Chapter 22 – More Brackets & RCU

Posted on 27 March, 2017 by Airdog

I started off today by razor trimming the bracket for the Throttle handle electrical cable P4 AMP CPC connector.

I did the same thing for the right armrest-mounted Dynon intercom bracket that I just glassed in using 2 plies of BID. On both of these brackets I was able to knife trim them right at their curing sweet spot, so the glass was definitely more on the cured side, but still just a tad pliable . . . so it cut well.

I then laid up 2 plies of BID on the bottom side of the Throttle handle electrical cable connector bracket. I used a small flox fillet in the corner and peel plied the glass junction with the sidewall.

I did pretty much exactly the same thing on the Dynon intercom bracket only for a bit more strength I used 3 plies of glass on the bottom side.

Speaking of brackets, I just received this today so I thought I’d throw it on the blog. This is the fuel injection spider mounting tab that goes on the top centerline of the engine. Yet just another item that will go on the shelf for the time being.

With my bracket glass curing, I started in on mounting the 4 beefy relays into the gear Relay Control Unit (RCU) box . . . fitting name, eh?! The first relay to go in was the clear cased 3 pole Auto Extension (AE) relay, RL000. It handles the actual engagement of the gear Auto Extension feature and also is a pass-thru for all the major electrons running the gear up or down.

I ordered this relay specifically with bottom mounting tabs, with the corner of the left tab needed trimmed diagonally just a hair for it to fit properly. It mounts with a 4-40 screw on each side, each coming in externally from the back. All the mounting screws coming in from the back side are countersunk to allow the back surface of the box to remain flat, which facilitates ease of mounting the box to the aft side of the Napster bulkhead.

Next relay up to get mounted inside the box was RL003, or the AX relay. This relay is the one I added back into the mix that charges the small 1.2A backup battery that was provided in Jack Wilhelmson’s original design. Relay #3 takes control of the system in case of a power emergency to drop the gear down using the 1.2A backup battery for power. In Marc Zeitlin’s new gear wiring design he doesn’t use this relay since his system incorporates a manual (ratchet) drive for emergency gear extension.

Finally, as for relay #3, I mounted this guy first since it has a unique feature that needed to be dealt with that the other two black relays don’t: down along the top side of the relay is the RXEF-250 wafer style fuse soldered into place that’s used during backup battery charging. Getting under this fuse to install the K1000-6 nutplate would have been a lot more difficult if I couldn’t get in from the side (where the other two relays sit) to mount the nutplate. After I mounted this relay, I put some double sided foam sticky tape underneath the wafer style fuse to keep it mounted to the front of the relay for anti-vibration. I also tipped the box right side up and glopped some E6000 adhesive (yep, the stinky stuff) onto each edge of the fuse to keep it secure to the relay, banned the box outside on the deck for a few hours while it cured and I took off to run some errands.

Upon returning from my errands (which included buying parts for the flexible sander Nick Ugolini describes how to build on his blog) I installed the last two relays: RL001 & RL002 [Note: Simply for space I truncated the relay IDs and labeled them on the actual relays with RL0, RL1 … etc.). As you can see, these two relays simply control gear up and gear down, respectively. All went well except for the life of me I couldn’t find a 6th K1000-6 nutplate to use on the top side flange of RL002. After searching for a good while, and simply not finding the pack of 23 I show having on hand (simply maddening!), in order to get this thing wired up tonight I improvised, adapted and overcame by using an aluminum binder stud, cutting off the top and then quickly Dremeling a not-so-pretty slot for a bladed screwdriver. I doused it with a good measure of blue Loctite and in it went… Voila!

Here’s another shot of my mounting improvisation . . .

Over the next couple of hours I confirmed & verified the wiring in this box matched exactly what was on the diagram. Having had to pull all the terminals off their posts, I used a pair of channel lock pliers to compress the terminals just a bit to ensure their clamping pressure was nice and tight. I then slowly replaced all the terminated wiring back onto the relay posts, performing a continuity check as each set of wires went back in. After all the wires were back in place, I zip-tied them into place to ensure no wires would be vibrating and wreaking some future electrical havoc by gnawing through a neighboring wire, etc.

Here’s just a closer shot of the internal RCU box wiring . . .

I then cut & terminated all the wires with AMP CPC sockets. Again, as I finished each wire I performed a continuity check to ensure all was electrical good on that wire circuit from source to connector.

With all the RCU box wiring set to be terminated into the AMP CPC connector, I called it a night. I may have actually done a bit more but it was quite late and I was collaborating online with Marco (who was in Hawaii for work!) on the specs for the AEM box.

