Category: Avionics

Avionics / Centre Console / Misc / Panel

Instrument panel first switch on

An exciting moment. The G3x immediately found (over the CAN bus) the magnetometer (GNU11) and audio panel. I initially had problems recognising the transponder. Made a software update G3x V6.0 now. Then reinstalled the config file. Then it worked fine. Flaps, inside lights, boost pump. G5 all work fine. I have never used a G3x, so I spent some time getting to know the panel and adjusting the infinite number of settings! The G3x is an awesome piece of equipment. Found couple of errors in the wiring harness. The lane B LED and Lane B switch were wrong way around. Easily fixed by re pinning the CPC connector. The wiring of the IBBS 1 and 2 battery volts monitors were not made in correct locations. Rewired D connectors to set GP3 and GP4 on the GEA24 for IBBS volts. I had to remake four loose crimp connectors at the relays. Found a loose engine sensor probe which was giving an error on the G3x. All systems seem to be working fine now. (no engine start done yet) but only error is the magnetometer calibration not done.

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Avionics / Centre Console / Harness / Interior / Lights / Wings / Wiring

Wiring

Been laying out the wiring harness through the centre console and looking to see how all the required lines will go. Especially how all the lines will go and not clash. Getting past the elevator torque tube. It’s very busy. In the centre console are: Rudder cables x2 Antenna coax x 4 placed in grey plastic flame retardant conduit Fuel lines x 4 used a 3D printed spacer for rudder cables Rudder cable x2 Wiring harness Pitot and AOA pipes Throttle cable Brake fluid header pipe Rear connections The magnetometer has to be fitted in the rear fuselage through an inspection hatch. Quite a fiddly job to do. Brass screws with locktite without dropping a screw that will rattle forever. Then fit a zip tie on the pr existing clamp provided by the factory, so that the magnetometer cable doesn’t go near the rudder cable. 28/2/2022 Tidied up the centre console wiring and added the pitot and angle of attack lines.

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Avionics

Antennas

15 Jan 2022 Learnt about doubler plates and installed the GPS antenna – well at least test fit till after painting. Used the Dremmel to repurpose the kit supplied mounting bracket, making a nice doubler plate for the GA35 GPS antenna on top of the fuselage. The transponder took a bit of sorting, needed to open up the floor in the centre channel to get access for the fixings. Another use for the laser level. :-). Factory said no need for a doubler plate on the transponder antenna, but I made a small one anyway. Also learnt about UNF and UNC fixings. It’s amazing the Garmin GA35 cost so much, and I still have to source 4 specialised UNC 8-32 nuts to fit it! The bolts you do get, but they are also special 120 degrees. The Rami AV74 transponder antenna comes with nuts.

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Avionics

Autopilot Servos

I fitted the Aileron AP servo today. Should have been a quick job. But no, was a really long job…The bracket for the servo was not factory fitted (as it should have been in QB), no matter, spent a long time getting the bracket fitted. Need to get 4 off M4 nyloc nuts fitted where you cant see under the spar and in a very narrow gap. Quite hard going inside the cockpit for several hours on this one. Then the AN3 bolts to hold the servo in place very hard to get to. All done in the end but a very slow progress day. The following day fitted the elevator servo. Again a tricky job. The last AN3 bolt was very hard to tighten, had to try all sorts of combinations of my 1/4 socket extensions and adaptors in order to get a socket that fit the depth available and the small space. Found that the elevator control stop under the console and the AP overrun ring do not align even after changing control rod length. After communication with the factory, the fix is to remove some (10 mm in my case) of the Garmin control stop ring and rotate the stop ring one screw to the right.

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Avionics / Magnetometer / Misc

Avionics rack and wiring harness install

Got started on fitting the rack today. Doubler panel. The latest offering (Jan 2022) from MWPB splits the harness into two. One for the airframe and one for the equipment rack behind the dash. It is quite overwhelming figuring out where the tentacles of these wiring harnesses go at first. Unlike the rest of the Sling kits where you have many diagrams and the parts down to every last rivet and grommet. The MWPB panel and harness no install instructions or layout diagrams other than Facebook videos. You are also on your own sourcing any extra clams and tie wraps. Two things were needed to get started. Where do the ground and power busses mount, and which wires need to go through the firewall (so that I can get that done and fix the top skin). Once I got my bearings, it become s easier. The rack behind the dash has a sub-rack that is designed to mount an audio panel transponder and second com radio. It’s white heavy (820 g) and made from 2mm aluminium. I also was concerned about accessibility to service the audio [panel after the windscreen is fitted. I could not see how it could be removed. (Whereas the transponder can be removed with screws from below). I decided to remove the sub-rack to save weight and improve serviceability.

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Avionics

Fitting the panel to dashboard

Lots of work with the Dremmel was required on my dash to open up the fibreglass/leather. Slow messy job. There is very little space below the main switches on the left. Fitted rivnuts with epoxy glue. Used pilot countersink to get an accurate position. All line up nicely. Had to remove the leather at the end to make a good fit without warping the panel.

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Avionics / Misc

Static Ports

The factory has moved the static ports to 25 mm in front of the Nacca duct. (Used to be in the rear fuselage). The ports now require a shield to be riveted around them. A kit is on its way to me. Although not essential, I wanted to get the ports installed before the top skin is fixed as it’s easier. Unfortunately the rear of the static port clashes with the Nacca duct, so I machined a little of the Nacca duct away and filed the static port to fit.

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