A Fisher Celebrity build project
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.
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.
The main and rear spars are in place, and half the ribs are glued to them. It’s tedious and intense work, so I’ll finish them up tomorrow.
I dug the CW42 and CW43 plywood pieces for the wing walk out of the crate and tried test fitting them. As with many of the kit pieces, they simply don’t fit. At all. The nose reinforcing pieces will be usable, with some trimming. The rear pieces… not so much. Once the ribs are fully secured I’ll see if they can be used at all, or if I’ll need to order some new plywood and cut new ones. At the very least, the notches for the cross braces are rounded at the bottom from being cut out with a router with a fairly large bit. I can clean those up with a band saw, but the ends are also not right by a long shot. It will take some work to figure out how or if I can use these.
All in all I’m just happy I didn’t pay full price for this “kit”. I’ve found an awful lot of pieces that, quite frankly, I’d have probably been better off making myself. But at least now I know what to expect.
This covers a couple days’ work. Yesterday we ripped the CW37 aileron bay TE stock down to 1/4” and I got that installed. Today I’ll glue in the triangular support pieces. And yes, I realized after cutting and gluing it all up that the CW37 piece is supposed to be notched for the rib caps. I’ll remember that for the next time.
I continue to be astonished at how light and strong this wing is. I can easily lift it off the bench and move it around; it can’t weigh more than 20-25# without the aileron installed.
The last thing that was really bugging me about the aileron was that the lower edge of the leading edge plywood still wasn’t glued down. I’ve got to find a better way on the next aileron, but this one had to be done so we can radius the lower edge.
Stew’s idea was to make a grooved board for the trailing edge and use that to clamp a board across the leading edge while the glue sets. He used a length of scrap cedar with a groove cut to match the angle of the TE, and we used four bar clamps to apply pressure. In hindsight – I honestly don’t know if just putting a radius on the front corner and wrapping plywood around it would be better or not. We’ll see how this works out.
In other news, Stew has his 4’ CNC machine in and working, and I’m going to put him to work cutting my torque tube bearing blocks out of some UHMWPE stock I have. Better than plywood, I think.
It’s been an on-and-off couple of weeks. I’ve had a persistent cold/bronchitis that has kept me away from the shop for days at a time. On days I do feel like working, I’ve got a house cleanup project that’s been sucking time as well.
This evening I got over to have a look at the aileron. I’m not thrilled with the plywood, to be perfectly honest, but I believe it will be OK. I re-glued a couple of the geodetic braces and glued down a couple of corners of the thin plywood that were loos and/or slightly de-laminating. I think the fabric would probably have been sufficient, but I want to make things as close to perfect as practical. I’ve got a list of things to do differently on the next three ailerons.
I got a few corner blocks installed to make sure the plywood stiffeners don’t flex or bow. The pans don’t call for them, but I’ll feel better knowing they’re there. I also got the ends of the aileron nose plywood trimmed and sanded flush with the ends of the aileron. There’s one more round of gluing to do, then I can use a router to put a radius on the lower front edge and it will be done. I did check the aileron travel; 22 degrees up and down will not be a problem.
It’s been a bit since my last update here. In the past couple of weeks we took a nice cruise vacation, and I developed a pretty severe case of bronchitis. It’s possible these two things are not unrelated; one of the risks you take to get a little Caribbean sun and salt air in the middle of winter, I guess!
I’ve been working to get the leading edge of the aileron wrapped with plywood. Honestly, at this point I can understand how someone would make the decision to scrap an aileron and start from scratch. I don’t think I’ll go quite that far, but there have been challenges. I’m adding to my “lessons learned” for the next three ailerons, that’s for sure. Part of it is just developing a process to get the ply to wrap over the pretty sharply curved top surface. This part I solved with a couple pieces of Styrofoam and some dumbbells, to effectively clamp the aileron to the bench with the ply trapped underneath. That should hopefully take care of the upper portion. The bottom edge of the top piece of ply isn’t yet glued to the structure, so I’ll have to figure that out today.
