The hinges are aluminum... the pins are steal... so I removed the pins and cut the hinges one side at a time...
The plans say to position the hinges and drill/bolt the fuselage hinge half onto the longeron.. but I couldn't do that without first testing the canopy - what if I do that and then find that the canopy rubs or doesn't open correctly or are misaligned?!
So I decided to bondo both hinges on first... test the canopy open/close... then drill and bolt AFTER I confirm everything hinges well.
It would be difficult to bondo the hinges in the exact place I want them since bondo dries pretty quick - so I first slid the hinges in place (recall from the previous post that the hinge locations are set where the hardpoints are), and used hot glue gun to tack the bottom of the hinge to the longeron (the hinge half that rests on the longeron) from the outside...
With the hinges temporarily tacked in place to the longerons with hot glue, I then used a 2x1 peg to hold the canopy cracked open and placed tape to protect the hinge hoops from getting bondo...
This allowed me to mix bondo, place 3 nickel size blobs per hinge, remove the pegs... and lower the canopy onto the hinges. Before the bondo cured, I had a minute to adjust the canopy's position to get all the gaps around the perimeter perfectly even.. since the bondo cures so fast, I wasn't able to take any pictures of that... here's a pic prior to placing bondo onto the hinge and lowering the canopy onto the hinge...
A picture looking up at the canopy's bottom surface prior to mixing bondo... this is where the top hinge half will bond to... notice the hardpoints...
After lowering the canopy onto the bondo, I waited 30 minutes to make sure the bondo cured and removed the canopy from the fuselage (the hot glue gave way pretty easy)... I then placed the canopy on the bench (upside down) and removed the remnants of the hot glue... notice the hinge is bondo'd to the canopy's bottom surface...
After 30 minutes... I opened and closed the canopy a few times... perfect fit!! The hinges are exactly where they need to be! And the gaps around the canopy's frame/fuselage fit perfect!
Pic from the inside of the fuselage.. showing how both hinge halves are bondo'd on as I test the canopy's swing....
On the outside, I noticed that there was a small gap (approx 1/8") between the hinge top half and the canopy's bottom frame... at first I thought this was because the bondo got in the way between the canopy and top half of the hinge.. but I could tell from looking at the canopy's perimeter (front and aft lip) was flush with the fuselage skin... so it wasn't the bondo's fault...
I knew what needed to be done... no cutting corners! I removed the hinge from the canopy's bottom surface... sanded the surface clean... pancaked on a 1/4" layer of flox (only where the hinges go)... let it cure... then sanded the flox down to where the canopy rested perfectly onto the hinge... this took a few tries but finally got it to where it was perfect!
Since the fuselage half of the hinge was perfect... I drilled/bolted the bottom hinges onto the top longerons.... notice the countersunk screws on the hinges...
Forward hinge...
Both hinges perfectly in-line....
The aft hinge... notice the screws go through the rollover structure... the space outboard of the rollover structure (under the hinge) will get filled with flox later...
Tape to protect the hinge hoops from bondo... I placed a card in between the hinge halves to level the top half...
See... the hinge top halves are now level so that the canopy's bottom surface will rest flush...
Same process as before... 2x1 peg to crack the canopy open and allow me to dab bondo onto the hinges' top halves...
After 30 minutes, the bondo had cured... I tested the canopy again... perfect swing! This time, no gap between the hinges and the canopy!
Checking the fit at the front lip... PERFECT!
And aft lip... PERFECT!
I then removed the canopy again... by removing the hinge pins... and set it upside down on the sawhorses...
Hinge top halves bondod in place!
Drilled through the hinge's pilot holes.. and through the canopy frame...
Then countersunk the hinges...
I then removed the hinges and bondo...
Sanded the canopy's bottom surface to make sure all the bondo was gone...
Flipped the canopy over...
Notice the holes went through the frame's top surface... looking good!
Traced out the notches I needed to mill out... the plans say to keep at least 0.25" between the canopy's bottom surface and the surface of where the bolt head will rest... since my canopy frame is taller than the plans, I kept mine 0.75"...
I used a router to mill out the notch (holding the router horizontally)... this was a bit terrifying, but worked well!
Then a dremel to square up the surface where the bolt head will rest...
I then installed the top hinge half...
Looking up at the hinge on the canopy from below...
I then installed the canopy back onto the fuselage...
It was a PERFECT fit!!!
Both hinges are perfectly in-line...
Thanks to the flox fill, the canopy sits exactly where it needs to be!
Opens and closes perfectly!
Picture from the inside of the fuselage... the forward hinge...
Picture from the inside of the fuselage... the aft hinge..
Every gap is perfectly spaced! And the spline between the canopy and turtle nook is perfect!
This couldn't have turned out any better! The gaps are perfect!
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