August 14, 2005
During the middle of last week, I was reading Rick & Lori Threets site, particularly the canopy bit. Rick quoted a measurement that he calculated of 1 9/32" from the top of the canopy frame rail to the bottom edge of the plexi. All I remember was thinking, “Hmmm, that’s not what I came up with.” I worked it out to be 1 21/32", but what I didn’t do was subtract the 3/8" to get to the frame rail centreline. Oh dear. Needless to say, sleeping wasn’t too easy that night. I figured then that I was 3/8" too short on the plexi along the sides.
The next day on the way home from work, I just HAD to stop by ythe hangar to see how bad the damage would be. Turns out, probably not bad at all. There’s enough material on C-759 that I can slide it up the 3/8" and still get rivets into the rail without compromising edge distances. How lucky am I? Very! That was too close a call for my liking.
Today’s task was to make a start on the windshield, maybe start the skirts and also to get the rollers welded into the frame.
First off, windshield. I started by marking out a 1"x1" grid to help figure out getting the edge of the plexi symmetrical from side to side. This took a while! I got the idea from seeing Mike doing it once on one of the many planes he’s built. I labeled the grids too, so I had an easy reference. Kind of like Battleship!
Once that was done, I put the skin on the plane, and started trimming the plexi to suit. Here’s where I got before I had to stop, since Chris, the welder showed up.
I’d spent some time double checking the the height was set correctly on the frame before we welded anything. Everything looked good. I also checked the alignment of the roller brackets to ensure that they were square with the tracks, and sandblasted the paint away from where the welds would run. Then, Chris worked his magic and welded them in position. It didn’t take him long. It probably took me longer to get ready than it did to weld it! He did a great job too. If you’re in the Detroit Metro Area, and need some welding done by a proper Certified Welder, then Chris is your man. He’s also an A&P. His contact number is 734 634-6648. Make sure you tell him where you heard about him! I sandblasted the frame after it was done to clean off some paint residue.
Once that was all done, I set about putting it all back on the plane, and started on the skirts. I needed to establish where my holes would be on the C-759 part first, since I’d be so close to the limits for edge distance and hitting the frame rail. Hence, I decided to put the C-759 on first. This goes against the plans, as they describe making the holes in the outer skirt first, which you’ll then use as a template. This is for good reason. The C-759 doesn’t bend around the canopy frame true because of the joggle in it (it actually gets a slight curvature to it), and if you’re not careful, your holes won’t run in a straight line. So, I made the end two holes, and then made all the middle holes based on the frame rail, not C-759 part.
My next task is to make my own skirts out of some fresh 0.032" sheet. I have to make my own because they need to be about 3/8" longer! Duh! I feel like such an idiot sometimes.