Chapter 22 – RCU Box & Brackets

Posted on 26 March, 2017 by Airdog

I didn’t get the intermediate steps documented since I’ve been out & about this weekend with friends. Here is the final result of the Clickbond mounting for the Nose Gear RCU box. Again, I used 3 plies of BID along the top row (2 Clickbonds) . . .

. . . and 3 plies of BID along the bottom row (3 Clickbonds). After curing, I pulled the peel ply and cleaned up the goobers. Thus, the RCU box is officially mounted.

A little sideline tasker I completed was to drill and flox in place this Adel clamp for the Throttle electronics cable that terminates into the P4 Connector.

After pre-drilling the 4 screw holes and the 8 holes for the K1000-6 nutplates, I then did a final trim & sanding on the Dynon Intercom bracket. I determined where its position needed to be and marked the sidewall. I then 5-min glued the intercom bracket to the sidewall.

I then laid up 2 plies of BID (pre-pregged of course!) on the top side of the intercom bracket, and peel plied it.

I pretty much followed the same steps for the Throttle handle electronics cable P4 connector bracket just forward of the instrument panel on the left side. After 5-min glueing it to the wall, I laid up 2-plies of BID and peel plied it.

These tasks above are all on a list of 10 electrically-related items that I want to have finished before I move on to the wheel pants. Once these brackets and the RCU box wiring are completed, I’ll be down to about a half-dozen items on the list.

Chapter 22 – Gear RCU Wiring

Posted on 21 March, 2017 by Airdog

Today I finished wiring all that I could on the Nose Gear Relay Control Unit (RCU). My first task of course was to trim the lengths of the cross connect wires to the outboard relays (#1 & #3). I then re-terminated the wires with new red FASTON terminals and double checked that all was good with those.

I then started cross-connecting wires from the 3 lower relays (black) to the top AEX relay (clear). One of the big challenges, which I think is a bit analogous to solving a puzzle, is to take the logical wiring diagram on paper and determine how the wires and components actually hook together in real life.

What looks like a long wire on the page can of course be no wire and simply a lead to a diode or resistor. Such is the case with the RXEF250 Minifuse that looks like a brown wafer overhanging along the top side of relay #3. Although on the diagram this shows up in the middle of wire run, in fact this Minifuse IS the wire run. The diodes at the bottom of the relay connections in the pic below is also pretty much the same way. On the diagram it looks like 3 diodes suspended mid-point in wire runs, when again they are the wire runs, all starting out at the AEX relay coil’s negative post. Out of 3 diodes hooked to the coil post, only one them is physical attached to a wire, while the flyback diode is terminated with the positive power wire, and one is simply a loner heading off by itself to a Common terminal.

The wires going every which a way again will get corralled, secured and terminated into the 19-pin AMP CPC connector.

Speaking of connector, here is the AMP CPC connector for the gear RCU.

And a shot of the aft side of each connector half.

Besides physically mounting the relays, double checking the wire terminations & cross connects are correct and the terminals are attached tightly, the only thing left to do is to cut the wires to length and terminate the ends to fit into the connector. Thus, on to wiring the AEM!

Chapter 22 – Initial gear RCU wiring

Posted on 20 March, 2017 by Airdog

With the Nose Gear AEM box designed in CAD and sent to Marco for final collaboration and then 3D printing, I got organized to start wiring the internal components of both the RCU and the AEM. Since the weather is getting better only sporadically, with the seemingly incessant high winds as the norm, I figured I would trudge on to finish up as much of my electronics as possible until good weather allows me to fly & glass.

The first order of business was implementing the $1.49 clamp I picked up at Michael’s to allow me to employ the fixed iron method that is detailed in a Youtube video that Marco sent me, and also as I had seen prior in an EAA soldering video (featuring one my local Chapter 186 members, Dick Koehler). After using this method a bit without the clamp, I really liked it so I bought the clamp and made up my poor man’s version of it:

And here’s the YouTube video on the fixed iron method:

Ok, let’s talk about box configuration. For mainly external reasons, I needed my RCU box to be no more than 2.1″ tall internally. This meant the space for wiring connectors would be tight, and might have meant a fair amount of soldering, which as you can see above, I was fully prepared to do! ha!

Well, late last summer I had disassembled a friend’s dishwasher to get rid of it and recycle the parts. I threw the wiring harness in the garage to use for test wire (vs Tefzel) any time I needed “trash” wire. Well, I had it upstairs since I was cutting off pieces of this wiring harness to test circuits, and low and behold I found some 90° right angled 0.25″ FASTON connectors on the harness. I cut them off and inspected them closely and was able to pull away the wires’ outer insulation from the plastic retainer to reveal bright shiny copper underneath. Since the clamp part of the connector was spotless, I decided these would work great for the 22AWG ground side of the relay coils and pressed them into use. Since I didn’t have enough, I bought a few more for the relay coils’ positive terminal sides.

