Archive for September, 2013

Classic Aero Interior Arrives – 1.5 hr

September 30, 2013 Leave a comment

Monday Sep 30, 2013

Today the Classic Aero seats and interior package I ordered nearly four months ago arrived in three boxes. This is not the cheapest way to build an RV-7A but a nice leather interior really adds to the comfort and appearance of the airplane. Being a week night I did not have time to fully install all the components but I did get to check fit each piece and get a feel for how it will look when it is done. Wow! Even in my relatively poorly lit garage the interior of the airplane was transformed. Click on the pictures to see a larger view.


I had to get in and pretend I was flying. The seats are quite comfortable and I had close to 2 inches of head clearance to the bubble even though I am 6’2″. This is going to be one sweet ride. And the smell of new leather just tops it off.


I still need to order the front carpet. Luke at Classic Aero told me to get the seats in first, set the rudder pedal location and measure the distance my heals hit the floor from the firewall so the rubber reinforced heal pad can be located for best fit. Then order the carpet. So that will be my plan.

Categories: Last 10 Percent

Mostly Pulling Wires – 8 hrs

September 29, 2013 Leave a comment

Sunday, Sep 29, 2013

This weekend I continued to work on electrical wiring challenges – mostly pulling wires through conduit and snap bushings for various systems. I started by making a new cable from the roll autopilot servo connector at the wing root into the fuselage. I soldered the wires to the plug side of the seven-pin Mini-Con-X connector and added some nylon braid and shrink sleeve to provide scuff resistance in the gap between the wing and the fuselage. Here the connector is taped to the side of the skin about where it mates to the wing-mounted connector. Inside I ran the four data wires through conduit to the Dynon network hub behind the baggage compartment and the other three wires (power, ground and AP disconnect) under the seats where they will be connected with the pitch autopilot servo wires.


I drilled some holes in the vertical ribs of the firewall to attach conduit for the wire runs. I installed an Adel clamp on each side at the top to secure to conduit which I split with a razor blade. I also drilled a hole in the rib about half way down for a zip tie to anchor the conduit but I will install the zip ties later after getting all the wires installed.


Behind the baggage compartment I made another cable that starts at the pitch autopilot servo. It is attached to a tie base mounted on the top of  the floor rib.


This cable splits into two groups of wires, four data wires that go to the Dynon Network Hub and three wires (power, ground and AP disconnect) which I ran through the conduit under the baggage compartment and seats to be spliced with the roll AP servo wires. The power and ground will also run forward to the Vertical Power unit and the firewall ground block.


I seems like ages ago since I built up and fitted the aileron trim servo hardware. Today I finally installed it permanently (I hope). You can just make out the servo control arm and the two springs that bias the control sticks in this photo. It’s kinda cool that it makes the control sticks stand vertical now even without the aileron pushrods attached. You can see my pilot and copilot control sticks are also fully installed as well.


Wires are starting to accumulate through the tunnel area of the cockpit. Right now most of them are on the right side but that will change soon. There is still a lot more wiring to do.


Categories: Avionics, Wiring

Installed Connector at Wing Root – 1.5 hrs

September 24, 2013 Leave a comment

Tuesday Sep 24, 2013

When I routed the wires from the autopilot roll servo through the right wing I left a long length of wire taped to the inner wing rib for the eventual routing through the fuselage. I decided I really did not want to wait until I moved the airplane to a hanger and put the wings on to finish routing these important connections because I am discovering that the wire routing under the seats is getting complicated and I want to work it all out now rather than make the work at the hangar more complicated. I also want to minimize the amount of work necessary at the hangar because it is so much easier to work at home in the garage. So I decided to add a connector for the servo wires at the wing root. I found a small seven pin circular connector made by Switchcraft that is intended for harsh environments. It even includes an o-ring to keep moisture out. It looks perfect for the seven wires of the rolls servo. So tonight I decided to cut the excess wire at the wing root and install the connector. There is a panel mount connector with a jam nut and #20 pins which I decided to mount to the wing rib, and a plug connector that I will install on the wires from the fuselage. After I install the wings at the airport, I will only have to mate the connectors. This connector comes in two versions; one with crimp contacts and the other with solder cups. I would prefer the crimp version but the crimp tool is very expensive – too much for one or two connectors. So I opted for the solder cup version. Here is a photo of the panel mount connector soldered to the seven servo wires. I put 1/16 diameter clear shrink sleeving over each wire solder joint, then a two larger pieces of black sleeve over that.


