Month: February 2022

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.

More
Canopy / Finishing / Fuselage / Top skin

Bonding the top skin

Been putting off bonding the top skin for some time. Was about to do it then realised I need to run another cable for the propellor pitch control. I don’t have the prop cables yet but left some space to hopefully easily thread it later on. When the top skin is fixed it seriously restrict access. Anyway, set to work with Sikaflex 295 UV, instructions say > 10C, so waited till the afternoon we hit about 12 C inside the workshop. The Sikaflex is messy stuff, it gets everywhere. Also messes up your clecos. Lots of acetone was used to clean them and everywhere else it got.

More
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.

More
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.

More
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.

More
Controls

Controls

Started the joystick and push rod control system, spent many hours making sure the rods run smoothly. 27/2/2022 – A note on making the controls run smoothly. The design used pushrods and torque tubes running on (?) plastic bushes which are self-lubricating. In fact, they run nice a smoothly. The challenge is that any misalignment of either torque tube (especially in the elevator controls) horizontally or vertically, a fraction of a millimetre will cause the bearings to bind and ruin the smooth flow of the controls, especially the elevator. I spent many many hours carefully aligning and removing fractions of mm from the torque tube clamps in the centre and rear. In addition, when it was all finished I found that I had not fitted the fixing collars on the front control tubes (see pic above) close enough so there was some slop in the elevator. Hey ho, take it apart again and redo it! Now it’s running beautifully, I am very happy with the result of many days’ work. I asked the factory for guidance on the pull force that’s acceptable, they are yet to get back to me.

More