Finish Kit 3
8/7/05 6 Hours
It didn't feel like I accomplished too much today, although I was working for six hours! Oh well. I wanted to figure out starting the skirts for the sides of the canopy, so I started working through the directions to get to that point.
I removed the plexi from the frame, and made the final cuts. Then, I sanded all the edges smooth with 18- grit, then 320 grit, then 400. Once I'm happy with everything, I'll polish up the edges with some T-Cut paint cutting compound. This stuff works a treat on edges of plexi. Once the final cuts were out of the way, I dug out the centre strip that runs along the spine of the canopy and back drilled it . I was surprised to see that my holes weren't that bad as far as how wobbly a line they plotted!
Next, I countersunk all the holes. Some need to be for rivets, and some need to be for a dimpled sheet of aluminium. My countersink cage was running a bit hot after this! Then, I drilled all the hole I had made so far out to 5/32" with the plexi drill. This makes nice holes!
I also drilled all the holes out to #30 in the frame and deburred them.
Here is the canopy in place after all that was done. This is the front half showing the alignment to the roll over bar. I haven't done the height adjustment here yet.
Here's the rear half, showing the alignment to the fuselage. It came out really nice. I guess all that tweaking of the frame previously was worth while. Hopefully, I won't have to mess too much with my skirts when I come to make them.
The next task in the book was the windshield. I thought I might put the front skin on temporarily to work out the fitting, but I gave up on that idea and decide to just lay the windshield in place for now. The book wants you to do all the fitting and drilling, but it can wait until later. I'd like to have the skin in place permanently before I mess with any of this.
Here, the windshield is laid on the plane, and centred so I can adjust the height of the canopy. I forgot to take one in the closed position. Duh! Well, take my word for it, it's not bad. The fit worked out really well. I'll need some small shims in the upper corners of the windshield, but not really too much. At the top and sides where it really matters, it fits nicely.
So now I've reached a roadblock. For some reason known only to me, I want to TIG weld the roller brackets to the frame. I don't want to see all these unsightly screws in the frame. I know there's a whole slew of them running down the canopy skirts, but that's different to one going through a piece of tube. It just doesn't look good in my opinion. So, I'll be making provision to remove the rollers should the canopy ever have to come off for service. I need to find me a quality TIG welder that can do this for me. There must be one around somewhere! Then, I can get on and paint (ugh!) the frame and start on the skirts.
In the meatime, I figured out how much to cut off the latch tube to match the roll over bar, and cut it off with a tubing cutter in situ. It was about this time that I had to leave the hangar to go get some real German Schwarzwaldkuchen (Black Forest Cake) that I ordered to take to work tomorrow for my birthday, so the latch will have to wait.
8/14/05 6 Hours
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.
8/21/05 7 Hours
Today, I figured it would be a good idea to make some headway on the canopy. It's gotta be done sooner or later, so it might as well be sooner. I started by taking off the canopy and working on the tracks. They needed the rear part beveling off so the the side skirts will clear. This was pretty easy on the belt sander. Then I drilled all the holes to final size, polished the rails up, and then countersunk the holes for screws. The planes use regular dome head screws, but I wanted to neaten it up some and use flush ones. It took quite a long time to do all this. Mostly the polishing took all the time out of the day, but they do look a lot nicer now. I polished the screw heads too. Nice.
Here is the installed item.
And a close up of the inside of the track.
Today I was going to do all the final tweaking of the canopy too, so I had to do the latch. In order to complete the latch, I had to work out some bumpers for the frame to hit for canopy closing "sound quality"! My wife is an NVH (Noise Vibration Harshness) Supervisor at Ford Motor Company, so she'll appreciate this little touch. Here's what I used. Some small rubber plugs.
The next thing I did was to install the threaded rod to the rear canopy track. In order to keep this level, I had to install a small piece of angle down to where the rod would hit it. I forgot to take pictures of this though, so I'll do that tomorrow. I also tweaked the rear of the canopy a little bit to raise it slightly. It was just a tad low. Now it's almost perfect. Hopefully, spending all that time getting this right will help me out when I come to do the rear skirts.
Now all that was done, I could do the latch. Basically, it involved lots of putting it on, checking, pulling it off, filing, putting it back on, etc. etc. I swear I had it on and off about 20 times! Eventually, it was right. Not too much strain on the canopy, and a nice firm over centre. I also bent the latch arm slightly to better match the angle of the pin. This is a lousy photo.
I finished up the finish strip that runs down the spine of the canopy, so I could set the length of the latch shaft. Then, I trimmed the latch shaft down to the right length for the exterior handle. I didn't get around to drilling the handle to the latch shaft yet though, as it was time for me to go home.... Dinner was almost ready!
I went home quite happy as I feel I've accomplished quite a bit on the canopy today. Hopefully over the course of this week, I'll be able to get more of it done. The next task is going to be the rear hold down blocks. Oooo, I'm not looking forward to that!
Did anyone notice that I assembled my latch the wrong way round? I did, when I saw the picture. It was then I realised that was why I couldn't get the handle to line up straight! Duh! So, I flipped the latch over this evening, and set about polishing it. Here it is, fixed and shiny. I'm glad I didn't drill the outside handle on yesterday before my "moment of clarity".
Now that this bit is sorted, I started on the outer handle proper. I drilled the handle with a No. 40 drill in the drill press to get a pilot hole, then drilled through the tube in the assembled condition. Then I drilled to the correct sizes and tapped the handle for the screw. I didn't like the squareyness of the lever, so I did something about it. Basically, I made a lot of aluminium dust. It took ages, but it was well worth it. It's these finishing touches that make it. All this was done with a file and emery cloth.
Things were rolling along nicely this evening, so I figured I'd stay a bit longer. It was time to start the rear pin anchor blocks. Well, I've been thinking about future canopy removal (probably should've done that BEFORE welding the roller brackets in eh?!) and I figured that the best way would be to make these blocks easily removable. Since it is impossible to remove the screws that hold the nylon pieces in, the whole bracket would have to be removable. I mounted these using nutplates in the U-brackets, so the bolts are inserted from below. I know that's not the preferred way if it comes undone, but the prevailing torque from the nutplates will stop the bolt from dropping out for sure.
Here's the left side in place.
That was it for tonight. If I get to the hangar tomorrow (highly likey), I'll do the nylon blocks.