[RVG8tor]

I have started to cut the canopy to fit (getting it to lay down on roll bar). It is till not there and I am getting close to the red reference line that came drawn on the canopy. I am not really clear on the instructions so hopefully someone out there can shed some light, I know that are repeat offenders out there.

The fore aft position of the canopy: There is a dimension 3 1/4 given in the plans as measured from the aft bulkhead of the baggage compartment, but is this static? On my iterations of cutting only 2 so far, if I cut some off the front I reposition the front of the canopy on this reference mark. Am I doing this wrong, should I pick a for aft positing and the leave it the and then keep cutting to bring the canopy down? I know clamping the side will change the shape but right now I can only get the forward side clamped, there is too much tension to try and clamp the aft sides in.

The plans lead you to believe that the red reference line is a line you don't want to cut past, but that line does not seem for follow the contour of the fuselage in the front. I have marked my cut line by running a marker along the fuselage which transfers the shape to the canopy.

Thanks for any help.

 

[jthocker]

Mike,
You're doing it right. As I recall I came very close to that red line, if not above it. The 3 1/4 in line probably isn't etched in stone, but I recall moving the canopy to meet it each time. You might have an exceptionally tall bubble. If that were the case you'd probably have to move that 3 1/4 line back towards the roll bar in order for the windscreen to rest on the roll bar. You can't really screw it up if you maintain enough length to cover the very aft canopy bow, and you don't' trim the sides except for notching around the side skirt vertical attach tubes. Also you'll need a gazillion spring clamps to hold the canopy along the sides. It will seem like alot of pressure is needed at the aft area, but as you work from fore to aft, it will all work out.

Good luck,

 

[RVG8tor]

Tall bubble

Jon,

I think I must have the tall bubble, I am nearly to the red guide line and the canopy is still 1.5 inches from the roll bar, and the aft red guide line is aft of the frame by 2 inches. I guess I will keep whittling away, I guess as I trim the front the aft end will keep moving forward. This is more nerve racking than anything, I just don't want the Aw S*#@ moment when I realized I cut too much.

Cheers

Mike,
You're doing it right. As I recall I came very close to that red line, if not above it. The 3 1/4 in line probably isn't etched in stone, but I recall moving the canopy to meet it each time. You might have an exceptionally tall bubble. If that were the case you'd probably have to move that 3 1/4 line back towards the roll bar in order for the windscreen to rest on the roll bar. You can't really screw it up if you maintain enough length to cover the very aft canopy bow, and you don't' trim the sides except for notching around the side skirt vertical attach tubes. Also you'll need a gazillion spring clamps to hold the canopy along the sides. It will seem like alot of pressure is needed at the aft area, but as you work from fore to aft, it will all work out.

Good luck,

 

[APACHE 56]

Mike, Sounds like...

you are right on track. I cut mine around Christmas time and did notice that the leading edge of the windscreen migrated back from the "3 1/4"" call out. Many little cuts as you've no doubt read several times on these pages. It was somewhat cool (by Florida standards) when I made the cut and drill routine. Since I've done a couple of canopies for my Skybolt I wasn't to concerned with the dreaded cracking threat. Watch that you don't impose any stress risers on the canopy and you'll be ok. You're not really cutting it anyway, rather, you're burning your way thru the plastic. As an aside I'm using a combination of mecahical fasterners and Sika. It appears from the many posts that both methods are most adequate. I reasoned though that the Sika applied as a fillet along with the rivets would act as somewhat of a shock absorber/point stress reliever.
Silly rationale? Maybe... I still draw lines on the sectional with 5 minute tic marks even thought there's a fancy GPS starting me in the face. What's that phrase regarding "old dogs..."
Don