Here I’ve laid out the components further so the wiring flows in accordance with the wiring diagram. I crimped the normal FASTON terminals in place on the relay interconnect wires, first bending the terminals very slowly & carefully at a forward angle to give me just a bit more clearance under the lid. Also, you can see on the blue flag connector on the right relay that besides the 18AWG power wire, I crimped the flyback diode and 56.2 Ohm resistor into the terminal as well.

[NOTE: my relay interconnect wires came out too long –meaning too tall to fit under the RCU box lid– so I need to cut the wires shorter & re-terminate the terminals on the outside relays].

I then focused on relay #3, which is the heart of incorporating the small 1.2A backup battery into this system, as Jack has in his original nose gear system (Note: Marc Z’s version doesn’t have this relay since he uses the mechanical gear down backup system). I soldered the flyback diode in place between the relay coil tabs, then soldered the 22AWG black ground wire in place, with all this soldering taking place at the red terminal. I then soldered a Schottky diode (middle left) to the resistor going to the positive side (blue terminal) of the relay coil. This Schottky diode & resistor make up the backbone of the charging circuit for the 1.2A backup battery.

I then covered my solder joints with heat shrink tubing.

With that, I called it a night knowing that tomorrow I’ll have to cut my relay interconnects shorter and re-terminate…. (big sigh)

Chapter 22 – COM1/COM2 Radio Swap

Posted on 12 March, 2017 by Airdog

After pulling the trigger on my Garmin GNS480 I was doing some research on wiring it up when I found a post on the Dynon forum from a Dynon tech saying that the Dynon 2-place intercom should no longer be used to control two radios. The huge selling point for me in buying the Dynon intercom was SPECIFICALLY that it was designed to handle TWO radios!

In a phone call with a very knowledgeable RV builder, Don, who I met on the Aeroelectric Connection forum and who happened to also be selling a Garmin GNS480, I pointed out my recent discovery regarding the Dynon statement on their intercom. Don stated that he knew a number of RV drivers that were using this exact intercom to control two radios and they seemed really happy with their installations. He further stated that since he was good friends with Rob Hickman, founder of Advanced Flight Systems, that I should give Rob a call to confirm this not-so-good information. So, I did just that.

Rob and I talked for a good bit, and he did in fact confirm this disturbing news regarding the Dynon intercom (AFS sells the same exact intercom, and yes, these companies are now one….). According to Rob, he knew of no work-around and that unless I wanted to keep my COM2 radio turned off or the volume all the way down, I would almost certainly get bleed over and crosstalk between the two radios. In essence, he said the intercom simply came down to being a hopeful design in theory, but not a good one in practical application [as an aside, none of the advertising that I saw on this intercom changed to state that is was no longer a viable solution for controlling two comm radios].

I looked around for other alternatives but I was really relying on the size and touted functionality of this intercom as the linchpin of my two comm radio design in my Long-EZ. Every audio panel I found simply took up too much panel real estate that I just didn’t have, and the features were either way too much or way too little for what I had already dialed in with the Dynon intercom. I figured in my mind there needed to be a way to make this little intercom do what it had been advertised to do.

Well, I posted my question on the Aeroelectric Connection forum (if you’re not on it, I highly recommend it) and got a response the next day with a link to the VAN’s forum. There, an RV builder who moonlights as an electrical engineer (or is that vice versa?!), Deene Ogden, who had the exact answer to my issue. In the Dynon intercom manual it merely has you hook up the intercom to common on a switch (or relay) with one side going to the COM1 radio and the other going to the COM2 radio. Well, that results in the crosstalk issue I highlighted above. The answer is simply go bigger, as in a bigger switch or relay. Instead of a single pole relay (the white one below) I needed a 3 pole relay to also switch the Audio OUT of each comm radio into the appropriate pin on the Dynon intercom.

Thus, with the relay off (my control stick switch in the center off/COM1 position) the relay is as follows (1-3 represent the C-NO-NC set for each pole):

PTT: COM1 (NC)
COM1 Audio In: On/NC
COM2 Audio In: Off/NC (pin not connected)

When the relay is powered on (my control stick switch moved up to the ON/COM2 position) the relay is as follows:

PTT: COM2 (NO)
COM1 Audio In: Off/NO (pin not connected)
COM2 Audio In: On/NO

This is reported by Deene and others to do the trick, so as you can see above I bought & rewired/re-soldered the connections to a 3PDT relay.

