cobbled-together connections, and it got down to a 0.8 HDOP with 12 satellites, even inside my hangar! Not bad. The AHRS was also happy with the signal.

3. I raised the tail of the airplane to the level flight attitude, and performed the AHRS calibration. It was successful, and now I have pitch/roll info on the PFD, a horizon, flight director bars, and probably a bunch of other stuff, too.

4. I finally got every G3X unit online and a green checkmark on everything. There are still a couple of RS-232 ports that don't seem to be connected, but I'll figure that out later, after I do the magnetometer calibrations, and to do that I have to wait until the elevator and rudder are attached.. So I'll move on to something else for now, and assume that the compass configurations will go well, when I get to them.

5. I plugged in my headset and checked the audio outputs from the G3X system -- the audio alerts for approach minimums, the altitude alerter chime, etc. They all sounded great!

6. The final, crowing achievement was that I got the autopilot to turn on, and checked all the different modes displayed on the GMC autopilot controller and the PFD. It was a rush going to V/S mode, moving the thumbwheel, and watching the elevator pushrod move back and forth. Lastly, I pushed the TOGA button and watched the pitch servo move and the FP bars move up to 5 degrees nose-high on both the PFD and the G5. Yahoo!

  Mar 15, 2021     Avionics setups - (4.3 hours)       Category: Avionics

1. Began troubleshooting why my Nav 1 radio data was not showing on the G3X, nor did the Nav radio frequency display on the actual GTN 650. I pulled the unit to check for a bent pin, and lo and behold... It turns out there are four D-sub connectors on the back of the GTN. Sockets #1 through #3 are oriented with the wide side at the top ('right side up") but #4 is supposed to be mounted in the mounting plate upside down, with the wide side at the bottom. I could have looked at the back side of the radio and spotted this, but I'd built up the attach plate before I even took the radio out of the box. The plate also has an amorphous-shaped opening that can accept the socket either way. I fell for it, and mounted the socket upside down. When I pushed the radio in, it slightly bent all 9 pins. I straightened the pins, replaced the radio, and viola... I have a Nav radio. I updated it with new software, and now its seems fully ready to go -- except for one issue (see #3 below)..

2. Set up lighting in the G3X system so all units track the LC-50 lighting controller dimmer. (The only unit that does not integrate with the dimmers is the G5, but you can dim it with just one button press, so that's acceptable.

3. Worked on getting all the units to connect to each other. I had some success with two more of the RS-232 ports, and now most things are talking except for the G5 (although it is working on the CANBUS) the ADS-B data between the GTN and the transponder, and a few other things. Also, the actual VOR/ILS data still does not appear to be showing up on the G3X.

4. Got the G3X screen to once again display a split-screen by default, with the PFD on the left, maps on the right, with the engine info in a thin column on the far left side.

  Mar 14, 2021     Avionics setups and troubleshooting - (8.2 hours)       Category: Avionics

Jim and I spent a lot of time going through various systems, checking them out and/or getting them working:

1. We corrected a wiring error in the wing-root roll servo connector that was causing the roll servo to be invisible to the G3X. It's now working and online.
2. We checked the Rear cockpit LED maplight, which worked.
3. We tested the APRS power at the wing connector.
4. We fabricated a four-wire extension lead for the OAT probe from the left wing connector to the fuselage, so the AHRS would initialize.
5. We checked the wiring for the G3X config module and found I'd reversed two wires. We tried to remove the 26 AWG pins from the connector, but I didn't have a suitable tool to pull these undersized high-density pins (and neither did another friend of mine.) After numerous tries, and not wanting to damage the wires or pins, I eventually decided to cut, reverse, and splice the two tiny wires inside the connector. Now the config module works great. There was one minor glitch, however. When I powered up, the PFD went away, and now the unit seems to think it's an MFD only. This will require some more configuration research. I think the config module (which was a used one) had someone else's configuration on it. I may have to wipe it clean and start over.
6. I spent over three hours working my way through numerous setup screens on the GDU 465 and GTN 650, trying to get them to talk to each other appropriately. There are a maze of RS-232, A429, Garmin Data bus, Ethernet, MAPMX, and Connex interconnects, and they all have different requirements and settings. So far, I have had limited success with this effort. Lots more work ahead. (As an example of the issues, the GTN seems to be unable to locate its internal VOR / ILS (Nav) radio. It is grayed-out on every menu and screen.) I did get the engine instrument column to appear on the screen, however.

  Jan 13, 2021     Wiring, miscellaneous - (3 hours)       Category: Avionics

1. Ran power and ground wires for the oil pressure switch.

2. Connected several Canbus lines to their connectors.

3. Fabricated last remaining RS-232 connection for the GDU and GSU.

4. Decided to install a 3-conductor elevator trim position cable (because it's now or never). I connected it to a discrete input on the GEA 24. I think elevator trim position will be nice to have on the main EFIS screen.

  Jan 12, 2021     CANBUS and wing termination; cockpit lighting; rudder cables - (3.9 hours)       Category: Avionics

1. Finished fabricating all CANBUS wires for the G3X system. These will be installed into the connectors after the panel is installed in the airplane.
2. Fabricated a jumper connector for the wing-root autopilot connector so that I can fire up the G3X system while the wings are off the airplane.
3. Noodled around with the cockpit flood LED lights, trying to get an idea of where, exactly, they'll be mounted, and how their wires will be routed.
4. Secured the rudder cable pass-through tubes under the forward floor area.

  Jan 11, 2021     Wiring, miscellaneous - (3.5 hours)       Category: Avionics

1. Finished fabricating the power/CANBUS harness for the GEA 24.
2. Ran the final ground wires for the various Garmin LRUs.
3. Bundled the first batch of ground wires into a harness in the avionics hell-hole, and secured it. Changed out several supporting Adel claps to the proper size.

  Jan 10, 2021     Wiring, avionics - (3.3 hours)       Category: Avionics

Continued fabricating Garmin CANBUS and RS-232 lines, and pinning them into their connectors.

  Jan 09, 2021     Wiring, avionics - (1.7 hours) Category: Avionics

Continued fabricating Garmin avionics harnesses. [No photo]

  Jan 08, 2021     Wiring, avionics - (4.2 hours)       Category: Avionics

Continued fabricating wiring harnesses for the Garmin avionics.

