Chapter 8 – Rollover Assembly

Well, this will definitely be my last post for 2012 . . . it’s been a very busy year for this airplane build.  Hopefully 2013 will be just as productive!

I’ve been playing around with the design for my rollover assembly.  I’m looking to take a welding course while I’m in Tampa to focus on TIG (I already own Stick & MIG welders and have welded a fair amount) & possibly the EAA TIG welding workshop in Georgia.

In the meantime, as I mentioned I’ve been working through different designs on my rollover assembly, which I’ve included some scribblings on it below:

Chap 8 - Rollover AssemblyThis is certainly not the final design I’m sure, but it gets me moving in the right direction and thinking about it.

Happy New Years!

Chapter 22 – Electrical System

My Christmas present to myself this year was the B&C SD-8 back-up alternator that I’ll be using in Bob Nuckolls’ Z-13/8 electrical system design.

The SD-8 is mounted on the engine’s vacuum pump pad and is used as the primary source of power for the endurance bus in a two-layered electrical system, if the main alternator should fail.

Chap 22 - B&C SD-8 backup alternator

I forgot to add a picture of my (new & improved) Starter Contactor.  After a fair amount of research, and talking to some very smart electrical dudes, I’ll be using the Lamar SuperSwitch Solid State Contactor for my starter contactor.  From what I understand, these contactors were originally made for the Lancair Columbia aircraft and were apparently made in a decent quantity so that when Cessna bought the Columbia from Lancair, they swapped out the starter contactors and Lamar had a ton left over.  So Lamar basically just dumped the remaining contactors for comparatively nothing on Aircraft Spruce.  I didn’t take a pic of mine, but this is what it looks like.  BTW, I don’t think the P/N in the pic is good any more since I believe ACS sold out their stock of these contactors.

The reason behind moving to solid state is that it has no mechanical moving parts, and is significantly more efficient than traditional starter contactors at a fraction (1/3) of the weight.

Chap 22 - Starter Contactor

 

 

Instrument Panel & Rudder/Brake Pedals

Instrument Panel

Ok, since before I left Germany I have been working on my electrical system design.  I’ve read & re-read Bob Nuckolls’ book, The AeroElectric Connection, which I think most homebuilders would agree–even if they don’t use his designs–that it’s the homebuilder’s electrical Bible.

Of course much of my electrical system design is wrapped up in the instrument panel components: how much current does each component draw?  what’s my fault tolerance and mission profile?  In short, what do I need, and how many of ’em do I need to feel comfortable?  The design and warm fuzzy factor is of course different for each builder.

I spent a good few weeks researching all the options that I saw as viable solutions for my Primary EFIS, a back-up EFIS, an engine management system, back-up instruments, radios, etc.  Basically anything that would go on my instrument panel.  I built a big matrix and essentially had a run-off of just about every system out there.  I also talked to a myriad of people about their take on panel designs.  I called, e-mailed and pestered just about every vendor out there for information.  I looked at a lot of company’s stuff, and here’s a list of the main ones I focused on:

• Dynon
• GRT
• AFS
• G3X
• TruTrak
• MGL
• TCW (back-up battery system)

I may have looked at some others, but the list above was the main jist of my focus.  In my matrix, I really focused on requirements, or in other words “needs” vs. “wants.”  I also looked at current draw, weight, size, ease of use, capabilities, features, interoperability, scalability, cost, etc.  It made me take a hard look at what I thought I was going to put in, and what I COULD put in.  In the end, if you look at the initial pics I took in my project preparation, you’ll see it looks a whole lot different than the latest thoughts I have on the panel design.  I say “thoughts,” because I still have a fair amount of time before I have to buy any panel components, and technology is always changing.  So here’s the latest generic version of my panel:

Chap 22 - Instrument Panel Mock-up

As you can see, the end result of my run off and what spit out of my matrix was Grand Rapid Technologies new 10.4 inch HXr EFIS.  The “r” on the end of HX stands for remote.  It allows almost every traditional panel component: radios, transponder, audio panel, etc. to be placed behind the panel and tied into & controlled by the EFIS.  Another 2 capabilities that factored into my decision was the GRT’s Altitude-Heading-Reference-System (AHRS) box with it’s not requiring GPS input to function as designed… And GRT’s engine management system is rock solid and is the same one used in countless homebuilts.  It’s the same engine management system box, it just gets tied into the EFIS (also remotely) where it displays data graphically.  In addition, a couple of bells and whistles admittedly helped win me over as well.  I really like GRT’s HITS (Highway in the Sky) feature on their EFIS where you essentially fly through the boxes to get the plane on the ground, and their focus on IFR operations.  Finally, GRT seems to play a lot nicer with other vendors out there, so they work with a lot more 3rd party market stuff (GPS, ADS-B, Radios, etc.).

Btw, the instrument panel is covered in Chapter 22 of the plans, which is the Electrical Section.

Rudder & Brake Pedals

The Rudder Pedals are covered in Chapter 13 of the plans, Nose & Nose Gear.  The Master Brake Reservoirs were covered in the chapter on the firewall (Chapter 15) because that’s where they were originally located.

Many early builders, including Debbie Iwatate, moved the master brake cylinders off the firewall, putting them up front either on or near the rudder pedals.  Ken Miller & Dale Martin have perfected this design and sell it in a nice package as shown in the pic below.  It’s a bit expensive, and I probably could have made them myself, but time is money to me and these are nice.  Plus, Dale includes specific instructions on how to install these guys so as not to bungle anything up!  One really nice feature on these, besides getting your brake cylinders (and thus weight) off the firewall, is that they are adjustable, so you could move them farther or closer to pilots of various heights.

Chap 13 - Nose: Rudder & Brake Pedals