Today I went through more epoxy than I have since gluing the spar caps. After some sanding and test fitting, I pre-glued the wing wall structure and the two plywood skins. Then Stu helped me clamp the edges down, and pinned down any spots that weren’t firmly in place.
As planned, I used some scrap lumber to make clamping bars. I used strips of geodetic material between them and the skins to ensure good pressure and clamped everything together with bar clamps.
With some epoxy left over, I glued the nose spar onto the aileron and did a little more corner blocking on the wingtip bow supports. With all that clamped, pinned, and taped in place it was time for lunch!
Today I located and temporarily screwed the bearing blocks in, and cut the aileron free from the wing.
With that done, I decided to have another look at the wing walk situation. I don’t know why the support bits were the way they were, but I decided to just get on with making them work. When I look at the plans, especially the oblique view, indicate that the parts may have been cut in an attempt to match a much earlier version of the wing without much of the reinforcement at the main spar root. Anyway… Two of them had the aft end cut well enough to work at the rear spar. The inboard support needed to be trimmed at both ends. All had to be modified to fit the main spar.
In the end I got all three to fit, though I’m not terribly thrilled with the lack of good options for supporting and blocking the ends.
Next up were the notches for the cross braces. Most were too shallow and look to have been cut out with an end mill or router; the corners were rounded. I used a file to square up the corners and deepen the notches to fit the 1/2 x 3/4 pieces.
I figure I’ve got another hour or so of work to get all of the blocking and support in place before mixing epoxy. Probably more; I still haven’t figured out what I’m going to do about the extension of the walk forward of the main spar. If I build it to plans I’ll need to remove or hack up the first false rib. And of course the plywood pieces require significant modification.
On the bright side, the plywood skin for the wing walk curves nicely and won’t be a problem to get glued down. I’d been worried about that, and had visions of needing to make my own laminated piece there, but it’s fine.
Today I went over and flipped the wing right side up, which is pretty easy to do with that nice big curved handle on one end. I cut and glued in the same bracing I did the other day, this time on the top side of the wing. It went pretty quickly.
Tomorrow I’m hoping to get the torque tube bearing blocks screwed in place and cut the aileron free from the wing. We’ll see how that goes.
This morning I woke up early and couldn’t get back to sleep, so I headed over to get a little work done. I glued and clamped the aileron end plates (CW34) in place, along with the corner blocking for them. I also did a little work shaving off some of the excess plywood and corner blocking on the wingtip bow. I’ll probably just have to switch to some low-grit sandpaper to get that job done. I’d really like to get the plywood gussets cut and glued in — oh, wait, there’s more bracing for the wingtip bows to be done…
This afternoon I figured that after 8 hours or so it was safe to move on. I made another trip over and cut and installed the CW40 plywood stiffeners for the aileron and each end of the aileron bay. Then I cut and glued in supports for the wingtip bow. All of this is just the bottom side — since the wing is upside down. I’ll do the top side once I flip the wing back over, which will likely be tomorrow.
Getting two work sessions per day in could really speed things up. I think I’ll try and do more of that. I’m not thrilled with the fact that I seem to be averaging only three days a week working on this — I need to get a fire lit under things, figuratively speaking.
I may be taking too cautious of an approach here, but I really don’t want to have to do a lot of work on the aileron ends like I did on the first one. carefully measured and cut the trailing edge so I could put the CW34 aileron end plates in place. Then, with the CW34s clamped in to make sure the edges lined up with the ends of the aileron spar, I lined up and glued in the pairs of CW35 pieces on each end of the aileron. I have the AL tubing in place to keep everything perfectly aligned.
I’ll probably go back and glue in the CW34s later on tonight. I probably should have just done it this morning. I get a little paranoid about this part of the process, since I’ve had to adjust or re-cut most of the holes for the torque tube.
Getting the CW35 aileron nose ribs located perfectly in the aileron is critical to making sure the aileron is straight and consistent with the other wing. Today I slid the torque tube into place and checked the fit of all the pieces that I can at this point. After making some adjustments to the holes in the CW36 end plates, I glued the three CW35s in place in the middle of the aileron. The next step will require cutting the trailing edge to install the aileron end caps, so I want to make sure the torque tube location is easily and consistently reproducible.
I think at this point I may just bolt the torque tube bearings in place (I have a set of 3D printed temporary pieces) and cut the last piece of AL tubing in half. This will let me work with a much shorter and easier to handle piece of tubing while setting up the ailerons.
On the first wing I built, I had the aileron pretty much finished before realizing that I’d left out a bunch of corner blocking. It was a real PITA to add it in after the fact! So this time I paid more attention. Today I cut and glued in all (I think) of the corner blocking for the parts I have done. MUCH easier this way!!
Today I flipped the wing over and got the lower aileron spar caps glued in. I also glued and clamped the CW36 end plates, and a couple of the CW32 aileron nose ribs.
I also drilled the holes in all of the remaining CW32 parts. I may need to cut a couple more of those; it looks like I’ll come up short for the upper wings. I’ll check the crate to see if they got loose and are hiding somewhere, but it’s not a big deal – I have the plywood to make them.
Today I got the aileron spar web cut and glued in, along with the top pieces of 1/4″ spar cap. I couldn’t get to the bottom side to clamp those pieces without some significant effort, so I left those for the next session. I also got the CW32 pieces cut and sanded to fit between the rib caps. I trimmed and clamped the CW36 and CW34 pieces in place to locate the aileron torque tube, then marked the CW32 pieces for the holes that will need to be drilled for the torque tube.
The wingtip is nice and solidly in place, so now I just need to sand the blocking and trailing edge flush so I can start installing the gussets and additional bracing.
This time around I plan to NOT screw up the same way I did the first aileron, by assuming that the holes in ANY of the parts are drilled in the proper place. As I did before, I’ll index everything off of the CW34 parts, using those to locate the torque tube, and drill or sand everything else to match them. And of course I’ve already 3D printed a pair of torque tube bearing blocks for this wing. The final parts will be milled out of UHMW or something similar, not 3D printed, but these are great for getting all the holes located without the risk of messing up a flight part.
The more I use it, the more I like my little razor plane. This thing was bought back in the 70s, I think, by my father for use on R/C airplanes that we (mostly he) built in our basement, usually from scratch. It’s a plastic body with a blade that resembled a heavy duty, oversized razor blade. The key thing I found was to use light passes, and hold the plane at an angle to the wood. It’s quite effective for shaving down spruce, plywood, and even the odd bit of end grain. It’s usually quicker than sanding.
Today I got the end nose rib notched and the wingtip glued in place. I have the blocking at the spar tips and nose rib, but will still need to block and shape the trailing edge as well as gluing in the plywood gussets. Still, it feels good to have the wingtip on. It looks more like a wing!
I also trimmed the CW36 pieces. These go on the ribs just outside the aileron bay and hold the torque tube support bushings. As supplied they were about 3/8 too long for the inboard side, and 7/16 for the outboard side where there’s an additional thickness of plywood where the wingtip spar web overlaps. For this I just set the miter gauge on the table saw to match the angle of the piece, then set the table saw to cut off the length needed. I won’t glue those two pieces in place until after I have the rest of the aileron structure built up.
