Thursday, August 14, 2014

Thursday, August 14th, 2014 - back on the canopy

The last few weeks have been on and off with actually working on the project.

After getting the engine, I realized I was going to have to finalize some of the avionics decisions in fairly short order.  I've been waffling between the Dynon Skyview and Garmin G3X - both have engine monitor options, and whichever I chose was going to be the one.  

After spending quite a bit of time with the Garmin G3X Touch and the Skyview Touch, I had come to the conclusion that for me the Garmin Touch just wasn't going to get it.  Trying to use that dude bouncing around in turbulence just seems like a non-starter to me, even with an autopilot.  Actually, maybe more so, because an A/P will bail on you in turbulence.

However, the old portrait G3X is very nice, and the offer of a 400W GPS for $3995 was very tempting.  At the end of the day I just decided to go with Dynon - I really liked it a lot, and the more I worked with it the more I liked it.  Touch when you want to, buttons when you don't.  I like that a lot.

So having decided that I ordered the A/P servos and mounting hardware, EMS module and sensors, transponder,  GPS, ADAHARS and temperature probe and all the wiring harnesses for them.  I'll order the screen and backup battery later in the process.  I can get this stuff installed and wired and add the screen later.

I also ordered wire, a grounding block, some tools and terminals from B&C.  Ordered the ELT and some other miscellaneous items from Aircraft Spruce.
Van's got an order for a Comm antenna and an electric primer.

I'll try to post some pics of the Dynon components when I get a chance.

Once I got the engine mounted I went back to working on the canopy.

Basically I needed to finish up the aft pin blocks which hold the aft canopy frame down and closed when it's latched.  Then several pieces which make up the side skirts need to be fitted, and finally the aft skirts get fitted.

The plans recommend curving the aft skirts as much as possible before they are drilled.  below is my first shot at it.  Later on there is a picture with them very close to the correct shape.  Ends up being a lot more bend and twist than there is in this shot.

From Finish Kit
Drilled and mounted the aft pin blocks.  There is an angled pin on the light grey frame that fits into a hole drilled in the white UHMW plastic block.  The block is held in place with an aluminum u channel that is bolted to the canopy deck, the secured with #3 screws through the angle and channel.

From Finish Kit

C-791 - this guy gets drilled with some 1 1/4" holes and slotted on the bottom so it will flex enough to fit inside the canopy rails.  This will fit between the rails and the C660 side skirts and will serve to both keep them from flexing out and pull them tight against the fuselage skins.

From Finish Kit

Match drilling the C791 to the inside canopy rails.  These will get match drilled from the outside, but that's a 2 person job.  Need to wait until Becca can help.

From Finish Kit

The C660 side skirt match drilled to the canopy rail from the outside.

From Finish Kit

This gives an idea of the fit.  The fuselage is wider right at the seats to give more shoulder room, then tapers going forward.  This presents some fit challenges trying to get the skins to fit tightly against the fuse skins.

From Finish Kit
Here's the initial fit - not what we're looking for obviously.  The C791 piece will help to pull this in, but I'm going to massage it a bit before that happens.  We want this pretty tight before we try to snug it up with C791.

From Finish Kit

This is how we handle the tapered fuse problem.  The forward part of the skin (about 8.5 inches) gets trimmed to just level with the fuselage canopy deck.  When it's tilted and pulled back it just skims along over the canopy deck.

From Finish Kit

This is after massaging the fit of the skins.  Pretty good fit at this point, so I moved over to the left side.

From Finish Kit

This is the hole saw - I had been using an old Craftsman saw that I had, but it was as dull as anything, so I got this bi-metallic saw (Lenox).  These things are great.  The arbor is a quick fit toolless unit that is extremely solid and well fitting and fits a whole range of saw sizes, so you only need one of them.

From Finish Kit

Left side is a repeat of the right side, although due to it being hand made, the fit isn't exactly the same.

From Finish Kit

Forgot to take a picture of the right side slider rail, but it's similar to this.  On the aft end, you have to file down the rail some to clearance the skins.  This is because from aft to forward, the fuse tapers out to the seat position, then tapers back in again.  As you can see in the background, the seat backs are about 6 or 7 inches forward of this position.

From Finish Kit

Forward side skirt trimmed to fit canopy deck and clear sides so it doesn't drag.

From Finish Kit

Got a much better initial fit on this side, although it still isn't as good as I would like.

From Finish Kit

Becca was off, so I recruited her for about 20 minutes to help be match drill the C791s to the C660 side skirts.  Once that's done, they are pretty much locked into place and ready to rivet.

From Finish Kit

Since the side skirts were nearly done except for tweaking, it was time to do the aft skirts.  By all accounts these are the hardest, requiring a twisting curving shape in three dimensions to fit well.  Basically I used a hole finder to drill them while pulling the skin as tight as possible with one hand and drilling with the other.

From Finish Kit
Drilling progressing along the aft skirt.

From Finish Kit

This is the final shape I ended up with.  Even as twisted as it is, I still need to put in a little more curve at the bottom end.

From Finish Kit

This is after about 3 hours of working on the fit.  There are 3 slight gaps at roughly 20 degrees apart progressing along the curve.  Thankfully, I was able to get the bottom to fit really tightly.  Still needs some tweaking, but time to move to the right side.

From Finish Kit

Right side match drilled.  As always, the second time goes much better.  I got the middle two thirds fitting really well right out of the gate.  The biggest gap is at the bottom.

From Finish Kit

Forward edges trimmed to shape.  Laying out the lines for trimming the bottom edge and laying out the holes in the side skins.

From Finish Kit

Trim line for the aft skin.  The side skin actually fits under the aft skirt, I've just got it on top to lay out the lines and figure out where to trim and drill.

From Finish Kit