  Jan 08, 2021     Fire extinguisher; Wiring panel avionics - (3.9 hours)       Category: Avionics

1. Attached fire extinguisher bracket to aft face of front seat.
2. Installed configuration module in connector housing of GDU 465 connnector housing and crimped on its pins.
3. Labeled connectors, shells and cover plates with their identities, so I don't mix anything up while I'm wiring.
4. Accomplished first interconnects of the panel avionics: Wired multiple interconnects between GMA 245, GTN 650, and GTR 20.

  Jan 05, 2021     Wiring, miscellaneous - (4.5 hours)       Category: Avionics

1. Prepared and assembled all D-sub connectors for the GTN650, GMC507, GMA245, and GDU465 (including configuration module).
2. Crimped pins onto connector for GTN fan.
3. Ran fuselage part of power and ground for autopilot roll servo. Accomplished splice of power leads for various autopilot components for autopilot master switch.
4. Fabricated the wing root connector for the autopilot roll servo. Used a non-Garmin shell with a run-around ground drain setup to keep the integrity of the Canbus shield
5. Researched various interconnects for the G3X system, and I have some questions about parts of the diagrams I'm using. Will investigate.

  Jan 03, 2021     Transponder installation - (3.3 hours)       Category: Avionics

1. Checked all clearance issues with transponder by installing baggage floor and baggage wall. The clearances are tight (1/8”) but it will work fine.
2. Tightened backplate to rack.
3. Finalized positioning of wiring harness where it exits the rack connector. Added anti-chafe plastic tubing around transponder harness so rudder cable has no chance to contact it.
4. Formed all transponder cables into a nice harness. Added Adel clamps along under-floor support structure.
5. Finalized bundling of ELT harness wires.
6. Fabricated transponder coax cable. Connected one BNC connector, then climbed in the fuselage, routed the cable, and connected the other BNC. Routed cable to stay away from rudder cables and other hazards. Secured cable with various kinds of clamps.

Other than sliding the ELT and transponder into their racks at the appropriate times, and connecting the elevator pushrod, I believe there is nothing left to do behind the aft baggage bulkhead. Hooray!

  Dec 28, 2020     Pitch servo CANBUS node and connector - (1 hour)       Category: Avionics

1. Finished fabricating the CANBUS node for the autopilot pitch servo.
2. Assembled connector shell.
3. Attached connector to servo and tied up harness.

  Dec 24, 2020     Pitch servo and CANBUS - (2.1 hours)       Category: Avionics

1. Installed autopilot pitch servo. (Left the elevator bellcrank detached for now.)
2. Mostly wired the pitch servo connector. (All that's left is to solder the CANBUS nodes and pin them into the connector.)

  Dec 17, 2020     Pitot line - (1.4 hours)       Category: Avionics

1. Installed pitot line from L wing root to the location of the ADAHRS.
2. Cleaned up wiring log and diagrams.
3. Researched various issues..

  Dec 14, 2020     Avionics power distro buses; GMU 11 harness. - (4 hours)       Category: Avionics

1. Located, drilled, and attached the all-important avionics power distribution buses. Ran the primary and secondary power feeds for these buses and attached them.

2. Wired harness for GMU 11 magnetometer.

3. Removed ELT for more access room. Crawled into my least favorite place, the aft tailcone, and installed the CANBUS terminator, followed by the harness connector. Had to drill a new hole for an Adel clamp on the shelf. (To prevent magnetic interference, I used an aluminum AN3 bolt, washer, and nyloc nut to fasten it.) Put sheathing on the harness, then ran the harness to an under-floor location where the CANBUS will split off and go to the pitch servo.

  Nov 03, 2020     R Wing CANBUS connector, R wing wires. - (3 hours)       Category: Avionics

1. Installed an overwrap on roll servo lines, from the root rib to the connector.
2. Prepped all wires and Installed a female Garmin 9-pin D-sub connector at the wing root. I will match this with a male connector on the fuselage.
3. Secured all wire runs inside the R wing.
4. Final-installed the FCP headset jacks and began working the wires into place under the nearby cover plate.

  Nov 02, 2020     FCP headset jacks; GSA 28 roll servo wiring - (3 hours)       Category: Avionics

1. Wired and installed the FCP headset jacks.
2. Ran wires for servo power through the R wing.
3. Installed my first Garmin connector on the servo wires. Used a solder sleeve for the backshell ground (I love those things!) The ground is still not connected because I don't have any short 8-32 screws yet.

  Nov 01, 2020     Headphone jacks; Main avionics rack - (2.3 hours)       Category: Avionics

1. Began installing the pilot headphone/mic jacks. Drilled another hole for the wires to pass from under the right armrest up to the jacks. Enlarged all four holes to 7/16" to accommodate the isolating washers. Wired the RCP jacks.
2. Began installing the avionics racks for the GTN 650 GPS, the GNC 507 Autopilot and GMA 245 Audio panel.

  Oct 29, 2020     TOGA switch; Cockpit dimmers; Antenna coax. - (4.1 hours)       Category: Avionics

1. Created a wire harness with a 4-pin mini-Molex connector and soldered it to the TOGA switch. (On the few switches with solder connections, I like to make them easily removable for servicing purposes, in case a solder joint ever goes bad. It's FAR easier to re-solder a connection sitting on my workbench than it is while lying upside down under the panel.)
2. Installed the TOGA switch in the panel.
3. Made another wire harness with a 6-pin mini-Molex connector for the cockpit dimmers. (Again, these are all solder-joints.) Also fabricated six daisy-chain wires for the power and grounds to each dimmer. Soldered the harness leads and the daisy-chain wires. Coated all connections with insulator liquid. Secured the harness to the adjacent switch for strain relief.
4. Connected the coax cable for Com 2 to the antenna and began running the coax up behind the panel, where Com 2 is located (no photo)..

  Oct 28, 2020     Various connectors and wire runs. - (2.4 hours)       Category: Avionics

1. Began running the CANBUS wire through the right wing. Positioned it near the autopilot servo. The rest of the autopilot wires and the connector will be next. I also researched how to make a CANBUS connection at the wing root. (It looks like I will be using a shielded, metal DB-9 connector.)
2. Installed a single-pin Seal-All connector on the APRS power lead at the right wing root.
3. Began running the coax cable for the Com 1 antenna on the belly.
4. Began assembling the Com 2 coax.