I also have been doing a bit of verification on my headset jack connections, so below I used the wiring harness that I received with the intercom that I bought from Dick Rutan to test the headset jack housing configuration (yes, I’m name dropping because it’s pretty cool that I’m using something Dick Rutan constructed to check out my configuration!)

I of course need to finish up my COM1/COM2 swap relay with some heat shrink tubing & wire labels, but beyond that I’m done (again!) with my com radio swap relay wiring.

Chapter 21 – Newton Fuel Caps

Posted on 11 March, 2017 by Airdog

I got a note from fellow Long-EZ builder Brian Ashton from Alaska asking a question about my fuel caps that I mentioned in a post on acquiring fuel cap keys from ACS for these caps. Well, to answer Brian’s question I had to go back and do a bit of research on my own fuel caps. Turns out, I was remiss in ever actually posting anything about my fuel caps, so I am doing that now to correct my oversight!

Way back in May 2012 –after a back & forth discussion with a builder that decided he wasn’t going to use these caps anymore– I bought these Newton fuel caps on Ebay.

These are the locking style caps as you can see in the pic below.

I was looking for the Newton A36LFF style caps with the solid flange vs. the flange that has bolt holes around the perimeter for attachment. I believe these are slightly different than the A36LFF in that the flanges on these are simply sans holes, while if I’m correct the actual A36LFF has a raised lip around the cap and a slightly lower flange to allow it to be glassed in place.

Below is a shot of the interior side of the fuel cap.

And a shot of the retaining flange, underside.

I definitely remember for the price that I would make this configuration work since the pair of these caps were way less than buying just one A36LFF cap from ACS! Plus, the flange showing on the external fuel tank surface versus just the cap peeking out is much more visually appealing to me. I understand the issues of securing it, and I have an idea or two that will keep these guys in place.

One cap does have a couple of very light scratches (which I believe will happen over time anyway) and I’ll make a point that while these have a goldish appearance in all these pics (from the original seller) they in fact have the normal fuel cap silver aluminum finish.

Ok, with the mystery of the missing fuel caps taken care of, I’ll press on!

Chapter 22 – Fake it ’til you make it!

Posted on 10 March, 2017 by Airdog

With the weather still not up to par for flying on the days I’ve been available, I’ve been working to get more stuff in the coffers for the eventual final push on this build. I received an order from Mouser with everything but the Laser Altimeter that I’ll need to implement Marc Zeitlin’s new nose gear system AEX mod, combined with Jack Wilhelmson’s original emergency backup battery feature. After sorting through a myriad of revisions on the melded, morphed version that falls between Marc’s new system with Jack’s old system, I think the new AEX with battery backup and emergency extend is about the best version it can be.

There are some tradeoffs of course with this new system, and some of that will be in weight. Although I guesstimate it’s not huge, I’m thinking this new system will be a bit heavier with the required laser altimeter and beefy relays in the mix. To offset some of the added weight effect, I’m mounting these new monster relays in an enclosed box on the left, aft side of the Napster bulkhead. That should help a tad with moving the CG ever so slightly forward.

Speaking of weight, I also received two new brass fittings for the oil pump from Buly. We actually talked a couple of weeks ago and he said he was going to ship them out, but understandably got sidetracked with the sale of his Cozy. Sad to see him sell it… yet another one of the Ol’ Guard out of the game.

Obviously these fittings are somewhat unique, thus the reason Buly sent them to me rather than just have me order some off of ACS. Nick Ugolini did recommend that I acquire fittings for 5/8″ tubing, but Buly had these 1/2″ fittings at the ready, and I figured 1/2″ will do just fine. Maybe these will save a bit on weight with a little less oil coursing through the heating system lines. Below you can see that I test fitted these new fittings on the oil pump. Since these brutes are brass, they of course are significantly heavier than if they were aluminum. But hey, they fit, are in hand and will allow me to have heat in my airplane!

Since I also got a rather sizable ACS order in as well, I decided it was time to take a break from my logistical duties and knock out something that I had started quite a number of months ago. I had already spent quite a few hours at the beginning of the week logging a bunch of purchases in my tracking spreadsheet . . . and I’m talking stuff from last August, so I wanted to get a bit organized. My goal before the weather gets warmer, when I can start back on doing some low cost (read: sans high heater settings) layups is to get my recent flurry of research, documentation and instruction manuals put away in my build HQ area (my living room!). I also spent a good half-hour today doing a cursory cleanup of the shop, but another hour is in order before it will be ready for production again.

