Canopy Latches

Little by little, I'm tidying up loose ends.  I measured the mixture and throttle control cable routing about 500 times so I can get cables ordered.  I'm hoping I don't have to have cables custom made, but I haven't found any that match what I need, given my "non-standard" engine and routing.

I think my wire runs up to the panel are finished, so I drilled a hole in the vertical firewall brace on each side of the firewall recess and clamped the wire bundles in place.

I bolted the glare shield fans in place and tested them.  They actually move a decent amount of air, so I think they'll do a good job of both clearing a fogged canopy as well as keeping the avionics cool.  I will wrap the wires and heat shrink the connections once I'm sure the canopy doesn't need to come off again.

I designed and 3D printed fan grills (a new version - my first version a month or two ago was too thin and warped under the screws), just because I can.  I used a high temp PLA filament that's good to about 300 degrees, so hopefully they last. If the heat on the glare shield is too much, I'll either reprint in even a higher temp filament, or I'll send the design off to get cut out of aluminum.

Back to the canopy!  The next step is getting the latching lugs mounted.  These are the fingers that drop down through the canopy deck on the fuselage and get captured by hooks to secure the canopy.  Since there's no way to actually clamp the lugs in place to get them fitted, this seemingly simple task turned into an all day affair.  I wish Van's would make the top portion of the latch a little wider to allow for some side to side cheating after the bolt holes are drilled.  As is, they don't have much wiggle room since the nuts barely fit.  So I bolted them in place aligned as close as I could get to the holes they have to drop through.  Unfortunately, close was not close at all.  The canopy has a tremendous amount of flex when it's lifted and closed (since you lift from one side, so it's not symmetrical force), and the lugs were off by more than 1/8", so they wouldn't cleanly drop through the holes.  I used the dremel and iteratively ground away at the holes until the lugs finally fit.

Even when the lugs would drop cleanly through the holes when I held the canopy from the center (vs the side, as would normally be the case) the issue of the canopy flexing still caused problems.  This is a common issue, and one of the most common fixes is to make some guides for the lugs to hit as the canopy is closed.  I grabbed some scrap UHMW plastic and made some guides that I screwed through the roll bar.  It sounds simple, but this is all off book, so took most of the afternoon to get the guides made and laid out exactly where they need to be.  I put one guide on the outside of each side of each lug.  As long as I don't let the canopy slam down and I guide it down to the last 3 inches or so, the lugs hit the guides and the canopy slides into place.

I'm happy with how the canopy closes now, although I'm still contemplating making a fiberglass and carbon fiber top strip that goes over the canopy at the roll bar.  I've heard that carbon fiber can really stiffen things up so the canopy doesn't flop around like a wet fish when closing and opening.

The other thing I discovered in my testing - the lugs cleared the front of the hole just fine when I would manually push the canopy into place and wiggle it a bit to get the aft clearances good.  However, after 2 or 3 opening/closing cycles where I just let the canopy do its own thing, the lugs would start hitting the front of the holes and make opening the canopy almost impossible from just one side.  I'd heard that a lot of people run into this, but I was really hoping I'd be one of the few who didn't.  Apparently the issue is that during closing, the geometry of the struts pulls the canopy forward.  You wouldn't think that the setup would allow that much movement, but it does, at least without the forward skin on.  My guess is that the forward skin will stiffen the subpanel (where the canopy hinge pins are) up considerably and keep this forward migration of the canopy to a minimum, but I'm not sure.  A lot of people put adjustable bumpers at the subpanel - basically something for the canopy frame to butt up against to keep it from shifting forward.  I'll leave things as-is for the moment, but I may have to go ahead and add these bumpers before I fit the rear window, otherwise the canopy and rear window gap will be hard to judge.

Hurry Up & Wait

The ELT has a little beeper that goes behind the panel to alert when the ELT is going off.  It is connected to the ELT and to the panel activation switch with standard household telephone wire, which is admittedly a little goofy.  Had I known how this was set up, I probably would have bought a different model, but hindsight is 20/20.  This box has a battery that'll have to be changed out every so often.  It's super light, so I just put some adhesive backed velcro on it and stuck it to the back of the subpanel.  That'll make it easier to just reach behind the panel and pull it down when I need to change the battery.

I attempted to install the backup alternator, but no joy.  The oil filter extension that Titan gave me that bumps the filter aft a few inches to clear the engine mount gets in the way of the alternator.

You can see that the alternator won't seat completely against the accessory pad because the bumps for the bolts that hold the alternator case halves together rub against the oil filter extension.  I got in touch with Titan, and they said they do have a 1.4" extension (vs this 2 1/2" one).  I took some measurements, and that will be right on the edge.  It still might be about 1/16" long, but we'll see.  Worse case scenario, I can take the smaller extension to a shop and have them mill about 1/16" off.  Now I just have to wait for the new part to arrive.  I have to hand it to Titan though - they didn't ask any questions and gave me a UPS tracking number within minutes, no charge.

Canopy Back In Place

I obviously still have a lot to do with the FWF, but now that I have the majority of the panel area wiring done, I figured I may as well put the canopy back on so I can start chunking away at the other canopy related tasks.  

