INSTALLING THE CANOPY PAGE 7

 

Cutting the modified C-653 Cutting is complete

The two pictures above show the process of cutting the center re-enforcement on a full sized bandsaw.  I could have made the cut on my small bandsaw easy enough but I used the big one because I was already at the shop.  Notice that I cut each side in two sections.  Sometimes when cutting a long piece like this, the very length of the section being removed can interfere with the ability to cut a straight line so I generally make a cut 90 degrees to the main cut line to make the main cut easier.  

Drilling pilot holes with rivet fan Center line of frame marked with masking tape

I put a center line on the part and drilled pilot holes 2 inches apart along this line with the use of a rivet fan.  The next step was to lay a center line on the canopy frame.  The plans tell you to drill the plexiglass to the frame first.  Then they have you remove the plexiglass and back-drill the holes from the plexiglass through the C-653.  This procedure would surely work just fine but I decided to drill the C-653 first.  I had a hard time seeing my center line through the pilot holes so I put masking tape on each side of the line (above right).  When I took the photo the flash made a bizarre pattern through the plexiglass.  Anyway, the line was much easier to see through the pilot holes framed by green masking tape.    

Cutting the hole for the latch C-653 drilled and cleco'd in place

Above left is a photo of the latch mechanism hole being cut into the C-653.  At right the C-653 is cleco'd in place after all of the holes are drilled.

Yet another deviation Pattern being traced on aluminum

The reason that this canopy is on page seven of this narration is I keep coming up with more ideas and deviations that consume time.  Maybe I should return to my previous hobby which was drinking beer and watching television.  That would not be a good idea.  Besides, I am having too much fun with this.  Anyway, the left photo above shows a pattern made out of construction paper at the front of the canopy.  I decided to put a 3/4" aluminum strip at the forward edge of the canopy.  I know that this is going to cause a sealing problem later but I want to try it anyway.  At right above I am transferring the pattern to sheet metal.

RH strip drilled and cleco'd Modification to the hole finder

I was going to try to make the strip all one piece which would have been over 64" long.  I decided not to push my luck and made it in two sections.  Above left the right section has been drilled and cleco'd.  Above right, the left strip is in the drilling process.  My hole finder was too flexible due to its length so I modified it by drilling a hole for a cleco close to the end (arrow).  Using a hole finder is a horrible way to locate fastener hole.  I usually try to avoid the process and in hind sight I should have removed the plexiglass and back-drilled the holes. 

Entire strip cleco'd in place Windshield laid in place

After the strip was completely drilled and put in place, it looked so good that I am contemplating polishing the aluminum portions of the canopy.  It is time now for the windshield installation.  Above right is a picture of the windshield sitting in place prior to the trimming process.  This is obviously not going to be a fast process.

Layout for first cut  This is what was trimmed initially

Above left there is green masking tape adjacent to green plastic "fine line" tape.  Fine line tape is used to lay out paint stripes and will bend around corners muck easier than regular masking tape.  I laid the cut out in fine line tape and put the masking tape next to.  I cut between the tapes. In this way I did not get confused and cut on the wrong side of the tape.  Above right is the first major piece that I removed from the windshield.  There will be many more cuts to come.

More cut lay outs More scrap

Above left the windshield is laid out for another of many more cuts.  The object is to trim a little at a time.  You can always take more off but it is tough to put it back on.  I had removed the protective plastic at this point because it was loose in some areas and plexiglass dust was getting onto the backing and, well it was a mess so I took it all off.  This meant that I had to be a lot more careful but it also meant that I could see better to make the trim lines.  Above right is my mounting scrap pile.  Each piece of scrap was a cut laid out carefully and trimmed carefully. 

Left rear edge of windshield Right rear edge of windshield

When the final shape of the front of the windshield was near completion I turned my attention to the aft edge.  The left edge overlapped the canopy at the same time that the right edge had a 1/4" gap.  I am not sure that I know how that is possible but fortunately there is a solution

1/4" masking tape trim line Trim line was placed next to canopy

The photos above show a 1/4" fine-line masking tape trim line on the aft edge of the windshield (arrow).  The tape was aligned with the canopy so that when the forward edge of the tape was used as a trim line there would be a consistent gap all the way around

Making a pattern of the left lower cut line Pattern used to make right side the same

The final trim ws at the aft lower edges.  The problem was to make the two sides symmetrical.  I trimmed the left side first.  I then made a pattern of it with construction paper (above left).  I moved the patter to the right side of the windshield and used it to lay out a cut line in fine line tape (right photo above).

Alignment tape Final scrap pile...lots of cuts

Throughout the trimming process I kept these two pieces of masking tape on the windshield.  I had put them there before I separated the bubble into the canopy and the windshield sections.  Above right is a picture of all of the scrap pieces from all of the cuts I made.  I think that I made about twenty total cuts between the canopy and the windshield.

Gap between skirt and canopy Gap removed with shrinker

Another week went by before I could get back to the canopy.  I was out of town on business.  If I could just win he lottery, I could finish this airplane.  That is enough whining..  One of the reasons that the skirts are made in two sections by Vans is to eliminate the gaps between the fastener holes (arrow above left).  I removed the gaps with the metal shrinker.  There is a picture of this tool on page 6 0n case you missed it.

Tape to mark area where gaps are Area aove side skirt after shrinking

To mark the area where the gaps were, I put tape on the skirt (above left).  Thare was agap all along the upper edge of the side skirt as well.  I gently rolled the skirt just above the frame win a soft jawed vice.  I then used a shrinker on the edge (above right),

Enlarging fastener holes The left skirt before removing the protective coating

Now comes the process of up sizing the fastener holes.  I stopped after the left aft holes were done because I am not sure what fasteners I am going to use.  The plans call out "pop" rivets but I am not sure yet.  I think that I will remove the protective coating and polish out the shrinker marks first.  The photo above right shows that the left skirt is fitting the fuselage fairly well.  I actually worked the aft edge over with the shrinker and the English wheel some more today.

Protective coating removed Polishing experiment started

I removed the protective coating from the skirts and experimented with polishing in the two photos above.  I think it will look good but I will have to wait and see.