Ok, so my latest mini project was to assemble a bunch of pieces of wood that I cut late last summer to create a cockpit mockup & simulator to allow me test the ergonomics, placement, switchology and operation of my avionics and instruments. This harks back to my original fuselage mock-up to check for how the plane would feel in its stock dimensions (remember, I widened the cockpit 1.4″). Now, this version will enable me to mount all my current avionics, plan for new ones, and give me a really close estimate on final wiring requirements for all my panel components. This latter reason is why I made this cockpit simulator to allow for the installation of the Triparagon.

When the Triparagon is installed I’ll wire up the panel and fire up the components not only to do a good ops check on them, but also to configure them in the panel. Also, this cockpit mockup will also allow me to finalize any wiring required on the Triparagon.

You may note looking at the pics above that the wood looks a little ratty and non-uniform, and you’d be right! So far, this entire mockup has been made of completely scrap wood.

Below you can see the right side armrest. Since I won’t be mounting my second Infinity control stick into the actual airplane, it will get mounted here (although I probably won’t wire it up) into the right side armrest.

On the left side I’ll use the cockpit mockup to figure out exactly where the throttle will get mounted, and how everything else will be configured on the armrest. You may note the different gray colors of the two armrests, which is me using these as paint color swatches to help me decide the color (or colors!) of my interior cockpit paint.

I’m accomplishing this cockpit simulator mockup construction in 6 phases, and right now I just finished Phase IV. Phase V will be cutting and installing the avionics in the instrument panel, and Phase VI will be configuring the two separate armrests with the control stick and throttle.

As you can see, once I get this guy up and running, I’ll be able to test out different component and switch locations no matter what’s going on with the actual cockpit. In addition, this mockup will really come in handy while I’m sanding away on my Long-EZ in prepping it for paint, all the while ensuring that my eletro-whizzies remain dust free!

As you can see, I’m slowly moving towards getting back onto the build. I do need to really try to knock out this Instrument rating though, although the pace of instruction is very much glacial at the moment!

Chapter 22 – Success!

Posted on 3 March, 2017 by Airdog

I got word this morning that my IFR training is back on (there was an issue with my FBO and Part 141 training… all clear now).

In the mean time, I had two separate phone calls today with Rich at Aircraft Extras, Inc. to finally get these AG6 warning annunciators programmed! After following some instructions in an email that didn’t work (my fault, I entered a data field incorrectly) I called Rich. He talked me through some steps and helped me understand a couple of the data fields well enough that I got off the phone to tackle it all again. Well, the umpteenth time is a charm because it worked!!! Finally! So I spent the next 6 hours programming and documenting every parameter for each warning screen. I then did an operational check on each alarm screen by inputting the amount of voltage that it needed to see to kick off the alarm. Thus, now each alarm screen works exactly as it should… (yeah!)

It was a bit tough there for a while on getting these AG6s programmed, but I’m really glad I stuck to the plan for using them. I can now say that all my major warning annunciations (non-EFIS) are good to go! One other thing I’ll point out on my AG6 configuration is that on almost all of them I’ve turned off the “Green OK” screen so that I get just the warning screen & only when it alarms. Clearly, on the canopy, landing brake and nose gear I wanted positive feedback of what was going on with these components. I’ll also point out that only those issues that would result in an immediate safety of flight issue, damage to the aircraft/engine, or fire are denoted with a red color. The amber alarms screens show up clearly visible and are an attention getter as well, but I wanted the really bad stuff (obviously, my opinion here) depicted with red. Finally, I’ll note that the green screens only come alive when the action they represent has been 100% completed. For the canopy, note that it doesn’t say “Canopy Closed,” but rather “CANOPY LOCKED.” Same for the landing brake being stowed away and the nose gear extended all the way down. I actually had a screen stating “gear locked” (since it solved my double gear up/down alarm entry … see below), but after a bit of thinking I decided that I wanted to denote “GEAR DOWN” since to me that communicates more succinctly where the gear is compared to “GEAR LOCKED”.

Moreover, Marc Zeitlin just released his new version of the nose gear automatic extension system (AEX) which streamlined the signal output from the nose gear system with a single wire to each nose gear status indicator light. What I had to take into account however was that with these one wire outputs it meant one input for the respective gear up and gear down signals. This meant I had to parse out the normally paired GEAR UP and GEAR DOWN warning screens and put them on separate inputs. Well, the way the AG6 works is that each alarm has a specific screen code, and the screen code can only be used once in the system since it points all the data to that code. Well, luckily I communicated what I wanted and Rich talked me through how to “trick the system” by using all the descriptive parameters of the GEAR UP/GEAR DOWN reference number under another unique alarm code (I overwrote the vacuum pump alarm code since I definitely will not be installing one of those in my plane). With two separate GEAR UP/GEAR DOWN alarms on Annunciator #1, all I had to do (yeah, right!) was turn off the alarm screen (red or green) that I didn’t want to see for each separate GEAR UP/DOWN alarm.