  Oct 24, 2020     Com antenna installations - (1.6 hours)       Category: Avionics

Installed both Com antennas on the belly of the aircraft. Used special industrial RTV to make a good seal under each.

  May 04, 2020     Instrument panel; starter switch wiring bus. - (4.4 hours)       Category: Avionics

1. Printed out full-size prints of the instrument panel and Circuit Breaker panel, and attached them to the actual panels in the airplane. Worked out some more slight changes to the location and labeling of a few switches with my panel design guru, Joe. We are now to the stage where we're moving items 1/4" or less, so I think we're pretty close to finalizing everything.

2. Located, drilled and installed the terminal strip that will interconnect the stick-mounted starter switch, the backup starter switch, and the starter relay. This terminal block is located under the front seat, close to where the stick wires come through the spar.

  Apr 28, 2020     Autopilot pitch servo; transponder coax - (4.2 hours)       Category: Avionics

1. Drilled out old TruTrak pitch servo in the aft fuselage.
2. Prepped the new Garmin attach angles to my specifications by cleaning them up and polishing the edges.
3. Since match-drilling the new servo attach angles from the old ones was not possible, and neither was match-drilling them from the holes in the fuselage, I transferred the measurements of the hole locations to the new angles, and drilled the holes. They came out close enough for me.
4. Removed the elevator bellcrank to a). check it for conformity to Garmin's measurements, b). inspect the bellcrank bearing, c). install a Garmin-required washer between the sides of the bellcrank, and d). ream the servo arm hole to size #12.
5. Clecoed the new mounting angles in place to check the fit. I had to remove them and file down a bit more of the nearby bulkhead to get the angles to fit, just as Garmin said I would probably have to do.
6. While I was in there, I drilled a pass-through hole in the bulkhead for the transponder antenna coax, and installed a snap-bushing.
7. Assembled the servo pushrod to Garmin specs, and began laying out the servo attach hardware and rivets for tomorrow's installation.

When working in the aft fuselage of a completed RV-8 fuselage (my least-favorite place), and because I don't want to have to climb out and go over to my toolbox any more times than necessary, I always load up a rolling cart with every possible tool I think I will need to do the job. And then I add a few more that I cannot imagine I would need. The number of tools in the cart, when I insert myself into the airplane, is "X." I have noticed that, no matter what number "X" is, the number of tools required to complete the job is always between X+1 and X+5. This is Buck's Theorem. Feel free to validate it, at will, in your own airplane project.

  Apr 27, 2020     Autopilot roll servo - (3 hours)       Category: Avionics

1. I have been waffling about where I wanted to install the Garmin GSA 28 roll servo. There is already a mount in the fuselage, under the floor, for my old Tru-Trak servo, and I could probably make it work. But it would require some cutting, filing, and amateur engineering. And there's no guarantee I wouldn't run into some kind of unexpected problems later. So I decided to just go with the Garmin standard RV-8 location for the servo -- in the right wing, adjacent (and attached to) the aileron bellcrank. In the end, it was totally painless and easy to do, and I'm glad I put it there. And along the way, I even figured out how I am going to run the wire harness without too much aggravation. It was a good day!

2. Prepped autopilot roll servo installation by assembling the pushrod arm and attaching the servo to the mounting angles and aft mounting arm.

3. Located and drilled the #11 hole in the aileron bellcrank.

4. Installed the servo and mounts in the wing. Torqued all but five of the attach bolts for the aileron pushrods and bellcrank, just so I have some flexibility to adjust things later.

  Apr 24, 2020     Power Stabilizer installation - (0.9 hour)       Category: Avionics

Drilled mounting holes for the TCW Intelligent Power Stabilizer(IPS) unit on the front side of the right gear tower -- which is pretty much the only place left for it to go. Installed the unit.

  Apr 20, 2020     Left lower panel; RCP vent line; flap switch; annunciator; terminal block template - (3.2 hours)       Category: Avionics

1. Cut out mounting holes in the left lower subpanel for the CO Guardian detector and the front cockpit seat heat switch. Cut and conuntersunk holes for the attachment nutplates. Notched the hole for the seat heat switch. Test-fit both items. Sanded, cleaned, and primed the panel. (The left nutplate orientation looks psychotic, but that's what I had to do to make it work!)

2. Installed caterpillar grommet in under-floor pass-through hole, then installed the 2-foot section of scat tube connecting the right wing flange to the rear cockpit vent.

3. Located, drilled and installed a snap bushing in the small hole in the gear tower where the wires for the flap switch will run.

4. Worked on assembling the LED light assemblies in the annunciator panel.

5. Made a drill template for the half-dozen terminal strips that will be installed in various locations in the fuselage.

  Apr 19, 2020     Panel design; annunciator box install; static line - (5 hours)       Category: Avionics

1. Worked with Joe on numerous small details about the instrument panel design, tweaking the location of everything and some of the labels. I think we just about have it done.

2. Took measurements of all CANBUS, RS232, and A439 runs, so I can make sure Joe builds the harnesses correctly. I added 24" to the wiring that will go to the back of the GDU 465 main screen, so it can be removed easily. In the RV-8, that big EFIS hole is one of only two ways to access a lot of the stuff behind the panel.

3. Figured out a location to mount my homemade annunciator "black box" I built a few years ago. When I built it, I must admit I didn't really consider where it would go, or how it would be mounted. But today I figured out those details, and now it lives in between the two alternator controllers. Because of the weird case I put it in, I had to mount it with 1/4" standoffs.

4. Drilled another pass-through hole in the left gear tower to accommodate the static line, and routed it up to where it will split off for the Alternate Static Air valve. This hole will also be used for at least six wires from the aft fuselage.

  Apr 18, 2020     Electrical / avionics planning - (7.2 hours)       Category: Avionics

1. Spent much of the day planning the location and mounting schemes for almost all of the electrical items in the airplane. Assembled the entire avionics rack and temporarily installed it to check the fit and begin some detailed wire planning. I had to do some serious on-the-fly engineering on my annunciator adapter box in order to figure out how to mount it.

2. Continued working on instrument panel and subpanel planning with my awesome panel guy, Joe. He is finalizing the cut files so I can get the panels water-jetted.

