Flight Testing: Gremlins

Ready for a science lesson. As ferrous metals repeatedly move through Earth's magnetic fields they can become magnetic. World War II war ships would need to be degaussed (de-magnetized) to prevent setting off Nazi sea mines. They would get magnetized from moving through the earths magnetic fields. Well, as I've been flying around apparently my steel seat belt cables became magnetized. They're magnetic fields during turbulence or steep turns (therefore they were moving a lot) would result in my magnetometer being confused and I would get the error messages shown below. This took some head scratching at first to figure out what the problem was. But after taking out the seat belt cables and watching a compass go sporadic when placed next to the cables I was convinced they were the culprit to this gremlin. I replaced the steel cables with stainless steel cables and the problem was fixed. Although later tests showed that a tow bar (made of steel) placed really high in the baggage compartment can cause the same issue, so beware.

Here you can see the steel seat belt cables and their proximity to the magnetometer.

Post Catch Up and New Magnetometer Mount

It's been a while....
It has been FOUR MONTHS! since my last post. WOW. Well, I have an excuse. After I got the hangar everything started happening very quickly. The parts from the painter were almost complete and needed to be moved into the hangar. Parts were arriving from the vendors and my "deadline" date was approaching. I wanted the plane to be done and flown off before our family vacation; a trip we take every year. With all the parts I needed on hand, and the painter nearly ready to paint the fuselage, I had a lot of work to do in a small amount of time. I was also very ready for the project to be over....I was ready to fly this thing and get my life back. Late nights and long weekends....lots and lots of work happened in only a few months. The home stretch, the last big push, the most trying times of the entire build. I took pictures and recorded times as best I could, but I have to admit that a lot of work passed by and not a single picture was taken. The recorded times fell behind and I lost track. I was working too hard to keep up with it all. For that, blog readers, I apologize; but when you get to this point in your build you will understand why. So enjoy these last posts because as I write this the airplane has completed Phase 1 and we made our family trip. I will enjoy writing about the work that is now well into the past. I'm happy its over, but it was all worth it...it is an amazing airplane!

(The dates on the posts will be altered to reflect roughly when the event actually occurred, OK, back to the blog.)

New Magnetometer Mount
If you've been following along since the beginning then you know that I designed a mount for the Dynon ADAHRS then decided to change everything and install an entire Garmin system. (If you didn't know...well....now you do) With the system change I now needed to modify my ADAHRS mount into a magnetometer mount.

First, I made a plate with a large hole to mount the magnetometer. As you can see in the image I did this by drilling lots of holes around the inside perimeter of the large hole. Then started cutting away with the dremel. This worked really well and went by a lot quicker then I expected.

Here is the complete mount. A couple L-angles made a great Z-channel and my new mag mount was complete.

Installed on the old ADAHRS mount with brass screws and nuts. Despite the system change it all worked out in the end. BTW the Garmin System is awesome. No regrets.

Overhead Cable Install

It takes a lot longer to run cables then I imagined in my head. But in this particular case I had to run a lot of cables in a hard to reach place and through the center support tube which was VERY tight. I have two GPS RG-400 cables, the magnetomer wire bundle and all kinds of power and lighting wires running through the overhead.

All of the cables are tie wrapped and Adel clamped in place.

Here you can see the nylon wire wrap that protects the bundle of wires and cables that run down the center tube. I wound up having to slide the wires and cable through the tube and then install it for this to work which is why this took longer than I thought.