[As a point of note, there were 2 EZ workarounds for the above issue even if Rich hadn’t helped me out. As I mentioned before, I could have used “GEAR LOCKED” which is a different screen number. Also, I could have programmed one gear condition on AG6 #1 and the other on AG6 #2, although I did want my final gear positions annunciations in the same place… ALTHOUGH, to further convolute this: my “GEAR UP TRANSIT” and “GEAR DN TRANSIT” indicator lights (not AG6) will not be colocated on the panel so that peripheral vision and color tell me gear moving up or gear moving down … nuff said!]

Ok, speaking of Marc Zeitlin’s new AEX, I’m starting to actually receive my component orders to implement that system. I have yet to order the actual Laser Altimeter, but pretty much everything else is on its way. Below is the 12V-to-5V converter that I just got that is needed to drive the 5V laser altimeter. I wasn’t sure which one to get so I just bought the same exact one that Marc has since his system is working. Hey, if it works, don’t mess with success . . . right?!

The other components I got in (as if I didn’t have enough of these things!) were 2 different airspeed switches. The one to the left is a Normally Closed airspeed switch and used to sense when the aircraft is less than 90 KIAS. The one to the right is a Normally Open airspeed switch that senses when the aircraft is traveling 40 knots or faster. These will be installed in series so both parameters must hold true for the AEX to function (along with the throttle being retarded to <10% power and the laser altimeter reading less than approximately 350 ft AGL).

Marco had a question on my last blog post regarding Marc Z’s system that I wanted to clear up here. Here’s Marco’s question:

“What happens if all those [AEX] conditions are met and the gear auto-deploys, then you find yourself a little low on the glide path, and add more than 10% power to correct just before you land? Will the landing gear go back up? Or does it stay down after deployment?”

This is an excellent point, and I should have clarified this in my last post. The answer is NO, the gear will not go back up because the AEX circuit latches. Only by cycling the gear switch all the way down and back up will it then raise the nose gear on the command of the pilot to very specifically override the AEX system. Otherwise, the AEX will keep the gear deployed until the pilot either lands the plane or cycles the gear switch toggle to intentional raise the gear. I’m glad Marco asked this question so I could clarify this point!

Depending on weather my Instrument training schedule is up in the air. As for the build, as time allows I have about 4-5 electrical system tasks I want to finish up. Then I plan on seriously getting back to some glassing, including (don’t laugh!) . . . the wheel pants!

Chapter 22 – “Early upgrades” . . .

Posted on 28 February, 2017 by Airdog

One good thing about not getting this plane built on schedule is that it allows for me to implement really good upgrade mods that would normally mean downtime & increased complexity on a flying bird. In other words, I can take just a scant bit of extra time and roll these new mods into the build plan in whatever area before I ever start in that specific endeavor. Two such mods that I’ll discuss below are the electric nose gear system and the heating system.

First off, I finally did a bit of research and decided on the style of latch I wanted for my oil dipstick access door on my cowling. I like the way the one below operates so I picked one up from a guy off of Ebay. For those curious it’s a Hartwell H2868-1. I like this specific version since most of the ones that are this style simply have a large square plate with a hole in each corner for mounting. With the wings of this “H” style it will allow me to bend those just a hair to match any curvature I may have on the oil dipstick access door, which in turn, matches the curvature of the upper engine cowling. In addition, the main reason I wanted a latch-for-the-hatch is to preclude the complexity and pain of having to use a screwdriver to undo any number of CamLocs just to check the oil! Plus, as with everything we do, I simply think it looks cool… ha!

I don’t normally include this type of stuff on my blog, but since the use of my laptop DIRECTLY impacts my airplane building I thought I’d make an exception this time. So my MacBook cord finally gave up the ghost. No worries, I’ll just pop down to the store sez me to myself and pick up another one . . . how expensive can they be? Well!!! $78 is how expensive they can be. Sorry, not gonna happen. Thus, I fired up the soldering iron and soldered what few molecules of the outer shielding I could find, built a bit of a solder bridge (that’s always fun!) and slapped some heat shrink on it. And Voila! Works like a champ!

Now, back to real business.