  Apr 17, 2020     Avionics rack - assembly; pitot/static; transponder coax - (5 hours)       Category: Avionics

1. Sanded and repainted the lower avionics shelf after a painting fiasco caused by me. (Not pictured).
2. Installed T-connectors to the GSU 26 ADAHRS, One side will be from the pitot/static sources, and the other will go to the Garmin G5.
3. Crawled into the aft fuselage (my least-favorite place), removed the old RG-400 transponder coax, and replaced it with the new, much better and shorter coax. I left one end without a BNC connector until I see exactly how long the cable needs to be.
4. Re-designed a bit of the Main electrical bus to minimize wire runs. Essentially, I am "ganging" together the rows of C/Bs in a more efficient way.

  Apr 16, 2020     Avionics rack; transponder coax; avionics hellhole wall - (3.4 hours)       Category: Avionics

1. Drilled the lower shelf of the main avionics rack to the aircraft structure and checked all clearances and assembly considerations. I decided that installing nutplates on the bottom side of the aircraft's z-channel would be way too time-consuming because of the proposed location, so I will just use #8 screws and nyloc nuts to attach the forward edge of the shelf.

2. Installed nutplates on the support bars and aft attach angle.

3. Sanded, primed, and painted the lower shelf. (Not shown)

4. Measured the distance between the transponder antenna and transponder, then cut a 30" length of my nice new coax cable. Prepped both ends, then installed a BNC connector on one end. The other end will get a connector after I route the cable. (By the way, the coax I'm using is a super-duper MILSPEC low-loss coax called Heliax/Commscope FSJ1-50A Superflex. It's fairly stiff but very flexible -- more so than RG-400 -- and it keeps whatever bends you put into it, which is great when you install it It's really high-quality, commercial stuff, having essentially has no loss over the short runs you'll find in an RV-sized airplane. Best of all, the process of installing the BNC connectors is stupid-easy compared to the laborious process you have to use with normal coax cable. I love this stuff!

5. When I moved to my new house a few years ago, somehow I lost the sidewall of the lower baggage compartment. I have no idea where it went, but it isn't with the rest of the similar parts. So today, I got its replacement from Vans. If you ever find a forlorn baggage wall out there in the world, it might be mine.

6. Finished installing the forward GEA24 rack into the floor of the hellhole. As I suspected, I had to use a #6 self-tapping screw on the right-forward hole, The rack is now nice and secure. (Not shown).

  Apr 15, 2020     Avionics rack - construction and installation - (2.3 hours)       Category: Avionics

Installed all nutplates on the upper deck of the main avionics rack and the forward avionics rack. Riveted the stiffener to the GEA-24 mounting plate. I decided to paint the plates to hide the all rivets. This will make it easier to find the screw holes during later maintenance.

Installed the attach bars to the floor of the forward avionics bay. One blind rivet is impossible to install using the pullers I have, so I may have to use a screw there.

  Apr 15, 2020     AP servo stops; Avionics rack; Essential bus relay - (1.5 hours)       Category: Avionics

1. Attached the safety stops to the Garmin autopilot servos. Evaluated whether I can use the existing Tru-Track attach angle for my pitch servo. The answer is no, so I ordered the Garmin attach kit.

2. Finished painting all but one component of the main and forward avionics racks.

3. Attached the Essential bus relay to the forward bulkhead, next to the E-Bus.

  Apr 13, 2020     Avionics racks - construction - (4.1 hours)       Category: Avionics

I had already written-off the idea of bending my support bars a few degrees, but I decided to try a little experiment. I fabricated another rack support bar out of 0.090" aluminum, built the same size as the three in my rack. Then I tried bending it with my silly little bending brake, and it WORKED! So I ganged all three of the real supports with tape, and bent them all at once, just to make sure they were identical. It worked great. Reinstalling everything verified that the baseplate and the support legs will now sit flush on their respective mounting points. With the rack clamped in place, I drilled some initial #40 attach holes into the airplane structure and got the rack clecoed. I'd been wondering how stiff the rack would be, and it seems like it will work very well, but the lower plate had a slight bit of flex along the spanwise axis, so I fabricated a stiffener to take care of that. Primed and painted most of the remaining components of the forward baggage bay rack.

  Apr 12, 2020     Avionics rack - construction and test-fitting - (3.5 hours)       Category: Avionics

Continued building the main avionics rack behind the panel. The main structure is now mostly complete, so today I drilled and countersunk most of the rest of the nutplate holes. Primed most parts. Clamped the base plate and supports into the airplane to see what the best way to attach it would be. It turns out the flange of the forward cross-brace sits at a slightly different angle from the z-channel just forward of it. This means that the baseplate does not sit flat (see photo #2). I began to figure out how I'll correct for this. My first thought was to bend the three supports a few degrees, but they are made of 0.090" aluminum, and my bending brake is only capable of handling 0,040". Next, I considered bending the baseplate just aft of the support angle, but this would mis-align several of the threaded standoffs between the lower and upper levels. Finally, I researched screw shims and tapered washers at McMaster-Carr. I found a few items that might work, so I ordered them. We'll see.

  Apr 11, 2020     Avionics rack - forward bay and main rack - (3.4 hours)       Category: Avionics

Continued fabricating the forward avionics rack that will hold the GEA-24 engine interface box. Finished building the various parts. Clamped everything together to check the fit and placement. Drilled all holes and countersunk. Installed some of the nutplates. Primed the first few parts.

Continued building the main rack that will be mounted behind the instrument panel. (No photos).

  Apr 10, 2020     Avionics rack construction - (4.1 hours)       Category: Avionics

1. Continued fabricating the avionics rack. Began by clamping the two shelves together and match-drilling the standoff holes so they will match perfectly. Installed the standoffs and test-fit all the components so verify fit. (I'm glad I did this, because I actually had to move the Com radio about 1/32" to ensure clearance from one of the standoffs.) Verified all the D-sub and coax connectors will have adequate room. Continued working on the exact method this rack will be mounted into the airplane. Cut out stiffeners from stock angle. These will be riveted to the underside of the shelves. Marked, match-drilled, deburred and countersunk both the shelves for the stiffeners.

2. Continued constructing the mount for the GEA-24 that will be located in the forward avionics hellhole.

  Apr 09, 2020     Avionics rack - mockup and initial construction - (7.5 hours)       Category: Avionics

Continued mocking up and designing the avionics rack behind the panel. It is now two layers instead of three, and the GEA-24 engine interface adapter has now been moved to the forward avionics "hell-hole" forward of the right gear tower. This will minimize the number of wire runs that will need to go into the minimal space behind the panel, and will shorten the wire runs from the various engine sensors. I also moved the LC-50 cockpit lighting controller to the top shelf of the rack.

