Comb the Desert

It seems as though I am in an every other work day blog post cadence right now. I just didn’t have anything left by the time I got done last night (this morning) to write a blog post, so I will combine yesterday and today.

The major task for the last 2 or 3 work sessions has been tidying up the electrical install and combing wires… which leads me to one of my favorite scenes from Spaceballs… “Comb the desert!”

In seriousness, ‘comb the wires’ is an effort to make things look nicer, free up space, and make them easier to maintain. It has been a lot of work, mostly for Eric. I know he was reticent and not looking forward to cleaning up our installation. However, It is absolutely amazing how much room it seems we have now that the wires are all fastened in specific wire routings and bundles. This helps when needing access to connectors, chasing wiring, installing or removing components. The payoff will be in the years to come. But I could tell Eric was glad he went through the effort and saw the value in doing it. Here are some views of the wire routings and bundles all combed, and fastened. These photos don’t show the cleaned up relay pack wiring, but let me tell you, it looks awesome. (As it should after 3 entire work sessions.)

I should have taken some photos of the rest of the wiring coming off the avionics bay back toward the sticks as they look great too… I will try to do that for tomorrow’s update.

While we were working on tidying up the wires, we disassembled the avionics stack and put the transponder into the tray and wired the antenna. This is an RG400 coaxial cable and we wanted to run the antenna wire because if you accidentally power up the transponder without an antenna, you can do damage to the electronics. So we decided on a location for the antenna, which will be on the sidewall of the rear seat fuselage, low just behind the forward seat back. Another antenna done. Just need to bond it to the airplane.

The location for the throttle friction lock changed after all of the monkeying around with the throttle lever we had to do over the last few weeks. So a change to the pilot left side console was necessary. Plug a hole, add a new one. Love composites when you have to make a fix like that. Glob in some micro, sand smooth, done.

Somewhere along the way yesterday, we realized that we potentially had made some mistakes running wires. Important safety note, if you are wiring an airplane, make sure you are using an up to date wiring diagram when adding wires to harnesses. Weeks ago, we had made some changes to the configuration of the VPX software regarding which circuits were controlling which devices. However, we failed to transfer that new configuration to the Vertical Power online wiring diagram documentation. So when we used the online documentation to add circuits to the airplane a few days ago, we could have made a major mistake. Hooking up the laptop to the VPX gave us the information we needed. Turns out, we only had a few wires going to the wrong pins, but it could have been disastrous. Note to self, keep all documents up to date, or better yet, only use one source as a working document.

With the majority of wire combing behind us, Eric started in on new tasks for the wiring today. The big one was wiring up the rocker switches with permanent wiring. There are two circuits per switch. One is for the LED back lighting, and the second if for the switch function. With the VPX, all the switch does is provide a ground to the VPX to tell the computer to turn on a particular device. As such, the wiring is pretty simple, a daisy chain of grounds to one side of the switch which then goes to an input pin on the VPX. The daisy chain is grounded on both ends of the switch row so that if any one wire connection fails, all switches still work. These switches need to be engraved yet, but for the most part, the panel switch installation is complete.

Oh, and one benefit of accidentally breaking the plastic instrument panel proof, is that it makes a good wiring jig so that the switch wiring could all be done at the relative comfort of a workbench. That is until you forget to land a wire in the switch grouping and have to work on your head…

Greg was also here today, and he and I worked mostly on baffle and cowl fitting type stuff. We trimmed many baffle parts including the exhaust brackets.

As part of this, we put on the cowl a few times, and determined that we needed to shave down our throttle and mixture cable mount bracket. You can just barely see the hole where the lower cable used to pass through the bracket. We will have to add a new hole to retain the cable. But now the cowl will fit with ample clearance on the bracket.

In the process of installing the cowl a few times, we also located some interference on the exhaust system. We need more clearance on 3 of the 4 pipes. It will require modifying the cowl again. We have extra thickness there, but probably not enough, so we will have to change the exterior contour. But we have a plan, and it should all work out just fine.

Another thing we did was start to fasten the fiberglass pieces to the aluminum baffles. Here you can see the cylinder fin baffles cleco-ed to the aft baffle. All I need to do is drill to final size and add some nut plates. Have I said how much I hate baffles and how happy I will be when they are done? Once they are done, I can start going through and securing hoses and wires, working towards engine start.

I saved the best two photos in the last 2 days for last. We had company over today, So we had to get everything looking presentable for our after dinner show and tell. It is always nice to see things cleaned up and operational. I can’t wait until the interior is painted. I think it will look great!

3 more days off, so hopefully we make a bit more progress… lots of little details to sort out.