My build buddies apparently understand that I like bright shiny objects and will take off after them with aplomb if any catch my fancy. Well, Dave Berenholtz from OZ obviously understands this too well and sent an email asking me if I was aware of what Marc Zeitlin was cooking up in his evil lair. Apparently Marc was dissatisfied with the standard operations of the Automatic Extension (AEX) feature of Jack Wilhelmson’s EZNoseLift electric nose gear system. The AEX simply provides an automatic feature of retracting the nose gear after takeoff once the airspeed is above 90 knots, and conversely, will extend the nose gear if the airspeed is less than 90 knots. Short and sweet.

Well, Marc undertook about a year-long project to refine the AEX system, not just for Jack’s system, but any aircraft actuator-centric system (I’ll note for clarity that in Marc’s quest, apparently the “X” got lopped off the end of “AEX” and now it’s just the AE system). IMO, Marc’s system is fantastic in that by adding another airspeed switch, a throttle “microswitch,” and a laser altimeter, it provides a comprehensive set of parameters that must all be true for the Auto Extend to activate and deploy the nose landing gear:

1: Throttle less than 10% open
2. Speed greater than 40 knots (user programmable)
3. Speed less than 90 knots (user programmable)
4. Altitude at or below 350 ft. AGL

Ok! Wow, this is truly fantastic news for us Canardians! I printed out Marc’s description of the system and the electrical diagram and got to work since I wanted to assess how this would integrate into my system.

Initially, this all seemed too good to be true! Where was the catch? Well, as always seems to be the case there were two specific problems with this new system: the first in relation to my build and the other, a general operational requirement that I desired, which was offered in Jack’s original system but removed in Marc’s modification.

First, the operational requirement: Marc’s version offers no backup battery capability since Marc personally uses the ratchet drive backup system to extend the gear in case of an electrical failure. Jack sells his EZNoseLift systems with the option of the mechanical ratchet drive backup -OR- a small 1.2A backup battery that will lower the gear sans ship’s power if the electrical system fails. Hmmm…. Since I have the backup battery, this was not a good thing in regards to my system.

Next, as for the integration into my build? Marc’s version requires a 3PDT switch to control the gear up & down. My already terminated and installed throttle-mounted SPDT nose gear switch is in the “done” column and is perfect for driving Jack’s EZNoseLift system. Moreover, since this is an F-15 throttle handle, how this rare switch is mounted and its metal hat switch form factor make it very difficult to just pull, plug and replace with another switch. Moreover, I really have to say that I love my throttle handle just the way I’ve now configured it! On the pic of my throttle handle below you can see (mid-side handle) the stepped-hat nose gear up/down switch.

Also, one thing was clear as I stared down this road of integrating the new parts of Marc’s upgraded system while keeping the best part of Jack’s current system, and that was I really needed to truly understand and have comprehensive knowledge of how both these systems worked. To be honest, with so many versions of Jack’s system out there, I wasn’t even sure what my switch panel looked like! I went down to the shop and snapped a pic of the switch panel face . . .

. . . and the actual wiring of the switches on the backside of the panel in order to identify the correct switches and wiring circuits.

After pondering my gear switch issue for about a day, out of the blue I had a Eureka moment: Duh! just swap out Marc’s required 3PDT switch with a 3PDT relay… right? Problem solved. Uh, but wait a minute sports fans. With this being a CANARD gear switch, a problem is presented in simply swapping a switch out with a relay since there’s that pesky “-OFF-” position on our gear switch that doesn’t translate over to a “middle position” between N.O. and N.C. on a relay. Obviously, on canards we don’t simply use a binary, all-the-way up or down gear position (except for TOs/landings), but use the gear switch to position the nose in a myriad of heights off the ground when parked. Thus, my requirement was to be able to hit the nose gear up/down position, have it run up/down for a few seconds and then move the switch to the “OFF” position to stop the gear from moving any forward. Again, with most aircraft you simply have an up or down gear position, but we Canardians apparently like to be eccentric!

I was at the juncture of simply knowing that I wanted to replace Marc’s required 3PDT switch with a relay that I could then subsequently control with my throttle mounted SPDT switch. But how? Not smart enough in the ways of electrons, I posted my dilemma onto the AeroElectric Connection forum. Within an hour Charlie England started off his response with a question that gave me my answer: “How about 2 separate 3 pole relays?” Yes, one relay would control up and the other down. When my throttle-mounted switch was in the middle OFF position, neither relay would be powered on to do any action so the system would be “at rest” . . . or OFF. I had found my middle position!