Used foam board to simulate both layers, and moved the LRUs around like Tetris blocks until all the clearance issues were resolved. Then I spent some time working out a way to mount the rack to the aircraft structure, planned how to make it all removable and maintainable, and planned where all the standoffs will go, so the structure will not interfere with the cable runs. The whole process was very iterative, and I spent over 4 hours on just these tasks. Next, I transferred the dimensions from the foamboard to some sheets of 0.040 and cut them out, and filed and sanded the edges

I also designed a mount for the GEA-24 and cut out the aluminum for it.

  Apr 08, 2020     Avionics rack - beginning mockup - (1.6 hours)       Category: Avionics

I am beginning to puzzle out the exact locations for all the Garmin LRUs (Line Replaceable Units) that will be installed. My initial plan will be to build a three-tiered avionics rack behind the panel that will allow for reasonable access to the LRUs when the main EFIS screen is pulled out of the panel. On the bottom layer will be the remote GTR-20 (Com 2) radio. Above that will be the GEA 24 Engine Interface Module and the GAD 29 Interface Adapter. Finally, up top, will be the GSU 25 ADAHRS. I need to build a sturdy rack that doesn't flex, but can be disassembled with a socket wrench or a hex driver through an 8" x 10" hole. I like this kind of challenge. I began mocking up the structure using foam board, just to check clearances and figure out how it would attach to the airplane.

  Feb 10, 2020     Transponder mount - (0.8 hour)       Category: Avionics

Completed construction of aft transponder mount. Painted mounting plate. Attached angles and rack.

  Feb 08, 2020     Transponder mount - (3.9 hours)       Category: Avionics

Finished building the transponder mount, only to discover that there were several problems with the installation. Ended up remaking the mounting plate so that the transponder will be positioned horizontally, rather than vertically, underneath the hat shelf of the baggage compartment, Because of the lip on the aft edge of the left sidewall piece, I had to shim up the front side of the transponder mount about 1/4", effectively tilting it inboard a bit. I also moved the mounting plate aft just a bit. Drilled all the angle attachment holes, test-fit the mount, then deburred, sanded, and primed the major pieces.

  Feb 06, 2020     Transponder mount - (2.5 hours)       Category: Avionics

Cut an approximate-sized mounting plate from 0.050" aluminum, then fabricated four angle attach points that will attach the transponder tray. I laid out the original strobe mounting plate, and transferred its nine original screw locations onto the new plate. Next, after a bit of pondering and taking measurements in the aft fuselage, I traced the outline of the transponder tray into what should be the best location on the mounting plate--one that will allow access to the mounting screws and also give enough room for the wiring harness.

  Feb 01, 2020     Transponder mount - (1.1 hours)       Category: Avionics

Began doing "on-site engineering" to figure out how to adapt an old strobe pack mounting plate into a mount for the remote GTX 45R transponder. The existing plate is just a bit too small, and would present some pretty unreasonable construction challenges, so in the interest of saving time, I'm just going to make a new mounting plate out of some 0.050" 2024-T3,

  Jan 07, 2020     Installed new Garmin OAT probe - (1.1 hours)       Category: Avionics

Installed new GTP 59 OAT probe in left wing. Ran new wire to wing root bay. This wire will make the rest of its run without going through the wing root connector, so it will remain coiled up inside the last bay for a while.

  Jan 06, 2020     New OAT probe - (2.5 hours)       Category: Avionics

Removed old Grand Rapids OAT probe and wiring from left wing. Fabricated adapter bushing to fit new Garmin GTP-59 OAT probe into oversized hole.

  Jan 28, 2015     Annunciator panel - (.8 hour)       Category: Avionics

I assembled all 9 lamp assemblies for the annunciator panel, using thick CA glue to secure the white LED shroud pieces inside, and thin CA glue to secure the end caps. Three of the lamps need additional components across their leads, and I tried fitting these inside the housings, but there wasn't quite enough room. Therefore, they will be soldered onto the leads externally once the glue dries.

  Jan 27, 2015     Annunciator panel - (1.5 hours)       Category: Avionics

I began the process of installing the new and improved LEDs in their housings. The bases have new holes drilled in them, but they need to be held in a very close-tolerance position inside the housings. Using a test assembly as a template, I glued each LED into its base. Once these dry, the LEDs will be inserted into the white collars, sticking out about 0.5 to 1.0 mm. (photo 2 below). Then they will be inserted into the black lens housings. The bases will be glued into the housings to complete the basic assemblies. After than, I'll start on the labels.

Photo 1: The LEDs: 6 blue, 2 red, and 1 yellow, along with the glue I'm using.

[Superseded.]

  Jan 26, 2015     Annunciator panel - (2.2 hours)       Category: Avionics

I finished assembling the circuit box for the annunciator panel, and began modifying the lamp assemblies. The new LEDs I'll be using are much brighter that the original ones, and their flat faces distribute light more evenly across the lenses. I trimmed off the old solder lugs and drilled two new holes in each of the bases for the LED leads to stick out.

[Superseded.]

  Jan 20, 2015     Annunciator panel resistor box - (6.5 hours)       Category: Avionics

This entry represents a couple of days of work on an electrical project that has probably taken far longer than it should have. (But I just love engineering projects like these -- I can't help myself!)

1. Decided to add a second D-sub connector to the resistor box for the annunciator light panel, instead of simply running the wires out the side of the box. Cut the hole and attached the new connector.

2. Finished soldering the various resistors onto the PC board for the annunciator light panel, cut 18 lengths of 22AWG Tefzel wire, soldered one end of each to the appropriate pad on the board, crimped D-sub pins on the other ends, and wired the connectors. You'll notice in Photo 2 that the resistors are staggered up and down because of the tight spacing between slots.

[Superseded.]

  Jan 13, 2015     Traffic watch antenna - (.2 hour)       Category: Avionics

Located and drilled the 5/8" hole in the bottom of the gear tower where the coaxial cable for the Monroy ATD-300 traffic watch unit will pass through.

[Superseded.]