Here is the cable completely terminated to the connector.


I made a small bracket out of .040 thick aluminum scrap to mount the panel connector to the wing rib. I also mounted a wire tie base so the wires route up and around the hole for the aileron pushrod. There is no chance of interference with the pushrod. The connector will be accessible before the wing root gap fairing is installed. Now this is much cleaner than the coil of wires I had hanging here.


Categories: Wiring

Finished Copilot’s Control Stick – 1.5 hrs

September 23, 2013 Leave a comment

Monday Sep 23, 2013

Tonight I finished assembling the copilot’s control stick including termination of the wires to D-sub contacts on an 8-inch pigtail.


Last night I potted the pin side of the molex connector inside the lower control fitting while it was plugged into the socket side which was potted into the upper tube a few weeks ago. So now all I have to do is depress the release button on the side of the fitting and extract the upper tube to physically and electrically disconnect the copilot’s stick and remove it.


Categories: Cabin Area

RF Wiring – 5 hrs

September 21, 2013 Leave a comment

Saturday Sep 21, 2013

Today was my first foray into installing RF connectors on coax cable; BNC and TNC connectors to be specific. I ordered a coax wire stripping tool a long time ago and I finally got to use it. The Paladin LC CST 1255 (ordered on Amazon) cuts the outer jacket, braid, and core insulation at the correct dimensions for the connector. If set properly it will not nick the inner core strands which is important for a strong connection. I started by practicing stripping the wire on the end of the expensive ($2.85 per foot) RG400 coax cable. On the first attempt the tool cut right through the center core. But the cutting blades are easy to adjust and after a couple more tries it made nice clean cuts without damaging the wires. Here is an example.


I referred to the videos on the EAA website for guidance on crimping the pin and collar on the BNC connectors. A very helpful resource. Using the inserts specifically designed for coax crimping I installed my first BNC connector.


This first cable is for the ADSB antenna so I measured out the length I needed and installed another BNC on the opposite end. One cable done.


The ELT unit came with an RG58 coax cable about 5 feet long. I wanted to use it but the BNC connectors would not fit through the snap bushings I wanted to use to route the cable from the antenna to the transmitter. So I cut the connector off one end of the cable, routed it through snap bushings I installed in the baggage compartment, and then installed another BNC connector on the end off the cable I had cut.  The BNC connectors I ordered are compatible with either RG400 or RG58. I strapped the cable to the pitot static line using zip ties to keep things tidy.


The Dynon transponder uses a TNC connector instead of a BNC. Why? I don’t know because the antenna on the other end of the cable uses a standard BNC connector. The bad news is the TNC connector cost $26 each instead of $1.85 for a BNC connector. So I was slightly anxious about getting it right when I installed the TNC on the RG400 cable. Errors can be expensive. The bottom line is the installation tools and process are the same for the TNC as the BNC and since I was already in a groove with terminating these connectors and it was going well I went ahead and installed the TNC. No problems seen.


After measuring the cable and installing another BNC on the antenna end I installed the new transponder and ADSB antennas in the aft fuselage. I am happy to have these done.


