I started with the ADAHRS. Before taking my new one out, I wanted to run it first and see that the error still existed.
So I ran the unit and to my big surprise the OAT showed right up.
Yes, clearly early in the morning and working. I don't believe in magical healing, and I know what I saw before, so I was wondering what was different. Well, I ran the system off the power supply this time as the backup battery of the SV had let me down after two minutes into running the system. And it was a pretty cool morning for Tucson.
I decided to let the system run and prepare the work on the brakes. I had decided to bleed the brakes from the bottom up as the vacuum method was sucking air through the bleeding valve along with the oil. And because Don told me so :-)
While I was preparing that work and greeting the locals...
The OAT suddenly failed and it failed consistently. Fiddling with the plug didn't do anything just like before. It was about half an hour into continuous operation. I decided to crawl into the tailcone and see how warm the ADAHRS had become and to hook up the refurbished one to see if that was doing any better.
Yes, the failing ADAHRS was significantly warm and playing around with the plug didn't change anything. This indicates that the PCB has a crack or a back solder joint which disconnects the OAT due to thermal changes.
I hooked up the refurbished unit and connected it to the bus and the OAT probe.
Powering up the system brought he OAT reading back right away. Well, my unit had done the same so I kept the refurbished one running while re-bleeding the brakes.
Bleeding the brakes from below is much more effective and it does show that the valve leaks a bit when open as it also allows a little amount of oil to bypass it and leak on the hose. Getting the air out of the main cylinders was a bit of a struggle until we found out that all you have to do is to continuously push oil through the system while a second person is changing the attitude of that cylinder a bit by moving the rudder. That seems to allow the air to escape more easily on the top and then to get flushed into the brake reservoir.
It took a while but finally the system was clean of any air and the brakes have a rock solid feeling now!
The oiler can I used came from Amazon, it has a fixed nozzle that fits perfectly into a silicone tubing of 1/4" OD, which also perfectly fits onto the bleeding nozzle. It's not big enough to hold enough oil for flushing one side without refilling once, so maybe there's something better out there.
It's the brown can in the center of the picture if it wasn't obvious and the following picture shows the stuff I used to fill the system. It's fully synthetic brake fluid (MIL-H-83282).
By then the OAT was still showing on the SV display and this was a 1.5 hours test. So I decided to get my shiny but broken one out and the crappy looking but working unit in. I did it all working from inside the tailcone, although I considered to drill out the rivets again and to do all the mounting outside. However, I had to disconnect and re-connect the pressure lines and that had to be done from inside the cone anyway. That's why I decided to do it all from inside.
It went in nicely and everything hooked up ok. More importantly everything seemed to work fine when the SV came up. I didn't have a chance to test the airspeed indication yet but I consider ok for now - until proven broken.
So, again, my Dynon equipment out of the box had a failure rate of 33.3% as a 1/3 of the devices were broken before being used. There's no way that Dynon does a reasonable quality control at this time. With important equipment like avionics, even experimental, I just require that the devices are all tested for 24 hours under extreme conditions. Which means high humidity, and at maximum and minimum allowed ambient temperatures. This is standard practices for electronic equipment which in a case of a failure can endanger human life.
If there had been any noteworthy testing occurred with my servo and my ADAHRS, both problems should have been detected and I wouldn't have had these issues and a lot of lost time and faith.
What is even more irritating, is the lack of responsibility and the complete absence of interest in listening to my complaints that has been shown by Dynon. This is certainly not the attitude of a long-time market leader.
Outlook: I couldn't check the cable lengths today and I also didn't trial fit the canopy. So as a result these tasks are scheduled for tomorrow now.
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