Overall, the canopy frame fits a lot better than I remembered.  The fit at the front is still horrible, but there's not much that can be done about that given the issue is with the size of the skins Van's supplies.  The front canopy transition will get completely embedded in fiberglass, so that's when I'll also deal with the fit of the skins by making the fiberglass extend the edges down a little further.

With the canopy shut it definitely makes it feel like a real plane inside!

I made a handle for the left side of the canopy and riveted it in place.  It's small, but it doesn't really take much to get the canopy lifted up.  Next up is the canopy latch setup - the latch itself is already bolted in the fuselage, but the canopy frame needs the catch that the hook of the latch grabs.  I definitely need to create some delrin guides.  The canopy flexes enough when it is lowered that I worry about catching the skins on one side or the other (and really beating up the roll bar).  A common solution is to put some delrin wedges on the front side of the roll bar to guide the latch fingers on the canopy frame.

Cabin Heat Cable

I'm waiting on a few items so I can keep working on the firewall forward.  I was originally going to wait to add a backup alternator until after I was flying and decided whether or not I'd do much IFR flying.  Since the whole point of this plane is to travel, I changed my mind and went ahead and sprung for the second alternator now though.  It'll only take one time of being stranded in the middle of nowhere because of a dead alternator for Rose to decide traveling is no fun!  So I purchased a gear driven backup alternator that goes on the accessory pad on the back of the engine.  It puts out 30 amps, which is more than enough to run virtually everything in the plane should the primary alternator die.

The alternator arrived yesterday, but I still need to get a few other things before I can install it (like Loctite 518 gasket maker - even though the alternator comes with a gasket, you're still supposed to use a thin layer of something like Loctite 518 on it as well).

I've been putting off setting up the cabin heat cable for a year.  It was a chicken or the egg problem - it would have been great to set it up while I had full access to the area, but I didn't want to drill holes and run the control cable before I knew what wires would be where.  Now that my wiring is finished though, I have to deal with the contortions required to work down near the floor.  It was slow going, but a success by the end of the day.

First I needed to get the vertical wire bundles against the firewall routed just right so they could make the transition from underneath the tunnel cover.  The wire bundles are pretty stiff and didn't want to bend tight enough.  I loosened up the wrap a bit, which helped.  I temporarily clecoed the cover in place.  The top of the cover where it meets the sides of the firewall recess is a pretty bad fit and has a 1/8" gap. This area is the cabin heat box, so I'll eventually close up the gap with some foil tape or black RTV to keep the heat where it's supposed to be.

The heat control cable winds its way from the panel through the subpanel and down to the flapper of the heat box.  I drilled a hole in the vertical firewall brace - the cable runs through this hole to enter the enclosed heat area under the tunnel cover.  I didn't like having the cable flopping around, so added an adel clamp on the diagonal firewall brace.  I used the existing fuel line adel clamp screw in the big corner brace to attach a standoff bracket and another clamp there as well.  The clamps are just a hair too big for the cable, so Van's recommends adding safety wire to secure it at the clamps.  Seems to work pretty well.

The cable also got a clamp on one of the bolts that connects the actual heat box to the forward side of the firewall.  I cut the cable to length and ran the core wire through a drilled bolt and attached the bolt to the flapper arm.  That was easier said than done!  With all of my wiring in place, as well as the panel itself, getting two arms down to near the floor was tight!

That was enough contorting for the day.  Just one cable run, but still felt good to finally get it checked off the list.

Heated Seat Rewire & Starter Wire

I can't remember if I wrote about the heated seat wiring before or not.  Basically, when testing my panel wiring and going through all of the circuits to make sure things work, I discovered that the heated seat wiring was problematic.  Anytime I'd flip the switch to turn them on, the fuse would blow immediately (I have the power going through a fuse block with blade fuses).  The wiring is really complicated because of how the relays work to switch the seats from low to high - they switch between running in series to running in parallel to pull different amounts of power through the resistor in the seat pad.  Because of that, I figured I had just swapped some wires in my setup, so I dug the relays out from between the spar carry through space and spent days trying to understand how it should all work.  It doesn't help that the seats didn't come with a wiring schematic.  I finally found someone on VAF who had drawn up a schematic for the same heating pads.  That helped a lot.  In the end, in addition to a swapped wire, my biggest problem was that the DC panel jacks I had mounted on the seat pans were not insulated, so they were causing a short to ground.  I couldn't find any jacks that were both insulated and also beefy enough to handle the amperage of the seats, so my nice and tidy setup had to go.

It's not as slick as just having a receptacle in the floor, but with the wiring changes I needed to make, I just decided to throw on some molex connectors.  All of the changes worked and I now have fully functioning heat.  Making small wiring changes like this sure takes time now that most of the wiring is all zip tied down and in places with limited access.  Hopefully this is the last time!  I had to splice wires in a number of places to swap them around.  I think it's fine given it's just power (vs data), but if I ever have trouble, I'll just pull the spliced wires out and re-run new, uncut lengths.

