So it’s SuperBowl Sunday and I don’t have a team in the battle this year or since 1985, thanks Bears! I had my usual breakfast with Glenn and headed to the shop to tidy up some wiring stuff. Really all I had planned to do was finish the four wires that came off the intercom wiring harness that I made yesterday. Three were for the Skyview system to give unmuted audio alerts through your headset for things like warnings. The fourth was for a dimming feature for the intercom panel so when the Skyview dims so do it. Once that was done I just set out to really clean my work space from all the wiring. During this process I decided to move the fuselage for the eventual addition of the wings. I needed to place it so that I had room to work all the way around but also didn’t get in Glenn’s way for his shop work. With those requirements I came up with the location and we swung the fuselage around.
As we are sitting and talking about the planes and future pancake fly-in’s Glenn says let’s put them on! I say heck yeah and grabbed the tools needed. Glenn had some temporary bolts that he ground the threads off so they wouldn’t damage the wing spars. My girl, Tricia, wanted to be here for the wing mating so I called her to come to the shop. While we waited for her I taped up the wiring at the wing root and removed the pitot and angle of attack tubes from the left wing so they wouldn’t be in the way. I also filed a chamfer on the spar doubler to allow the spar to slide in a little easier. I sprayed a little silicone spray on the mating surfaces to help as well. Once they arrived my son Chandler helped Glenn and I to lift the wings and carry them to the fuselage. Chandler helped me align the wing root and Glenn manned the wingtip to make the required adjustments to help the wing spar slide into place keeping the bottom skin in place as well as the rear spar. Once in place I inserted the four main bolts in place. We repeated the whole process for the opposite wing. That’s all it takes and you can stand on the wings! This is a huge milestone for me and I was grinning from ear to ear. Thanks to my girl for taking photos for me. The wings are not on permanently but now I can drill the rear spar, adjust the ailerons and flaps and make the lower alumina flap fairings along with other important tasks. I will also get to work with the fiberglass wing tips, a new skill to be learned for me. For now I’m going to continue grinning and watch the SuperBowl!
So there it is! What a big deal for me to mate these two parts that have such a big amount of time between build times. I finished the wings over a year ago and now they are finally in place. Lots of work to do but days like these really drive me to work hard to achieve the end goal.
This blog post is for several days of work since it is mostly about wiring. After the last post on the start of the VP-X power connectors I finished up the remaining two connectors with all their power wires. I started by cutting and crimping all the pins in place.
I was getting a good rhythm on prepping the wires and crimping before too long. The tool that they loan out works really well and I had the remaining plugs done pretty quick.
So that finished up the power connectors so I packaged up the crimper and ran it to the post office to ship back to Vertical Power, thanks Chad Jensen for the great customer service. After getting that done I moved on to the Dynon harnesses. I will have to build one for the autopilot panel, intercom and both com units. I started with the autopilot panel and orginized the wires, labeled, cut and crimped the d-sub pins on. I followed this up with inserting the pins into the housing and put the d-sub backshell in place. I repeated these steps for each of the com units and finished their harnesses.
I decided to skip the intercom for the moment and moved on to the ADSB and transponder. Both of these have a power wire, and ground wire and two data wires that are orange and purple. These data wires are what the system uses to transmit and receive data. The Skyview screens have a 37 pin harness which has 5 sets of data transfer wires. Each is a different color with a matching purple and orange stripe. So you pick a color or port and match the orange wire from the equipment like the transponder to the colored wire that has the orange stripe and repeat with the purple. I used port #1 for the VP-X so that it can communicate with the Skyview system giving all kinds of information like how tha battery is doing and other electrical draws. Port #2 was used for the transponder and port #3 for the ADSB. Since I’m having dual screen, a 10″ and a 7″ I have to split the wires from the items, transponder, ADSB etc., to both screens so that they both receive the information. I hung the two 37pin harnesses on the back wall of the avionics area so that the length of the wires would be at a good distance to make the harness reach the screens.
Since I started with port #1 I finished up the last d-sub connector for the VP-X which houses the data wires as well.
So on to the intercom, the worst one. So for the record I am not a avionics guy and have no training on this stuff, with that said this is the hardest harness for me to build and this is why. From reading all about avionics specifically the communications parts the biggest problem is for noises to come through your headset like buzzing or static. To prevent these noises you use shielded wire, or wires that are encased with a braided cover under the white tefzel coating. This braided shield is to prevent other electronics like servos or motors from introducing noise into the communication wires. Makes sense to me that having these shields is a good thing. Here is the second thing that you have to do to prevent that noise introduction, grounding. So this shield needs to be grounded or connected to the airframe so that electrical charges can be dissipated. The biggest cause of noises in the system come from ground looping. Something new to me but the idea is that if you ground each end of a wire run there is the possibility that there is a different charge on each end of the shielding and could create a bad situation. So you leave one end ungrounded and ground the opposite one. Dynon wants you to have the ground come into the intercom and then to the ground block. So here is the fun part, I have 8 shielded wire bundles that need to be grounded. On top of that there are 6 of the wires that are inside those eight bundles that need to be grounded too. So what I have is 8 shields, 6 internal wires, a wire that will go to the pin in the d-sub and a wire that will go to the ground block that need to be connected together. This basically brings all grounds to one point and prevents any chance of ground looping. With all this chaos I had to really plan out my attack on them and figure what I wanted to do.