I’m really looking forward to building the next wing. I’ve learned so much while building this one that I’m pretty sure the next will take a lot less time, although I’ll have to figure out the wing walk on the next one. I talked to a guy building an RS-80 Tiger Moth the other day. He told me about improvements he’s made to his wing walk to avoid seeing the wing deflect when someone steps onto it. I’m not sure how much I’ll be able to do on mine, but he’s using carbon fiber in a substantial number of places on his build. Honestly, the wing walk is one area where I was thinking I would need to beef things up a little anyway… if you’ve met me you’ll understand why.
But, of course the devil is in the details. Every time I think I’m almost finished with this wing I am reminded of all the detail work that has yet to be done. I need to cut and install all of the bushings for the bolts; finish cutting, shaping, and drilling the various aluminum mounting brackets; cut and finish the scallops in the leading edge plywood; figure out and build the transition from leading edge to wingtip bow (most likely foam)… there’s a lot of stuff left to do, but fortunately it’s really only a few days’ work.
You think you’re about ready to perform some major step, then you step back and realize you’re not as close as you thought… I thought I was about ready to cut out the aileron, but I still had to get the bottom geodetic braces in as well as several of the plywood stiffening strips that keep the aileron bay and aileron from distorting when the fabric gets shrunk around it. Today I did that, I also got the leading edge plywood wrapped around the rest of the way and glued and clamped in place, and added the last of the wingtip reinforcements along with the gussets for all of those.
I started to shoot primer on the torque tube, but the can stopped spraying about halfway through. Super frustrating, as it’s a full can, It’s been in a cabinet in the garage for a while, so I suspect there was a chunk of unmixed solid that lodged in the valve or something. The spray tip is clear, the can is pressurized, but it refuses to spray. Bummer. I found a can of self-etch primer in another cabinet at home, so hopefully that works. I may end up with a torque tube that’s half gray and half white… oh well.
I’ve been cleaning up the Airpath compass while I wait for the new gaskets and diaphragm from Spruce. This one has a light and I didn’t want to use the incandescent bulb, and I’d already broken one of the wires anyway… so that path was blocked. I had ordered some LED bulbs from Amazon – they are commonly known as type 74 LED bulbs. The spec sheet showed they are about 0.7″ long and 0.23″ diameter. Those arrived today, and they do fit inside the bulb socket. I soldered the wires onto the new LED assembly “backwards”, or with the wires running along the body of the light so the tip goes in first and the connector end faces outward. This puts one of the three chip LEDs directly over the little red window that illuminates the compass. I had to remove about 1mm of the tail end of the lamp assembly so the little cover would close, but with that done it’s near perfect. I’ll get more pictures as soon as the paint I used to touch up the worn spots on the lamp cover is dry. The gaskets are supposed to be here on Tuesday, and I’ve got a can of mineral spirits I can use to fill it… not being willing to spend the extra money on UPS shipping for a pint or so of “compass fluid”, which from what I can tell is basically… mineral spirits.
On Monday night we got the wingtip bow put in place and corner blocked. It’s looking very much like a wing now! I also received my order of plywood from Spruce, so was able to cut and glue in the gussets for the compression struts.
Of course there is still work to be done. Some additional bracing needs to be installed for the bow, and the trailing edge will need to be sanded to match the contour of the wing trailing edge. Details, details.
Yesterday I picked up three 12′ long sections of 6061-T6 aluminum tubing. Two of these will become lower wing aileron torque tubes, and the third will become the torque tubes for the upper wings. None of that stuff does not come cheap, I’m telling you. I’ve pretty much blown my materials budget for the month. But, at least now I can continue with aileron construction – once I get back over there to the shop. My darling wife is sick and has tested positive for COVID, so I’m avoiding getting close to anyone for a while just as a general precaution. Once I know I’m not contagious I’ll get back over and get that tube cut to length and resume work.