  Jan 12, 2015     Annunciator box; Traffic watch antenna; misc. - (2.4 hours)       Category: Avionics

Tonight I made some good progress on the small circuit box that will feed my homemade annunciator panel with the appropriate signals. I sourced a small Radio Shack PC board and a plastic project box, then scrounged up some 4-40 screws, threaded standoffs, washers grommets, and a pair of 15-pin D-sub connectors. I drilled and filed the large hole for the connector, drilled holes for the wires to pass through one end of the box, and drilled holes for the PC board mounting studs. Tomorrow, I'll start assembling the components to the PC board and wiring them to the connector. [Superseded.]

Next, I located a good spot on the right landing gear attachment cover for a small, transponder-type antenna. This antenna will actually be for the Monroy ATD-300 traffic watch unit. Its installation manual specifies that the antenna is best located on the belly, forward of the wing. On a QB RV-8, this is a tall order, since there is no access to the inside of the skin anywhere forward of the spar. The two places I would have liked to install it would be very difficult to accomplish. So I went with the obvious and easy spot. With about 6" of service length built into the RG-58 coax, the cover will be easily removable when it comes time for checking the gear bolt torques. [Superseded.]

  Jan 08, 2015     Annunciator LED testing - (2.5 hours)       Category: Avionics

This entry covers several days of testing I've been doing on the LED lights that will be part of the custom annunciator panel I'm building. I changed out the stock LEDs in the MPJA enclosures with higher-brightness ones. My concern was the range of brightness. I want these lights adjustable so they are really bright in the daytime, and can be dimmed significantly at night. So, with the help of a decade resistance box and a selection of various potentiometers, I figured out a combination of dropping resistors and a pot that will give a decent range. The dropping resistors are 150 ohm, and the pot is a 5K linear taper. I ops-tested the setup for 24 hours at 13.8V and "full-bright," just to make sure the LED would hold up, and the resistor would not get too hot. It seems fine.

Am I a Full Bright scholar now?

Testing... testing... is this thing on?

  Dec 23, 2014     Dynon compass D3 service update - (.3 hour)       Category: Avionics

A few years ago, Dynon announced a modification that needs to be done to the D-10A's compass. Today I accomplished the mod. It's pretty simple and straightforward.

The procedure has you take off the cover the compass module, locate D3, a tiny surface-mounted diode, and carefully clip it off the circuit board.

This mod was needed to correct an issue with the accuracy of some of their Outside Air Temperature (OAT) probes.

[Superseded.]

  Dec 12, 2014     R wingtip APRS transmitter - (2.3 hours)       Category: Avionics

Tonight I installed the APRS radio system in the right wingtip. I laid out all the components and finalized the wiring runs to minimize RF interference, glassed-in the VHF antenna, and made a wooden GPS antenna mount out of glued pieces of shim stock and bonded it in to the wingtip, After I take the APRS unit home and verify that it's programmed correctly, it will be final-installed.

  Nov 29, 2014     Marker beacon antenna - (3.3 hours)       Category: Avionics

I had originally planned to use a pre-made Archer SA-009 marker beacon antenna, which is nothing more than a 40" length of copper tape and some hardware. Today, after looking at it, I decided to make my own. I got a 46" length of RG-400 coax, and stripped 40" of the shield layer from it, then crimpled on a BNC connector. Then I fabricated a small angle bracket for a BNC female-to-female pass-through connector. This bracket will be fiberglassed into the tip, and the existing coax wire in the wing will get a connector. This way, I can easily remove the wingtip.

By the way, stripping 40" of RG-400 is a BEAR. It took me far longer than I expected, even using a coax stripper tool. I had to go about 1/2" inch at a time.

  Jan 30, 2011     Autopilot pitch servo (v.1) - (.8 hour)       Category: Avionics

Now that I can crawl back into the fuselage, I finished the installation of the autopilot pitch servo by safety-wiring its forward attach bolt to another AN3H-3A bolt I attached to the front of the case.

Photo: Yeah, I know the torque seal enamel is supposed to be at the BASE of the nut. I'll fix it.

[Superseded,]

  Dec 07, 2010     Avionics rack - (1.0 hour)       Category: Avionics

Today I continued assembling the recently anodized avionics rack and fitting the various boxes to it. Each of the small boxes (such as the Power Stabilizer shown below, on the right side of the photo) will be mounted to an integral attach plate that will then be attached to the rails with screws and nutplates. The backup battery, on the left, will bolt directly to the rails because of the placement of its mounting holes.

  Dec 05, 2010     Avionics ground bus (v.4) - (2.5 hours) Category: Avionics

I finalized the design of my latest, greatest avionics ground bus (version 4). After some final development, I think this one will be successful enough to actually offer it to the homebuilding marketplace as a finished product. The new circuit boards and D-sub sockets have been ordered, and I have sourced a nice case to use.

Version 4 uses a 37-pin connector instead of a 25-pin one. This increased the size of the unit slightly. I also significantly improved the PC board design, and made some other major improvements.

  Dec 01, 2010     Avionics rack - (1.7 hours)       Category: Avionics

I got a bunch of parts back from the anodizer today, including the components of the avionics "black-box" rack. They were anodized with the same UV-resistant process that was used on the canopy rails. I spent some time riveting on the nutplates and beginning to assemble the rack. It will really look great -- too bad it'll be buried down in the avionics bay...

[Superseded.]

  Nov 26, 2010     Avionics ground bus (v.3) - (1.5 hours)       Category: Avionics

I received the first prototype custom printed circuit (PC) board from ExpressPCB today. (Actually, I got four of them, which is their minimum order.) It looks good!

The PC board itself is the same width as the socket, so it'll fit inside my small enclosure just fine. My plan is that the PC board will not need any support at all after the socket and lead wires are soldered to it. It will just hang vertically from the bottom of the socket. This will greatly reduce the parts count and keep the unit as simple as possible. As long as the main lead wires are properly strain-relieved, this should be a very tough and foolproof ground bus.

I soldered a female socket to the board, did a continuity check, plugged in an empty male socket, and test-fit a few male pins. Everything checks out great. Final assembly of the unit will probably be early next week.

[UPDATE: This version of the Ground Bus design was updated later. The individual narrow traces were replaced by one large trace that encompassed all of the connector pins and the ground leads pads.]

Photo 1: The female D-sub socket, mounted to the PC board.
Photo 2: Bottom view, showing the grounding traces.
Photo 3: Another view. Two 14 AWG wires will be soldered to the pads at bottom.

