Saturday, April 27, 2013

Continuing Work On Right Wing

Haven't posted in awhile, but I continue to work on the right wing. Pretty much everything is a repeat of the left wing, but I have avoided a couple mistakes I made and don't have to take as much time studying the instructions. I've got the main ribs all riveted to the main spar, rear spar and doubler plates riveted on, top skins and wing walk doublers ready to go, and everything but the skins ready for the outboard leading edge.

Right wing ribs going on to main spar.
 The right wing should be at the same point as the left in a couple more days work, I just need help to get all the riveting done. I should be getting the j stiffener that I need and the sealant for the tanks any day now so that I can start work on the fuel tanks. I think that I'm about half way done with the wings at this point, so should end up with about 400 hours or so of work on them.

Left wing hanging above right wing waiting for top skin rivets.

 I haven't been working as much on the weekends lately since the weather has been so good, spending more time in the outdoors. It was a very poor winter for snow, with almost nothing left below the 10,000 foot level.

Lake Sabrina

Thursday, April 11, 2013

Setting aside the left wing, working on the right.

Finally got the leading edge riveted together and onto the spar, now it really looks like a wing. I was a little worried about riveting the leading edge due to the limited access but it went together quite easily. We turned down the air pressure to the gun and I think the rivets ended up much better. The top skins aren't horrible but there is more waviness and a couple dents that are pretty much absent from the leading edge. We will definitely be using the lower pressure for skin rivets from now on.

Left wing hanging up and out of the way.

I had considered waiting until the very end to construct the fuel tanks, but have decided to follow the plans sequence instead. Building the tanks at this point will allow bolting and torquing the tank to the spar with the bottom skins off. There are plenty of access hatches in the bottom skins, but obviously access is much better with it fully open. I still haven't ordered the proseal or the j stiffener that I need, so I'll spend the next few weeks bringing the right wing up to this point. It will probably work better this way since all of the required tasks are still fresh in my mind from the left wing.
Left wing cross section at the tip.
So far I've got the very fun task of main rib prep completed, flap hinges and hinge ribs preped, aileron torque tube bracket constructed, and aileron hinges constructed. I'm working on getting the rear spar and doubler plates all ready to go. Hopefully this weekend I will be able to get all the ribs riveted to the main spar and the rear spar riveted to the ribs. Then it will be on to the top skins and the leading edge. Things are going much faster on the right wing since I don't have to spend so much time studying the plans.

Right wing spar with ribs clecoed to spar and bolts installed and torqued.

The down side to working quickly is that it just hastens the start of tank construction. Most of the build logs I've read suggest that the tanks are the hardest part of the build, or the least fun anyway. Hopefully I'll find that it isn't as bad as it seems on the surface.

Right wing rear spar.

Wednesday, April 3, 2013

Leading Edge

Been working on the left outboard leading edge this week. The inboard leading edge will be the fuel tank since the design uses a wet wing for fuel. The kit is easier than the previous Vans designs since it already has the landing light cutouts in the skin. The mounting bracket is also provided and the skins are prepunched to rivet it to the skins. 

I plan on using a pitot tube and EFIS system that provided angle of attack info so I thought about not installing the standard stall warning actuator. The weight of the unit is almost nothing though, and it was provided with the kit, so I went ahead and mounted it. It's never bad to have a backup right? Plus I would not want to try to install it later with the leading edge attached, the provided access hatch isn't that big. I waited to install the unit until I had squeezed the rivets on the splice rib and strip. That was a mistake! It took me almost an hour to fight with the cap screws and get them all the way in. The screws seem really really long, and the nut plates are formed somewhat out of round to give them a self lock. Now I have to use the warning, just so all that effort wasn't wasted.
Access hatch for stall warning actuator.
Stall warning actuator mounted to splice rib.

    I squeezed the rivets I was able to reach. The rest of the assembly is sitting on the bench until I can get some help to set the rivets. It's much easier to get good quality rivets when your not contorting yourself to reach both sides of the unit. Lee should be able to give me a hand either tomorrow or Friday.

Left outboard leading edge clecoed together and read to rivet
While I'm waiting for help riveting the leading edge, I pulled out the right wing main spar and began working on it again. I got all of the tank attach and access hatch nut plates riveted on and completed all of the countersinks on the bottom flange. I think countersinking is my least favorite task that I've had to do so far, it's incredibly boring and surprisingly tiring.

I found out that I made a mistake earlier in the build as well. The plans have to cut some pieces of J channel to serve as skin stiffeners in certain areas. You can see a piece on the left in the picture below. The kit contains 6 pieces 8' long and 4 pieces 6' long. The instructions don't give an indication on how to make your cuts, so earlier in the build I used 8' pieces to cut the main wing long stiffeners and 6' pieces to cut the main wing short stiffeners. Now I will end up short two pieces to make the tank stiffeners. I should have cut two of the short stiffeners from an 8' piece. I'll need to order a couple of 6' pieces for the tank stiffeners. I can't wait to see that shipping bill.

Looking down the leading edge, the J stiffener is sitting in the cutout in the top of the rib