Control System - FCP Pod - Magnetometer Mount

Busy weekend mixed with both "real" work and "plane" work. While I had some time to slip out into the garage, I was able to finish the control system by installing all the pushrods and control sticks for a clearance check with the fuel filter and fuel lines. With the straight fittings coming out of the fuel filters, it will be "close" in certain stick positions, so I'm going to play it safe and change them out for 45-degree fittings, which should make a pretty big difference. For photo purposes, I also grabbed my Tosten stick grips and stuck them on each side to get a first rough look at what the controls will look like:

Control Sticks installed with Tosten stick grips

Closer view of sticks and stick grips-- note clearance with R fuel filter

Of course, the sticks will have to be cut down quite a ways to be the proper length with these grips, but it was still pretty cool to sit in there and move them around a bit. The "trigger" button on the grip is normally wired as the push-to-talk button, but until that actually happens, we will refer to it as the "pew-pew-pew!" button. :-)

That was pretty much it for yesterday. Today, I started making a "pod" for the GMC-307 flight control panel. The master plan is to make a panel which measures approximately 9" x 2.5" and stand it off about 1.5" from the main panel, and contour it up to the top skin of the upper forward fuselage. The panel will fit (tightly) the GMC-307 control panel, as well as a custom annunciator panel with 4-5 warning lights on either side of the FCP. You may have seen pics previously of the mockup, where the GMC-307 is hanging down from the top... this is the general idea, but now I need to build a pod that actually mounts the thing in that location.

Unfortunately I didn't take any pics of the construction process (I was "in the zone") but here's a few photos of the finished product:

GMC-307 mockup and annunciator pod clecoed together

Back side of pod that will permanently rivet to the panel (and screw into the top skin)

Pod with front panel removed

Pod partially clecoed to the main panel

That's basically the idea of it! It all seemed to go together fairly well (although it took quite a long time to build), and with some upholstery over it I think it should look pretty sharp. We'll see. A lot of this is only visible in my head for now and hasn't yet been proven to work in the real world, so lots more to come on this.

In other news, I got started on making a mount for the magnetometer. It seems the consensus for mounting location for the GMU-22 is in the tailcone, along the top stringers and near the static ports. I again found myself on Justin Twilbeck's site and read up on the method he used to fabricate his ADAHRS tray, which he later changed to a place to mount the GMU-22 instead. Taking both of his posts (original design here and GMU-22 mod here) I made a tray similar to his first design but taller and with a few other modifications. Again, I failed to take pics of the construction process but here is the final piece:

GMU-22 tailcone mount

Basically, the tray is about ~3" down from the tailcone top skin, and the tray is approximately 10.5" wide. I cut a 2-9/16" hole in one side using a fly cutter (remember there is a center stringer in the tailcone) to eventually mount the magnetometer itself. The stiffeners are installed on the top side of the tray instead of the bottom also, for better clearance with the side plates. I made it so that the side plates each have an angle piece and two #12 holes, such that the mounting plate can be slid in on top and over the angle pieces, and then bolt into place with brass hardware. This way, the relatively weak non-ferrous hardware will only be loaded in shear, and should have no trouble holding the magnetometer in place. Cool! Now just for some primer and rivet the three individual pieces together.

That's pretty much it for the weekend. More panel planning, fuel system layout, and miscellaneous "stuff" to come!