All Things Electrical

I've been trying to concentrate on all of the electrical items from the firewall aft. This is cool, since I am actually bolting parts on the airframe, and the piles of parts in boxes are getting smaller.

With the exception of the wiring, I have the instrument panel largely complete. The Biggies are; handheld GPS dock for my old Garmin GPSMap196, Dynon D180, ICOM A210 Com., Transponder, and RWS ECU programming panel. You will also notice about 20 pounds of switches, used to control the ignition/injection/fuel pumps. As always, click on the photo for more detail.
On the backside of the panel, you can see two fuse blocks, a couple of diode sets and a couple of switching relays.

Throughout the airframe, I've also installed the engine and battery busses and contactors, the voltage regulator and filter capacitor and the big ammeter shunt device.

Soon, I'll get some preliminary wiring done on the panel, then get it permanently installed.

The biggest challenge, right now, is sizing the batteries. My load analysis shows that I'll need about 13 amps to keep this thing in the air. To make my system redundant, I'll need a backup battery capable of delivering 13 amps for a half hour. Yeauch!

I figured out how and where they should go, I just hate adding all that weight.

Sandy said I should just eat less and get some exercise and not worry about the battery.

Now - Where was I?

Time to get back to the fun stuff. While I was waiting for the paint to dry I did get some other work in on the aft side of the firewall. Specifically, I'm working on the instrument panel, location of the batteries, and getting the fuel system in.

Because I'm using fuel injection, I will need a fuel pump to boost the fuel to about 45 psi. It is a closed loop system, meaning, the fuel is in constant circulation as it's filtered, boosted and regulated. The pump and filter package is mounted to the fuselage wall, just aft of the pilot.

I chose Walbro pumps and I have a second as a backup. Fuel leaves the header tank via the black fuel line and goes to an aft mounted 70 micron gascolator. Then through the fuel pump, through a 10 micron filter, then through the aluminium tubing to the firewall. After making the circuit around the engine, it returns back through the firewall and is delivered to the fuel pressure regulator. After the regulator, the excess fuel is dumped back into the header tank.

One of the biggest challenges was bending the aluminum tubing, especially the 1/2" stuff. It was tough even finding the right bender. Fortunately, I was again able to tap into SIU AvTech and got hold of Professor Billy Cheek. Billy used to bend tin for the Air Force and pulled me out of the deep hole I'd gotten myself into.

The photos are showing the work in progress. Click on 'em to see 'em bigger. Please excuse the dust.










Today I actually applied power to the fuel pumps and pressurized the system. For testing purposes I took it to 80 psi, but I think I will normally run it at 45 psi. The test was a great morale boost!

Painted at last, Painted at last, Thank God it's painted at Last!

I finally got all the parts back from the paint shop.



How long has it been? I think Rob came down just before the Fourth of July and that was the start. You can see it here: http://samhoskins.blogspot.com/2008/07/cascades-of-dust.html

I've already put the elevators and ailerons back on, and I'm fitting the rudder into place. I hope to get the stripes applied soon.

The paint really looks nice and the color is consistant. I guess I'm glad I stuck with it.

Free CAD drafting program

Not that this has much to do with anything, but I wanted to let you know that there is a nifty free Computer Aided Drafting program out there I have come to use and like. It's called SolidEdge2D. It has been great for me and it's free.

Why free? Their idea is to get you hooked on their 2D program, then hopefully, you will upgrade to 3D.

I use it mostly for my electrical drawings
Following Bob Nuckolls, AeroElectric Connection, I have a large page for the main power distribution, than an individual page for each component. BTW, if you don't have a copy, get one. I consider it a must-have.

A long time ago I used AutoCad. The company I used to work for used CoCreate's ME10, which was completely different and I grew accustomed to it. After I retired, I would have preferred to stay with ME10 but it was avilable for corporate use only.

I tried some versions of AutoCad but didn't really get along with them, then I came across SolidEdge2D.

They just released a new version, so I'm getting used to it now.

Paint not yet resolved.

I'm still waiting to get the rest of the parts back from the paint shop. I really need the elevators since I will be routing things around the bellcranks.

Jon Finley suggested I choose some contrasting colors.

Now what?

Quick update here. It's definitely a good news/bad news situation.



After sanding off about $700 worth of new paint, I sent my plane to a local body shop. The interesting thing was getting a plane with a 17 foot gear width onto a 16 foot trailer. It went well and we didn't have too far to go.

They mixed a single gallon of paint and used the base coat/clear coat method - standard for automotive paint shops. We brought it home and everything seemed great - until...

Until I put the cowling on. Lo and behold, the cowling was darker than the rest of the fuselage! A closer look revealed that the flight controls, spinner, wheel cover pants were also off color.

I brought Sandy out to the airport to look at it. I thought maybe she might suggest that I live with it, but she was disappointed, too.

I had the guys come out and look at it but they couldn't figure out what happened, since it was all painted from a single gallon. They called the DuPont specialist to take a look and even he couldn't figure it out.

So, how to make it right? The DuPont guy brought a nifty scanner which he placed on the fuselage, just aft of the firewall. This device calibrates the color of the existing paint. They took it back to the body shop and plugged it into the paint mixing computer. Just like that, the computer mixes the paint to match the scan.

Today I dropped off the flight controls and some other odds & ends, to be repainted. If they look right, we'll do the cowling. The good news is that the tail cone and canopy match. I know it will be fine when we're done.

On another note, I'm starting to plumb the high pressure fuel system for the electronic fuel injection.