Back to the FWF wiring!  Things are really starting to get tight.  The starter wires have to route from the left side over to the starter relay on the right.  Given the big elastomer puck on the nose gear, that's easier said than done.  I clamped the starter wires, as well as the CHT sensor wires to the engine mount.

Then the wires swing down towards the firewall.

I made a 90 degree bracket to clamp things to the engine mount right by the nose gear.  From here, the starter cable swings around the elastomer puck and over to the relay.  So another full day and one more wire to show for it! 

PMag Wiring

Continuing on with FWF wiring, the PMags are up next.  All of the wiring for each PMag goes into a green connector that then gets screwed into the body.  There have been quite a few reports of wires coming out of these connectors if they are just inserted and clamped down with the screws.  Out of the many solutions people have tried, I decided to use barrel connectors (at least that's what I call them).  The wire is inserted into a hollow tube and then crimped with a 4 sided crimper.  It gives the screw of the PMag connector more to bite into than just the wire strands.

The routing of the wires to the PMags took a lot of head scratching to figure out how to get around all of the other random things and still be supported.  The left PMag has the wire connector on the bottom and the right PMag has it on the top.  I did the wire contortions and got it all sorted out, only to later stumble on the fact that the PMags can actually be rotated to different orientations.  So I could have changed the left side to be wire side up had I known.  That would have been easier to wire, but that ship has sailed.  While I was messing with the area around the PMags, I also connected the oil pressure sensor (brown/white wire under the oil filter).

The PMags use manifold pressure to assist with ignition timing (although it's not required, so they will still function even without it).  The manifold pressure line goes from the engine, through the firewall to the manifold pressure sensor, then T's off and comes back out the firewall to go to the PMags.  The same line can be used for both PMags by using another T.  It's hard to see where all of these pieces are in pictures - the manifold pressure line is the black tube that runs along the front/top of the engine mount.

Last up for today was finalizing the wire bundle that goes around the battery for some power connections.  I added the two power wires for the PMags.  I didn't have the right size ring connectors for 16 AWG wire (they need to have a much bigger hole for a 1/4" bolt).  I do have some large hole 10-12 AWG ring terminals though, so I just crimped both 16 AWG wires together in the larger terminal and connected it to the stud on the starter relay.

Firewall Forward Wiring

Yesterday was a cold, rainy day, so I decided to spend it sitting in comfort and fiddling with my panel.  I put a seat in and fired things up.  While I had stumbled around a bit with configuration when I first powered everything on the other day, I hadn't really gone step by step yet.  I loaded the ACM and EFIS install manuals on my ipad and spent a couple of hours going line by line through all of the settings.  The system starts by doing a scan through all of the peripherals that are on the Skyview network (all of the Dynon stuff), then you have to manually set all of the devices up to talk to the correct screen.  I was really confused about this, so Friday I had put in a call to AFS and they walked me through what all of the inputs needed to be set up for each screen to handle the combination of devices I had.  This is what makes AFS more of the Android kind of experience vs Garmin, which is for sure the iOS approach.  With Garmin, you get what you get.  With AFS, you have incredible flexibility.  I love having that ability to make it what I want it to be, but it definitely comes with more of a learning curve to get it all set up.

Once I got everything talking to each other, I went through all of the various displays to set up the flight values specific for my plane.  There will still be many hours of configuration and calibrations remaining once I get the plane put together and ready for first flight though.  At least I know that everything is working as it should!

One thing not working - the heated seats.  I flipped the switch to test it out on the pilot seat and it immediately blew a fuse.  I put an ohmmeter on the DC jacks and found that the center pin is grounding out, even though it should go to power.  All four jacks are doing that, so I obviously swapped some wires in my design.  The system uses a couple of relays, and after reading up online about them, it sounds like I'm not alone in having issues with the wiring.  I didn't really have the motivation to contort myself to trace the wires, so that'll wait for another day.

Fast forward to today.  Now that the panel wiring is largely complete (famous last words, I know), it's time to get cracking on the firewall forward wiring.  I have most of the wires laid out in the general vicinity of where they need to go, but the actual routing and attaching is quite the puzzle.  With every wire and hose that gets added, another routing obstacle is created.  Unfortunately, being the first time I've ever done this, I don't know what I don't know yet, so I'm sure I'm going to end up having to redo my routing a few times before it's all said and done.

I started with the power side of the firewall - attaching the amp shunt sensor wires and the starter switch (I had already attached the master switch wire the other day).

I also added a ground strap to the engine case (attached it to a bolt on the accessory cover - where the backup alternator will go).  Next up was routing all of the wires from the left side firewall passthrough over to the various exit points they need along the top engine mount.  For now I just want to get things set up in the general vicinity of where they need to be.  I will attach wires to end points after I have the basic idea sorted out.

I used solder sleeves to attach the pre-existing fuel and oil pressure sensor wires to the wires going to the EMS.  That was my first step at getting things organized.  Next I'll probably need to tackle the Pmag wiring.  It's not complicated wiring, but I think it's going to be a pain just because of the difficulty of access.