[Superseded.]

  Nov 21, 2010     Avionics ground bus (v.3) - (4.5 hours)       Category: Avionics

Even though Version 2 of the avionics ground bus was a big step up from Version 1, I found that I still had both a philosophical problem with its construction, and a mechanical one.

Here's the first problem: The main ground wires (the ones that run from this bus to the firewall ground block) are still soldered to the D-sub connector pins. Because of the limited visibility and access to the backside of the pins (see previous entry), it's tough to know if these connections were made well enough to survive a long life in an airplane. The soldering was a bit tricky to do, and I just can't risk the slightest question in my mind about whether these connections will be be reliable long-term. If they were to fail, my entire avionics package would fail. Bottom line: Soldering ganged wires across the back of a socket that's not designed for this application just seems a bit... chintzy. Especially for an IFR airplane.

So today, I taught myself to use some design software and used it to design a printed circuit board (PCB) that will solve this problem. The D-sub socket will be soldered to the PCB, and the connections will be ganged together by the foil traces on the PCB. The ground wires will then be soldered to pads on the board and strain-relieved inside the case. This should be a foolproof way to ensure the quality of these critical connections. I sent my finished design to a prototyping company for rapid manufacturing, and I should be receiving a prototype custom board in a few days. If it works well for me, I may offer the boards for sale, either as a kit or a complete unit.

Second issue: Version 2's pins will not click into place like Version 1's, since Version 2 deleted the male socket entirely. In other words, the pins need to click into a female socket mechanically, or they'll just pull out. Duh. I'll go back to using two sockets mated together.

  Nov 18, 2010     Avionics ground bus (v.2) - (2.5 hours)       Category: Avionics

In the last few days, something began bothering me about Version 1 of my avionics ground bus. The 25-pin D-sub connector I'd used was the "solder cup" style, and the two 14-gauge wires I'd soldered to the back were not really mechanically secure before soldering. Mechanical security of a joint is one of the primary rules of soldering (especially for a connection that will be so critical, and subject to vibration, as this one). Honestly, it probably would have been fine, but I just can't compromise -- not with an avionics installation I will trust with my life someday.

So today I re-built the whole thing, this time using a different style of D-sub connector I got from a local electronics store. This one is a female 90-degree PC-board mount. Its long leads make it easy to curl the pins around the ground wires before soldering.

(UPDATE: Although this design might be adequate, I will be re-designing the avionics ground bus yet again. Version 3 will feature the D-sub socket soldered to a custom PC board inside the housing. The two 14 AWG ground wires will be soldered to the PC board. More in the next entry...)

[Superseded.]

  Nov 13, 2010     Autopilot pitch servo (v.1) - (2.6 hours)       Category: Avionics

I had enough time to begin installing the autopilot pitch servo today. This autopilot is a TruTrak Digiflight II VSVG. (Note: I believe the design of the servo mount has been superseded over the past few years -- so if you're looking at these pictures and don't recognize the installation rails, that's probably why.)

The servo went on fine, but in the process of tightening the two bolts, I noticed that the integral wiring harness that runs between the servo and the connector housing was rubbing on the nearby bulkhead. So the servo came back out, and I zip-tied a length of split, thick-wall tubing to the harness, then re-installed it.

I started safety-wiring the two attach bolts, but discovered that I'll need a third AN3-3 with a drilled head. I'll have to buy one from our FBO next week.

The safety wire in the third photo will run up to the new bolt, which will be screwed into the upper forward corner of the autopilot housing (just about where the wire passes by in the photo).

Photo 1: A closeup of the servo wires rubbing on the bulkhead.
Photo 2: Wiring is now protected with thick-wall plastic tubing.
Photo 3: Servo has been attached and being safety-wiring is in progress.

[Superseded.]

  Jul 20, 2009     AHRS mount (v.1) - (2.0 hours)       Category: Avionics

I began fabricating a mounting shelf for the AHRS that will reside behind the instrument panel. In the RV-8, space behind the panel is minimal, and this location is just about the only place I can think of that will work. I cut and bent up some 0.040" sheet, and clamped some angle to it to make a strong little platform. It will be attached to the adjacent cross-braces with as few rivets as possible. [Superseded.]

  Mar 31, 2009     EIS test-fit - (.3 hour)       Category: Avionics

Today I found the four #6, black, 1" socket-head screws I needed to complete the final fit of the Grand Rapids EIS box on the fuel selector panel. I drilled the holes out and fitted the EIS and its decorative cover. I think it'll look great.

Fitting the box allowed me to take some measurements and see how much room I'll have underneath for the fuel lines. Glad I moved the fuel selector forward from its stock position!

[Superseded.]

  Oct 20, 2008     APRS final assembly and testing (v.2) - (3.1 hours)       Category: Avionics

I completed the assembly of my APRS unit by completing the power wiring, securing all the internal hardware with Loctite, and cutting a viewing window in the top of the case. I glued a sheet of Lexan to the inside of the lid, over the hole. This will allow me to check the three status LEDs inside while I'm programming and testing the unit.

I installed the unit in my truck and drove around town for a couple of hours, and got pretty good results. It think it'll work very well from the air. I tweaked the settings this evening, and I'm looking forward to testing the improvements tomorrow. (Of course, these settings will be modified further when I actually install it in the airplane.)

I figured out that antenna placement has a huge impact on the number of successful "hits" I was making to local i-gates/digipeaters. The large, vaguely S-shaped zig-zag seen in Photo #2 reflected the track that was recorded with the antenna laying on the floor in the back of my truck. The east-west track was recorded later in the day, when I had the antenna taped to the window.

[Superseded.]

  Oct 19, 2008     APRS system (v.2) - (.5 hour)       Category: Avionics

I installed the power jack in the APRS case, began wiring the jack to the internal, regulated power supply. So that I can program the unit at home, I also cut off the stock mini-plug on a 120 VAC to 12 VDC power brick and soldered on a plug that mates with the jack.

  Oct 07, 2008     APRS system (v.2) - (1.2 hours)       Category: Avionics

I decided to move my 8-watt APRS transmitter to my car and install a smaller, lighter, 300 mW one in my plane. I bought a Micro-Trak MT-300 and today I installed it in a plastic case, similar to the previous installation. This one is actually better, because I soldered the 9-pin serial connector directly to the printed circuit board. This greatly decreases the number of soldered connections in the system, which is good for reliability.