The Comm antenna cable runs from the antenna under the pilot’s seat to the radio which is not installed yet. So I decided to terminate the connector on the antenna end of the cable and route the rest of my RG400 cable up to the instrument panel area leaving it long for final terminate later. The antenna is fairly close to the aileron pushrod so I bought a 90 degree BNC connector from SteinAir for this location. That keeps the cable low under the pushrod. This is another fairly expensive connector ($17.50) so again I was extra careful to strip, measure, inspect and crimp the cable to the connector. When I installed it I ran a service loop aft of the antenna so it will be easier to inspect the connector or replace it if necessary. That completes all the RF connections expect the one on the radio itself.


Categories: Avionics

Pilot’s Control Stick – 6 hrs

September 20, 2013 Leave a comment

Friday Sep 20, 2013

The stock tube for the pilot’s control stick is quite long. So long in fact that the control stick with the grip attached can interfere with the throttle. That is a safety issue so I decided to cut the tube down enough to clear the throttle. I measured the dimensions of the Ray Allen G205 stick grip and based on that cut about 2.5 inches off the tube.


I drilled a hole through the tube just below the attachment to the pivot bearing for the stick grip wires to exit. I put it there to get it as close as I could to the rotation axis so the flex of the wires is minimized. I’ll put a grommet in that hole.


I have no pictures of the next few steps but I ran 26 AWG wires from the stick grip switches down through the tube exiting the grommet leaving enough wire length to pull the grip off if necessary to work on the switches. I included a piece of braided sleeving for additional scuff resistance since these wires will be flexing. Then I buzzed out all the wires and attached labels with my P-Touch label maker.


This view shows the wires as they exit the grommet.


Next I crimped D-sub pins onto the wires. I also installed a 4-40 pan head screw through the grip cap and the tube to prevent the grip from turning or the switch cap from coming off. Sorry, no photos of that process. The tube was drilled with a #43 drill and tapped 4-40. This stick is ready to install.


Categories: Uncategorized

Assembling the Panel – 3 hrs

September 15, 2013 Leave a comment

Sunday Sep 15, 2013

Some time ago I decided to have my panel CNC machined instead of punching all the holes myself. I just don’t have the tools to cut the holes cleanly and since this is going to be very visible feature I knew it would drive me crazy to have the edges around the annunciator lights and the Gemini look irregular. I chose to use for the CNC work based on some of the reviews I read on VAF.

I spent many hours laying out my panel design in AutoCad and when I was finally satisfied I sent a .dxf file to Bill Morelli at Up North Aviation. He responded promptly and gave me some good feedback on my CAD file. So I mailed my blank instrument panel to Bill while I waited for my TruTrak Gemini PFD to arrive so I could finalize a few dimensions on the CAD file. The PFD arrived on Sep 9, I made the measurements I needed and sent an updated CAD file to Bill on Sep 10th. The panel was cut on Sep 12th and it arrived back at my door on Sep 14th. That’s pretty quick turnaround.

Today I started working with the panel. Here it is simply clecoed to the cabin before installing any components. The holes and cutouts are nice and clean. It’s much more professional looking than I could achieve without buying special tools.


I started by aligning my radio stack to the cutout so I could match drill the panel to the pre-existing holes in the stack. I also drilled the panel for #6-32 nutplates around the large cutouts for the Dynon displays.


I want to make sure the top edge of the audio panel is flush to the top edges of the two Dynon EFIS frames so I loaded both displays and clamped a straight edge across the top of the displays, to which I aligned to PMA5000EX top edge, then drilled the rib holes to match.


I installed the switches, annunciator lights, 12V power adapter, USB charging ports, and ELT control panel and installed the panel back in the cabin.


For now I just put in a couple of clecos to hold the displays in place and a couple of #6-32 screws for the Gemini PFD. That is everything but the radio which is going to be a Garmin GTR 200 (I changed my previous plans to use an SL 40) and four dimmers which I have not ordered yet, but I had pilot holes drilled by Bill. After hanger flying this for a while I can tell already that I like the layout.


This view is  a peak in behind the pilot’s display. The panel area is pretty crowded here but there is plenty of space for wiring and other stuff.


Categories: Avionics