Step 12.6, Rear window

I've been reluctant to install the rear window until now, because of the extreme utility of reaching through the open window to work in the baggage area.  I recently did a test fit of all of the interior components because I knew that some would require trimming and adjustment.  Some of these were in the baggage compartment which is a very small space.  Alas, with that final bit of work behind the seats done, it is now time to glue that window in.

I put the rough cut window on the plane and trimmed up the forward edge so that it met the canopy. Then I had Carol get inside and I taped the window down tightly so that she could mark the inside edges of the fuselage against the window.  Using that as a guide, I set a new line parallel to the one Carol drew giving 1" overlap.

Although she seems to be content to ride back there, but there might be an issue with weight and balance, so I guess Trina will have to ride in the back instead.

The one inch overlap is marked using 1" wide tape.  I checked this three times just to make sure that I was marking the correct side of the drawn line, lest I cut the back window and inch short.  

Well, my natural instinct to do the wrong thing was thwarted this time and the cut came out beautifully.  At this point all I have left to do is sand the edges smooth and apply the glue.  The glue is a marine grade flexible adhesive that is used to attach windows to boats.  There is a primer the goes on the scuffed plastic and aluminum.  The primer is like thinned ABS plastic in look and smell, and it paints on easily.  Once the primer has set for a bit, but less than two hours, the adhesive is applied in a thin coat to both mating surfaces.  The glue is thick and has the consistency of toothpaste.  It is messy, but does not stick well to the polycarbonate window without the primer.  This is a very welcome property as I managed to get excess glue on the window in various places and it rubs right off.

Clamps all around the roll bar and sticks cut to length on the inside hold the window in place.

And there is it is.  One step closer to completion.

Meanwhile, Carol is assembling the last of my PC boards.  This one was a late addition to the project when I discovered that the Ray Allen bargraph displays I used on my panel were incompatible with a Garmin/Vertical Power installation.  It seems that the Vertical Power box biases the position encoders for roll, pitch, and flaps at a level which is beyond that which the bargraph displays are designed to handle.  I had to design yet another board to intercept the signals going to the bargraph displays and re-scale them to fit. 

Naturally, I implemented a complex solution involving a micro controller and RS-232 serial port to do the work of a few resistive dividers -- `cause that's how I roll...