Tuesday, October 16, 2018

Fuel Tank (2.5)

2.5 hours

Starting on the fuel tank...  This thing had been stashed in the garage rafters since I first took delivery so I had to go dig it out first.  I did an initial test fit installation, and found it fairly easy to install except I couldn't get it quite far enough forward for the tank stop angle to fit.

I removed the tank and sanded some of the excess flashing off around the edges with coarse sandpaper.  I'm not sure if it helped any but at least it looks a little nicer (not that anyone will ever see it).

Anyway, while the tank was out I drilled three holes for the fittings which I'll install later.  It's not on the plans (it's on the "oops fitting" instruction sheet on the Sonex website), but the larger fitting needs a 1" hole and the smaller ones need a 9/16" hole.  I used a 1" forstner bit and a 9/16" spade bit since that's what I had.  Both worked just fine on the plastic tank material.

I reinstalled the tank for another test fit.  This time I got both tank straps nice and tight, and that allowed me to scoot the tank just a bit farther forward than the last time.  Now the tank stop angle fits just right.

The last thing I did tonight was try to improve the unevenness of the front part of the glare shield.  It's very lopsided from manufacturing or shipping or whatever, but I think it can be mostly corrected.  Luckily I had two tank stop angles in my parts heap, so I will use one as a glare shield stiffener.  I measured 15" forward from the tank stop angle holes and drilled the angle to the glare shield there.  I cut the height of the angle down to 1/2" and tapered it to about 1/4" near the ends in an attempt to clear the tank.  I'll see how the clearance looks on the next test fit.  I definitely don't want it rubbing on the top of the tank, but even if I have to cut more metal off I think it'll still help.

Sunday, October 14, 2018

Windshield (10)

10 hours

This is actually several days worth of work but I didn't want to make a post for each little work session I did throughout the week.

This thing took a lot of steps to fit!

I started by just installing the windshield skirt between the side panel skins and longerons.  The plans, unusually, don't give you any dimensions or info to locate the skirt, but in the end there's really only one place it can go.  By measuring the drawing I figured out the portion of the skirt which should overlap the skin is 1" tall, which lines up the with notch in the front of the skirt that forms the flange over the firewall.  I measured an inch in from each side, drew a line, and clamped the skirt in place with the line just at the top of the skin on each side (exactly like how I started the turtledeck skin).


The plans say to first just cleco one hole on each side of the skirt, so I did that and then inserted the lexan windshield.



It quickly became clear that without the skirt cleco'd to the longerons, the windshield just pushed the side panel skins out.



I decided the only way I was going to hold everything in place while I fit the lexan part was to go ahead and cleco the skirt to the longerons on each side.  The plans don't actually specify when you're supposed to do this, but I don't think I could have completed the process without doing it at this point!



With the position of the skirt in relation to the fuselage set, the next thing was to place the windshield correctly within the skirt.  I found some good tips here that I ended up using.  I removed everything from the plane and layed it out flat, then used a bunch of cleco clamps to align the aft edges of the windshield and skirt, and center the fuel door opening.


Then I drilled and cleco'd around the fuel door plus a few holes out on either side.


Then I reinstalled everything.  I ended up having to file about 1/8" off the front of the windshield for it to go all the way forward and line up with the holes I just drilled, but that only took a few minutes.  I re-cleco'd everything I had drilled up to this point, and then started working my way out from the center at the front of the windshield, drilling one hole at a time and installing a cleco in an attempt to keep everything as tight as possible.


Once I got around the curve at the front corners of the skirt, there was a pretty large gap between the skirt and the windshield.


To try and force the windshield out to meet the skirt, I started stuffing towels between the glare shield and windshield.  I shoved them in as hard as I could, using a chunk of 1x4 board as a ram rod.  I eventually got like 20 towels crammed in there, which reduced the gap quite a bit.


I also tried squeezing the windshield downward with a couple straps, hoping it would cause it to bulge out at the sides, but I don't think this actually did much.  I got it as tight as I could, and then just continued one hole at a time, pushing the skirt into the windshield as hard as I could manage with one hand and drilling with the other.  I think in the end all the holes turned out fine.






The aft edge was the last area that needed to be figured out.  This was tricky because there were four layers that all had to line up, the skirt, windshield, windshield strap, and the machined windshield bow.  This took quite a bit of trial and error, but here's how I ended up doing it.

I concluded there was no way I'd be able to hold all four layers together in the right alignment tightly enough to drill them all at once, so I did it in stages.  I had marked the centerline of both the skirt and the windshield, and I knew the aft edges had to line up, so drilling those two parts together first was easy.  I just lined everything up, clamped them together with cleco clamps, and then drilled from the center outwards.




Next, I skipped the windshield strap for now and worked on the bow.  I marked a sharpie line across the bow at the fore-aft position where all the holes should line up, and then I drilled a pilot hole in the very center.  That allowed me to cleco the bow to the windshield at the top center and work my way out.  Since I already had the holes drilled through the windshield, I just had to line up my sharpie line on the bow under each hole and then drill through the bow.  Once I had about three clecos in, it was pretty much fixed since the bow is so rigid.  Once I made it all the way to each side I also drilled the bow to each longeron.