Here is what the block view of the d-sub looks like from the manual. You can see my chicken scratch on it helping me to understand what I was doing.
I used solder sleeves, like I have in the past, to terminate the shielding. I used one wire to figure out the best length for the harness and cut the wire. I then measured back 3″ to and removed that covering, trimmed the shielding and connected the solder sleeve.
So now I had the 8 shields terminated and a lead off of them. My plans was to solder these together and fold them back over so that a single wire could be added going towards the d-sub and a single wire back to the ground block. I also needed to add the 6 internal wires to tie into this bundle. I zip tied the ends together to hold them in place so I could solder.
I didn’t think that my solder iron would heat up this large bundle so I used my small torch to heat the wires and solder them. I added the wire that will go to the d-sub pin, each time I added wires I used a strand of wire to wrap around the bundle to hold them in place and just soldered over it.
Now that I had all the shield wires, the ground wire and the pin wire soldered I needed to add the 6 wires from inside the shielded wires. These wires are directed towards the d-sub connector so they needed to be bent back to be able to connect to the soldered part, and I didn’t forget the heat shrink before soldering them.
So now I had all 23 wires completed with their pins installed and needed to insert them into the d-sub housing. Before doing that I slid a large piece of heat shrink over all the wires to finish them off when done.
I then spent some time straightening out the wires so they looked good and zip tied the harness and added the backshelll.
So that was a very tough harness to make and took a lot of thought and planning. I’m real happy with how it turned out and think that it will work just fine. I would say I’m probably 85% done with my wiring which makes me happy thinking that all I need to do is screw in the avionics and connect these harnesses and I will be good to go, keeping my fingers crossed as I say that. I few more items left for me to then I’m off to connecting the wings to the fuselage which is a really cool thought.
I recieved the loaner crimpers from Chad at Verticle Power this weekend. So I decided to start the work for the power connectors so that I could get them back to him as soon as possible. These crimpers have a slot for the pins to slide into to hold it into perfect position. Once in position there is a sliding do-hicky that come down from the top to limit the wire that’s being inserted from going in to far.
Here is what the pins look like out and inserted into the crimpers.
Here’s the wire stop do-hicky lowered. So with the basics down, Vertical Power has a pretty good instruction manual, I started with the J8 power connector. There are three connectors that use this type of pin, J8 (8 pins), J10 (10 pins) and J12 ( yep 12 pins). The process is fairly straight forward as long as you follow their instructions. After crimping the insertion is done by aligning a little tab on the back of the pin to a notch next to the hole you are inserting it in. This is different from the other Molex connectors I have done which don’t require alignment during insertion. I figured out a good final length that I wanted for the harness. One that made sure I could reach the VP-X as well as giving me plenty of slack to install and move things around. Keeping my fingers crossed that when the day comes to install the VP-X I will have measured correctly.
Once I had all 8 pins done I cleaned up all the wires and zip tied them to create a nice harness.
It definitely helps to clean up all the wires in this side of the space. Now off to the other two connectors.
I had shipped my blank instrument panel up to SteinAir in Minnesota a couple of weeks ago to have them cut out the avionics on their CNC machine. It had arrived back this week and I had forgot to blog about it. They have all the avionics dimensions saved and can configure your panel any way you want. The benefit to having them cut out all the holes is that they also cut all the screw and rivet holes. My configuration has the two radios, intercom and autopilot panel very close to each other. There are four nutplates for each off them which means there are a lot of holes. I cleaned up all the edges and holes before countersinking for the rivets. After that work was done I temporarily screwed it in place. This will now give me the correct placement and length of the harnesses I will build.
So the idea is that after I have all the harnesses built and I buy the avionics I will be able to screw them in place and attach the harnesses and I will be good to go.
Had a great day in the shop today working on several tasks. First up was to rivet the two spar caps on so that I could put the consoles in place after finishing the wiring. These caps get blind riveted in place since you can’t get to the back side with them in place.
On the left side I added the two support brackets for the throttle quadrant.
With the caps in place I grabbed the left side console and worked on the wiring for the smoke system.
With as much of the wiring complete on the switches I put the console in place along with the throttle quadrant. I fished all the wires from the switches into the gear tower and up behind the panel.
There were a few wires that needed to be made for the smoke system to be complete.
I moved on to the right side console. The back of the panel area is getting to be a serious plate of spaghetti.
I figured now is a good time to start cleaning it up before I move on to another task. To do this i’m going to start building up all the wiring harness ends. I’m starting with the VP-X switch d-sub connector. This connector houses all the inputs from the switches on the consoles. It also has the flap control inputs from the pilots grip. An input from the starter contactor to allow a signal when the starter is engaged for an annunciation on instrument panel.
About eight more harnesses left to do to clean this area up. A lot of work done today and great progress. I also shipped out my pilot grip back to Tosten manufacturing to have a switch changed. On my flaps I had a switch that was off in the middle, momentary (spring loaded) in the down position and always on in the up position. This switch is designated like this (on)-off-on. With the VP-X you don’t want a switch that stays in the on position as it will continue to send power to the flap motor and you will get a runaway fault. Instead you need a momentary on both sides of the off position, (on)-off-(on). I emailed Tosten and they said send it and they would replace for free just pay the shipping. Great customer service for sure.
So there it is! What a big deal for me to mate these two parts that have such a big amount of time between build times. I finished the wings over a year ago and now they are finally in place. Lots of work to do but days like these really drive me to work hard to achieve the end goal. 