[Just as a point of note, since Marc’s 3PDT switch positions were wired to create 2-N.C. states and 1-N.O. state in the up position, and opposite in the down position, it allowed me in the end to only need one DPDT relay and one SPDT relay to replace the 3PDT switch.]

With the switch issue taken care of, now it was time to tackle probably the biggest electrical challenge I’ve ever faced. I had asked Marc & Jack, et al, on the Cozy forum if there was a way to wire back in the 1.2A backup battery into Marc’s design to provide a means of getting the gear down if a total electrical failure were to happen. I had some back and forth on a type-of-relay question I had, but nothing on the backup battery except an expressed desire by some to see that “put back into the system.” With no real response, and having one solved problem (the new AEX system) creating a new problem (no backup emergency gear extend feature), I figured it was time for the proverbial: “Well, if’n you want somethin’ done yer gonna hafta do it yurself!” (Said in Ken Curtis’ Festus voice from “Gunsmoke”).

I spent a day and a half deconstructing both Marc and Jack’s respective systems, and then ala “Tony Stark” (without the flare, billions of dollars, Hollywood CGI or Jarvis) I melded the backup battery feature from Jack’s system into Marc’s new design. Thus, after chasing imaginary electrons around on paper over a couple of days I was finally able to meld the backup battery and emergency gear extension feature back into this promising new & improved system!

After verifying that my new combined design worked, I then cleaned off all my specific extraneous system info to then submit a generic copy onto the Cozy forum. I received word back from Marc Zeitlin that it would work as per my (actually his & Jack’s) design, with a number of “why-didn’t-you-use-this-component-vs-that-one” type questions, which is great since that’s how system designs are optimized. So now I have some system design “homework” from Marc that I will attempt to iron out.

Regardless, doing nothing else from this point on (besides buy all the required components!) results in a new baseline electric nose gear system that provides a very usable AEX system and allows me to incorporate the backup battery feature/emergency gear extend feature.

If you’re curious, here’s a final thought on reasons I chose the battery backup system vs. the mechanical ratchet wrench backup gear deployment system: the battery weighs considerably less, takes up no panel space as does the mechanical unit, and most importantly –for me– if I’m working any non-standard issue while in the process of landing, I don’t want to be messing around with a ratchet (which itself weighs as much as the small backup battery) and spending time getting the gear down when the flick of a switch will do it for me. Finally, a very important thing to consider that I learned while flying in Marco’s Long-EZ is that IF YOU DROP SOMETHING on the floor, it is no longer something of use to you! And unless you tie off that ratchet handle, it may end up being nothing more than added weight in your airplane while you WISH you had a means to get your nose gear down [just saying . . . IMO!]

Now, on to my final topic of this LONG post.

I had a good discussion with both Buly Aliev and Nick Ugolini regarding the integration of Buly’s oil heater system pump and system design. I have lots to think about still on this system, but one thing I did take away from my discussion with Nick is the heat output is best realized by controlling the speed that the oil pump is pumping in hot oil into the system. Thus, in able to control the speed of the oil pump, one method utilizes a PWM controller switch, so that’s just what I picked up. I can now say, “Behold, the oil pump and its PWM controller switch!” (not that I will necessarily, but I can if I want . . . !)

That’s all for now folks!

Chapter 22 – Taking a break…

Posted on 14 February, 2017 by Airdog

Today I started out studying for my Instrument Pilot’s rating for a number of hours before I hit a serious wall. My brain was mush so I rationalized spending a few hours on getting my AG6 programming data organized. I consolidated all the programming parameters onto one sheet per AG6 (they’re labeled AG6A & AG6B), printed them off and stuck them in my Electrical Wire Book right behind Wiring Diagram #18: AG6 Warning Annunciators.

Since I still had the electrical leads connected to AG6 #2 (AG6B), I decided to go ahead and program it as well. It took me a good hour to get all the parameters dialed in –there are 32 parameters just for the individual warning screen definitions alone– and another 45 minutes trying to troubleshoot an issue with the very last alarm screen: the STRTR ON warning screen (which denotes a hung-up starter) which for some inexplicable reason [at least to me] is only showing the green STRTR OK screen. Not gonna cut the mustard!

After no joy in troubleshooting the Starter On warning screen, I emailed Rich at Aircraft Extras, Inc. to get his input on how to fix the issue.

I also whipped together a very quick video to offer a little insight into what I’m up to on these AG6 warning annunciators. Be forewarned! The AG6 screen colors & labels don’t show up very well. But you’ll get the general idea nonetheless.

Ok, back to studying!

A Long EZ Push

The Building of Long-EZ N916WP

Category Archives: Major Systems