Top wing ailerons
We got back to work on the top wings this afternoon. I fit all the aileron ribs to the aileron spars while Dad made the plywood hinge doublers for the rear spar. I got the ribs all sliding onto the aileron spars and we glued up the doublers before leaving. Next step is to drill the wing spars and aileron spars for the hardware. Then we can start building the ailerons!
I took a couple pictures, but they came out blurry. Will get more pictures next time out.
Aileron cove prep work
I've been tied up with another project for the last month or so. Progress on the Pitts has been slow.
Today I spent a couple hours at the hangar and got a little bit of work done. The corner blocks needed to be removed from the back of the rear spar on all of the original ribs. This is to make way for the aluminum cove supports and doublers. I need to draw up some patterns in CAD and then use them to make a couple router templates. I'll have more details as I work through this part.
Corner blocks
I got a couple hours of work in on the Pitts on Friday night. I cut and installed most of the triangle corner blocks around the new ribs on one upper wing tip. Not much to it, but I ran out of clamps before I could get to the other tip. I'll get the rest next time.
I have a few nose ribs to add and then we can install the new plywood leading edges on the top wing.
Ribs glued and upper tip diagonals installed
Friday night we finished up the details needed to glue up the new ribs. It was a little challenging to get them clamped up. I like using small brass nails to tack the ribs to the spars, but wasn't sure I wanted to drive nails through the edge of the plywood ribs. We got the clamps figured out and everything stayed put.
Today, we pulled all the clamps off the rib glue-up and everything looked good. I missed gluing the front of one rib, but that was fixed while gluing the diagonals. I trimmed the spars flush with the tip ribs, which makes it look much better now.
The job for tonight was to install the spruce diagonals for each wing tip on the upper wing. The last two rib bays aren't supported by drag wires, so a wood diagonal is used instead. This is a routine task and our only deviation from the original setup was to add gussets around the end of the diagonals for more surface area for the epoxy. We used a laser to make sure we had the rear spar straight. Otherwise, the aileron hinge setup could get pretty interesting. After the diagonals were correctly fit, we made the gussets out of the same material. Once we were satisfied with the setup, I epoxied it all together. Dad figured out the clamps while I made a mess with the epoxy. The tips stiffened up nicely before the epoxy was even cured.
The next step should be locating and setting up the aileron hinges. Once we're past that hurdle, the ailerons can be built.
Upper ribs done
Another productive afternoon out at the hangar. I was able to route out all the new ribs while Dad made the corner blocking we'll need later. It was the tricky set that needs to account for the wing rake angle. Before we left, I took a couple pictures with the ribs slid into place. This is pretty close to where they will be installed. The fishtails on the ribs will be trimmed down as I figure out the parts to support the aileron cove. The details haven't been worked out yet.
Upper spar extensions finished
Today I was able to finish routing the bevels on the spars for the top wing. They came out great and I'm happy to check them off the list of things to do. I also finished work on the routing template for the new ribs needed on the top wing. We tested the fit and everything looked good. I cut a rib blank out of 1/4" birch aircraft ply and routed the first rib. Five more ribs to go which should get done on Sunday. I forgot to take pictures before we left tonight. I'll get some on Sunday to show the progress.
Routing spars extensions
We had a good day today working on the top wing spars. The plywood plates have been epoxied to all the spars where the scarf joints were put together. The next step was to bevel the top and bottom of each spar extension to match the bevels on the rest of the spar inboard. We used a long steel straight edge to project the corners of the spars out to the new sections. With a little head scratching and tinkering around, we figured out a simple way to set up a fixture for a laminate trimmer to make the cuts. It took us a couple hours to get the first one laid out, setup and cut. It came out great. The remaining cuts went faster with the last taking about fifteen minutes. We should be able to complete the same thing on the other wing tip in an hour to an hour and a half. We'll try to knock that out during the next session later this week.
Here's a picture of the result. The spars are still about 3-4 inches longer than they need to be. They will get trimmed down when we locate and install the new ribs.
Slow, but progress
Things have been creeping along lately. Lots of things keeping me busy and away from building. We've finished scarfing the spar extensions for the top wing and started gluing on the plywood doublers. None of this has been difficult or taken much work, but progress is slow when we're only putting in a couple hours a week. Just have to keep on keeping on.
Top wing still going
Two of the top wing spars have been extended with two to go. Working on the Pitts has gotten bumped a couple times for other things, but I'm still eeking out some progress.
Top wing
We're still working, but I haven't had much time to post any details. I'm in the middle of scarfing the top wing spars for the tip extensions. Dad is finishing up prep work for nut plates on the fuselage for the sheet metal. Things are moving along pretty good, so blog updates have taken a back seat for the last couple weeks. I'll have more pictures and progress details posted soon.