Finishing Kit

February 19, 2012

Installing the Hydraulic Lift Struts - 3.0 hrs.

Next on the list of never-ending details for this canopy, is the installation of the hydraulic lift struts. Now that I have the little ball stud mounts and spacers final-painted, it's time to drill and install them. Once again, I wanted to get this done before Sika'ing the canopy in place, in case I have any significant fit issues of some kind. I have to admit it was a bit nerve-wracking to drill into my nice anodized side rails. This is another one of those areas that's highly visible and extremely difficult to replace if you mess up, so I really took my time and measured several times and marked the spot to make sure I had it right. You know the old saying "measure 3 times, drill once!" So I made two sharpie marks. Don't worry about the marks in the picture... the side rails are currently covered with clear packaging tape to protect them while I do all this canopy work. So the marks won't be permanent! Drawing 49 shows 2 measurements here; one for the 9-11/16" critical minimum distance specified between the ball studs, and 6-1/8" from the forward edge of the side rail to the aft ball stud. The two ways of measuring differ by about 1/8". The forward mark is the critical one, so I decided to split the difference and mount it in the middle between the 2 marks. It's only 1/16" beyond the minimum.

Once drilled, the hardest part is figuring out how to get washers and nuts on the screws, underneath and inside the side rail. I've noticed that some builders install platenuts here for this very reason, but it seems to me that that would be even more difficult now that the side rail is riveted in place. So here's a little trick that made this very easy for me, after frustrating myself for a while first. Washer wrenches are useless here, by the way. You can't get them in here. This is so simple. I ended up putting a sticky substance on the tip of my finger. I actually used a dab of honey out of the honey jar in the kitchen. I figured it's a harmless substance, and you get to lick your fingers after you're done! The washer stays stuck to your fingertip long enough to reach under and around the bottom flange and slip it on the screw. For the nut, I held it sort of between two fingers and managed to get it in place and turn the screw to get it on. You can also see my little 5/16" open-end wrench that I was able to slip underneath to hold the nut while I tightened the screw from the outside. Once I had this method figured out, I was able to get them on without too much difficulty.

Here's the one on the left side, all finished:

And here's the right side, seen from the outside with the strut installed. Now it's time to put the canopy frame back on and see how this works.

Well, whaddya know... I finally have a tipup canopy that actually tips up! I unclecoed the top forward skin to make sure I didn't have any worries with clearance. It clears my overhead light fixture by a few inches. Just right.

Here are a few more pictures. I feel like this is a significant milestone. I like it! By the way, my panel doesn't have instruments yet, those are just images taped on for inspiration and future planning/thinking.

The struts work great! You want to hold onto the canopy frame carefully while raising it up if you do this. Without the weight of the canopy in place, it wants to shoot up way too fast!

My enthusiasm was quickly dampened, however. I noticed after my initial excitement that the fit of everything has suddenly changed. The first thing I noticed is this annoying gap under the forward canopy skin on the right side. Further investigation shows that it not only sits up a bit higher, but it has been pushed forward, apparently by the pressure from the canopy lift struts.

On the aft end, you can see how the gap between the side skirt and the fuselage skin behind it has suddenly opened up. What was once less than 1/32" has now become almost 3/16". This is totally frustrating! After all my careful fitting and work, it comes down to this? I've heard several people complain that after all their careful work on their canopy, when they finished it it didn't fit right and everything suddenly changed. This must be what they were talking about.

I saw some examples online of people who installed some kind of forward canopy stop, ahead of the sub-panel. I was hoping that I wouldn't have to bother, but it looks like I'm going to have to look into it now. Will this canopy EVER get finished?

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