Archive for the ‘Canopy’ Category

More work on rollbar

Sunday, October 22nd, 2006

I cut off some of the extra unused portions of the feet of the rollbar weldment. The material still overhangs the underlying canopy deck, but at least now it's parallel instead of sticking out at a weird angle. I didn't want to cut off any more because I'd have started to get pretty close to the welds.

The underside of the aft bolt on either side of the rollbar is pretty much inaccessable behind the canopy deck flange. I guess you're supposed to get the spacer, washer, and nut onto the bolt with the one finger you can get back in there, without being able to see what you're doing. I've even heard of people supergluing the parts together and then supergluing the whole thing to their finger. I didn't want to have anything to do with that so I carved notches into the bottom flanges of the canopy decks, just bit enough to get a 7/16" socket through. Now I can easily get the parts in place and tighten the nut, and I can even see what I'm doing if I use a mirror. I'll probably eventually pop-rivet covers over these notches to keep passengers from getting their fingers caught in there.

The rollbar is perfectly square, no need for shims.

I trimmed the rollbar brace until it fit where it was supposed to go, then drilled the 1/4" bolt hole shown below. This was much harder than it sounds, because the brace tube is thick stainless steel and therefore really hard to work with. I melted one drill bit and probably dulled a few more.

I also drilled the two bolt holes that attach the bottom end of the brace to the subpanel structure (which I clecoed back into the fuselage for this exercise). Hooray for the angle drill. I will trim the excess steel later on.

With the rollbar and brace attached, it's beginning to look like a real airplane…

Started canopy

Saturday, October 21st, 2006

The first step of the slider canopy construction is to drill pilot holes for the rollbar attachment bolts in the canopy decks. I measured many times to make sure these were located correctly:

Then I made the four spacers that sit underneath the canopy decks:

As delivered, the rollbar was about 1/4" too wide to fit the fuselage. The plans suggest that all you have to do is lean on it a little bit and it will magically assume the proper shape. Yeah right… I put all my 185 pounds on this incredibly stout piece of 1" chomoly steel tubing, which is designed to hold a 1700 pound airplane up off my head if it flips over, and it didn't budge. Surprise.

So next I went to the store and bought a big c-clamp, then made this little setup to bend the rollbar to the proper size:

However, even when I bent the rollbar inwards by several inches, it would immediately spring back to its original shape when I released it from the clamps. So, I measured carefully and clamped the rollbar to some sawhorses with the correct width figured in, and then Scott came over and we heated that sucker with a pair of torches until it was dull red:

Fire good! Obviously this destroyed the powder coat on the rollbar, so I'll have to take it somewhere and have it sandblasted and refinished. That's cool, though, because I'll be able to pick a new color that better matches the rest of the interior.

After a little bit of trial and error we were able to get the (somewhat burninated) rollbar to fit the fuselage perfectly. Thanks Scott!

Here's me drilling and fitting the bolts… you don't have to hold a wrench in your mouth for this part but I guess it doesn't hurt.

Bolts (without nuts) installed. Tomorrow I'll check edge distances and cut off as much of the overhanging rollbar foot as I can, to get it out of the way and make it look nicer.