Both the APRS itself and the regulated 12V power supply are mounted on standoffs. I'll complete the rest of the wiring soon.

[Superseded.]

  May 31, 2008     APRS assembly - (.4 hour)       Category: Avionics

I finished hooking up the power leads between the APRS circuit board, the power supply, and the power connector. After applying Loc-Tite to the circuit board screws, I screwed the case closed, and now the APRS is pretty much ready to install. I'll probably test it in my car for a while before committing to an installation location in the airplane.

[Superseded.]

  May 30, 2008     APRS assembly - (1.8 hours)       Category: Avionics

After over five hours spent rearranging my workshop, I began final assembly of the APRS system. I decided to install a locking power plug to the case instead of running the power cable through a plastic strain-relief.

After beginning to solder the wires from the D-sub socket to the circuit board, I realized I probably hadn't left enough room to bend the wires around, so I'll just run the wires straight out through the side of the case.

[Superseded]

  May 29, 2008     APRS assembly - (2.0 hours)       Category: Avionics

This afternoon I decided to begin building my APRS (Automatic Position Reporting System). I bought a plastic case, some connectors, RG-59A/U cable, machine screws, spacers, and nuts. I installed the APRS circuit board and 12V regulated power supply on aluminum standoffs, cut holes for the 9-pin D-sub connector, SMA antenna connector and power leads, and began cutting and stripping the various wires that will connect the main circuit board to the D-sub.

Reference Info: This system is a MicroTrak 8000-FA made by Byonics (www.byonics.com). The power supply is a Byonics Micro-Volt 12, which is highly recommended by the manufacturer in this application because this particular transmitter requires short-duration 2-Amp pulses of power, and is fairly voltage-sensitive. The GPS is a Byonics GPS-2, which will be powered by the APRS unit through the D-sub connection. (This connection will also be used for the programming of the unit). The antenna will be a 2-meter "rubber ducky" type, about 15" long, mounted in the wingtip along with the transmitter and GPS reciever puck. The system will be powered from the main electrical bus, and will be switched on and off with a toggle switch in the cockpit. Total system weight: 1.1 lbs. And, of course, you must have a Ham radio license to use a system like this -- which I do.

[Superseded with a different, smaller unit, and a J-pole antenna.]

  Apr 23, 2008     Avionics planning - (1.5 hours)       Category: Avionics

A momentous and productive day! Last night, I researched the dimensions of all the avionics I plan to install, just to verify the suitiblility of their locations in the panel. I'm glad I did this, because I soon realized that if I placed my radios and transponder where I'd originally planned, it would severely limit my ability to mount items on the avionics access door. The Garmin 430W GPS/nav/comm, SL-30 nav/com, and GTX-330 transponder are very deep units. These will have to go on one side of the panel, not separated like I'd planned. The audio panel is a much shallower unit, and will fit on the right side of the panel while still leaving plenty of room for the electrical buses behind.

Photo 1: Two of the buses, pushed far to the right on the access door to make room for the avionics stack.
Photo 2: An improved layout, with the Schottky diode positioned above the buses.

[Entire design later superseded.]

  Sep 28, 2007     Remote compass mount (v.1) - (.6 hour)       Category: Avionics

Today I riveted the stiffeners and nutplates on the magnetometer shelf. It's ready to be installed onto the longerons with ten blind rivets. (I'll do this after everything else in the aft fuselage is complete, and the cockpit and baggage area have been painted.)

  Sep 27, 2007     Remote compass mount (v.1) - (2.4 hours)       Category: Avionics

I was able to borrow a stubby #30 drill bit for my angle-drill, so I drilled the remainder of the mounting holes for the remote compass mount. I had to fabricate some additional doublers for the plate, too. I then scuffed, cleaned, primed and painted the plates and stiffeners. The shelf turned out to be very strong -- I'll bet it would support 50 pounds! Probably overkilll...

I also deburred, cleaned, and primed the holes in the longeron that the plate will attach to. I'm getting used to the tight confines of the aft fuselage. I still don't care for it much.

  Sep 26, 2007     Remote compass mount (v.1) - (2.0 hours)       Category: Avionics

I measured the aft fuselage from inside, then fabricated a custom shelf for the Grand Rapids Technologies magnetometer. The shelf goes between the left and right top longerons, and is strengthened with three stiffeners underneath to make it very strong. This location will keep the magnetometer at least 18" away from all ferrous metal and the strobe pack.

Final installation will have to wait for the arrival of some new #30 bits I ordered for my angle-drill. While trying to back-drill the plate to the longerons, I discovered that my one original #30 drill threaded bit was pretty dull.

  Sep 13, 2007     OAT probe installation - (1.0 hour)       Category: Avionics

I decided that the AN fitting in which I mounted the Grand Rapids OAT probe looked a bit, well, squared-off and un-aerodynamic. I ground the edges off a bit, and it looks better now. It'll look even better after it gets painted to match the airplane someday. (I'll leave the white probe itself unpainted.)

Time to mount the thing. I located and drilled out a 9/16" hole for the probe in the bottom of the right wing, just aft of the middle access panel. I primed the hole and installed the probe, then routed the wires under the wiring conduit, along the bottom edge of the large, nearby lightening hole, and through the ribs (through the small, pre-existing wiring holes). Finally, I secured the wires in several places with zip-ties.

  Sep 11, 2007     OAT probe (primary) - (.9 hour)       Category: Avionics

Like most EFIS systems, Grand Rapids Tech's EFIS Horizon 1 system requires the use of an Outside Air Temperature (OAT) probe. I mounted one for the Dynon under the left wing, and so the right wing seems like a good place for the GRT unit. While the Dynon probe is a slick, polished aluminum cylinder, GRT's probe is merely a small white plastic cylinder with wires coming out of it. It comes with a pathetic little plastic clip, but that's not up to my standards. I decided to drill a hole in an AN816-4D fitting and mount the fitting through a hole in the wing skin. It'll be secured with an AN924-6D nut and a couple of big washers.

After I was done shoving the probe through the resulting hole, I noticed that the white dollop of silicon at the end of the probe had come loose. I replaced it with a dollop of blue Permatex RTV. I also filled the back side of the assembly with RTV, and made a fillet or RTV around the base of the probe, where it comes through the fitting.