The final part was the windshield strap.  This is the thing that'll form the flange which the front of the canopy will sit on.  My thought was to sandwhich it between the windshield and the bow and then drill it, but I couldn't get that to work so I removed the bow.

The way I fit this piece was I marked the width of the flange across the strap (by measuring the plans since it wasn't dimensioned...), and I marked the centerline too.  Then I once again aligned the center and worked my way outwards.



This seemed to work fine, except when I was done the ends of the strap were about 1/4" above the longerons instead of right on top of them.  I realized later that this might have been why the plans said to just cleco the front...  Maybe I should have had more of the aft end of the skirt overlap with the side skins to bring the strap down.  BUT, then neither the bow nor the windshield itself would have fit underneath the skirt.  So I think this result is about as good as I could have ended up with, but we'll see how it goes up when I fit the canopy later.


Besides that concern, my method worked and all the holes still lined up when I reinstalled the bow.



I went around and updrilled everything to 1/8" EXCEPT I took the bow back out first (since it'll need smaller holes which will be tapped for #6 machine screws.


With that all done, I took everything back off the plane, deburred the holes, and put all the parts away for now.  This is another area that won't fit through the basement door attached, so I'll do the final installation later once I move to the garage.

Monday, October 8, 2018

Glare Shield Installation, part 3 (2)

2 hours

I was thinking about keeping the glare shield just clecoed on for now, but I decided having the floor removed provided enough access for anything I still needed to do, plus the clecos were in the way of the windshield, which is what I want to work on next.

So I removed the everything, deburred, and reinstalled for riveting.  While I was at it I painted the back side of the upper firewall flat black, since the corners of it will be visible from the cockpit.

I riveted the glare shield to the longerons, and I also riveted the curved angles on the front and back.  I'm leaving the panel off for now, and I'm also not riveting the upper firewall just yet, just in case I still need access to anything when I install the fuel tank later.  I put a piece of masking tape over the crevice on each side to keep debris and stuff out until the windshield goes on.  So for now at least, the glare shield is done!




Friday, September 28, 2018

Rudder Pedals (4)

4 hours

Coming back to the rudder pedals, I had the blocks built so I went ahead and installed them.  Turned out neither pair of pedals could move at all once I got them bolted in, so I had some tweaking to do.  I remembered that I was supposed to sand the powdercoating off the pedal tubes where they met the blocks, so I did that, but they were still way too tight.  The tubes measured about 1.002" in diameter, but the holes from my 1" forstner bit were only about 0.980".  I needed to enlarge the holes for it to work.

My solution was to pick up this thing from AutoZone:


I bolted the mounting blocks together, put them in the vice, and went to town on each hole with this little honing tool.  I gave it about 15 seconds on each hole, then measured the diameter.  It took probably a cumulative 5 minutes of sanding per hole, but once I got them enlarged to about 1.005" the fit seemed pretty good.  This would have taken hours to do by hand!  Finally, I used my edge deburring too to put a big chamfer on the holes that needed clearance for the welds on the pedal assemblies.



Anyway, with the blocks modified, I lubricated everything with white lithium grease and managed to get the pedals installed.  It required three hands to get everything in place and bolted, but I got it done with only two hands and some mild cursing.  They're finally in and able to move freely!


Windshield & Canopy Bows + Other Parts (2.5)

2.5 hours

Now I'm really jumping around, but a coworker lent me her rivet squeezer which I knew I'd need to set the solid rivets on the canopy bows.  The bows on the B-model are pretty nice machined parts that come in three pieces per bow.  Each joint uses two 3/16" solid flush rivets, which means these were the first solid rivets I had to do on the whole plane so far now that I think about it.  Anyway they'll be visible from the cockpit so I wanted to make sure they turned out nice.

The rivet hand-powered squeezer that I borrowed worked well, but I couldn't quite generate enough force with it to fully set the big 3/16" rivets.  It got them set far enough to hold the parts firmly together though, so I set them the rest of the way with a hammer and ground-down bolt like the method on the Sonex website.  The end result was pretty good!






Wednesday, September 26, 2018

Rudder Cable Adjusters (0.5)

0.5 hours

Getting on even more of a tangent, once I did the rudder pedal mount blocks I figured I'd just close out that plans page and crank out these little plates.


Rudder Pedal Mount Blocks (1)

1 hour

Jumping around a bit, but spending so much time near those rudder pedal mounting brackets made me want to get the pedals installed while I had access to that area.  First I had to make these blocks.  I had this nice chunk of 3/4" phenolic material, which was just enough.  


I cut out four rectangles to make the four halves I'd need, then drilled each 3/16" bolt hole so I could bolt the pairs together and make sure everything stayed lined up.


Then I hit the sides with the belt sander to smooth out the seams, and drilled the 1" holes with a forstner bit.   It made just a bit of a mess.........