Tag: Plans

Posted on

Wing metal parts

Over the past couple of days I’ve been collecting, drilling, and prepping the aluminum wing attachment parts. These are a collection of pieces cut from 6061 and 2024 AL bar stock. They will be used to attach the wing spars to the fuselage, attach flying and landing wires, and attach the N struts, and connect the upper and lower ailerons. Each one must be cut from the raw bar stock, drilled for bolts, and some of the ends rounded. I’ll do some sort of finish to prevent corrosion. I have some Alodine left over from when I was building the RV-12; if it’s still usable I’ll use it. If not, I’ll most likely buy some.

More than once the instructions have caused a little bit of panic. For example: Yesterday I drilled all of the holes in the attachment brackets to their final quarter inch (0.250) size. I remember that I’m short some pieces, but didn’t remember which ones or how many. I’m also unsure of which ends of which brackets need to be cut and sanded round. This morning I looked at the plan revision sheets that show the drawings for the parts… and saw that the drawings call out all of the holes to be 0.1875″. Panic!! Holy moly, did I just ruin all of those parts and waste all of that work? Oh, wait. I’d made little 3D printed pieces to help mark the ends for cutting… and those have 1/4″ bosses to fit the holes, so I planned 1/4″ holes before. And a 3/16 hole would fit an AN3 bolt. I’m pretty sure the plans call for AN4 bolts everywhere, and there’s no way in hell I’d be comfortable with wings held on with AN3 bolts…

Back to the wing spar plans… Yep. AN4 bolts and 1/4″ ID bushings everywhere. The supplemental drawings are incorrect or out of date, no big surprise. Back to work.

I did manage to badly mis-drill one of the CAW9 brackets, so that’s scrap — but it really doesn’t matter in the long run. I came up a little short on the 3/16″ 2024 stock needed for some of the parts, so I’ll need to buy another 12′ length anyway. It’s an odd size that is difficult to find on line, but fortunately my local supplier can get it for me even in single piece quantity. Even they don’t list it in their catalog. Most places only carry 2024 in 1/4″ thickness or more.

After inventorying my parts I need another 60″ or so of 2024 stock, and I only have about 3′ if that. Fortunately the parts I have on hand are enough for the two lower wings, so I can cut the bushings, buy hardware, and attach all the pieces on the two wings I have built and get them finished before moving on to the upper wings.

I got over to the shop to make sure the bolt lengths called out in the plans were OK. I’m glad I did. IN each case I decided to bump the bolt up one number to get the next longer grip length; the exception was the three bolts on each wing that attach the CAW-4 landing wire brackets. Those were specified nearly half an inch short; I had to go from AN4-20A to AN4-24A to get the right grip length. I’m glad I checked. I also ordered a couple dozen standard and half-thickness AN960 washers to get everything done up right. The hardware is ordered, now I just need to get the bracket ends done and get them prepped for installation.

Posted on

Miscellaneous work

Today came and went without mixing up any glue. I sorted out the nose plywood, then went through all of the aileron pieces and got them cleaned up, marked, and re-taped for the three remaining ailerons. I got the aileron spar web and marked it for the notches to clear the ribs, then brought it home and started cutting those notches on the bandsaw. I pulled a wingtip bow down and checked its fit; it looks like minimal trimming will be needed.

I also collected all of the aluminum pieces I had at Stu’s shop and brought them home, and cut the ends on the bandsaw. They’re all CAW2 pieces, I think — I need to dig out the rest of the pieces and get them all drilled and finished off. I’ll finish them on the belt sander and Scotchbrite wheel before priming them. My little 3D printed guide button worked great for this. I don’t recall if I described it or not, but it’s just a 1″ diameter by 1/8 thick disk, with a 1/4″ diameter by 1/8 thick nub in the center. Put the little piece in a 1/4 bolt hole, and the larger piece gives you a perfect guide for shaping the end of the bracket with a 1/2″ radius. They’re disposable if you nick or break one, and only take a little while to print up. I’ll probably print a few more in case I destroy any while using the belt sander.

I spent some time trying to determine whether the wing walk pieces will be of any use to me or not. The plan sheet and plywood supports all seem to be made for some earlier version of the wing. The notches on the supports don’t work (or even come close to working) with the root blocks on the main spar or rear spar. The forward plywood bits are too long, and even if cut off don’t match the curve of the wing ribs. There are supposed to be three installed forward of the spar — but that would only work if I removed one of the false ribs. I still don’t know what I’ll do for the wing walk. I do know that 1/4 plywood for the rear portion would need some curve in it, and I’m not sure about that. The plan notes say to nail it in place until the glue dries… ::shrug:: This is why I’m considering a laminated layup with some wood and maybe a layer or two of carbon fiber.

Posted on

Wing work through 2/26

Mostly small things over the past week. I cut and installed some more corner blocking that I didn’t get done before, tested a couple new iterations of the bearing block/spacer, and fine tuned the aileron to the opening. Along the way I’ve noted a few new lessons learned…

  • Never trust the plans, or the supplemental sheets included with them. They’re often inaccurate. Like the AL bracket diagrams that call out 3/16″ holes when they will get 1/4″ AN4 bolts… and on and on.
  • Get the torque tubes in place, holes moved or enlarged where needed, and bearing blocks in place and holes drilled before cutting the ailerons from the wing. Otherwise it’s just a bitch getting everything aligned after the fact to locate the bearing blocks. This of course goes along with correcting all of the many problems with the holes that are pre-drilled in those plywood parts.
  • Make sure all of the corner blocking is installed around the aileron bay as early as possible, and certainly before installing the CW40 plywood stiffeners, aileron leading edge skin, and so on.
  • Go over the plan sheet more often and in greater detail to make sure I don’t miss anything that will be a pain to install later on… like corner blocking that would be much easier to plane or sand to shape than to try to cut to match odd angles.
  • Install the compression struts before the geodetics! That cost a couple hours of added time working through tight openings.

Not necessarily a “lesson learned”, but something I’d like to explore. All of the ribs ended up needing a 1/8 shim between the top rib cap and the main spar. Rather than shim them with separate pieces, I want to see if I can maybe cut and install the geodetics at the same time the ribs are glued, or something. Or possibly just use temporary shims, and glue the top cap to the spar as the geodetics are installed. It could lead to neater and better construction.

Posted on

Opening 2024 with an aileron

Today I hit a pretty cool milestone – I cut the first aileron free from the first wing! Pretty jazzed about that. I trimmed up the rib cap ends as much as I needed to, and glued on the lower aileron spar and the upper stringer. Lessons learned here:

  • The CW36 pieces (aileron bay end plates that hold the torque tube bearings) did indeed have the holes drilled about 1/8 or 3/16 forward of where they needed to be. Not a big deal, since those will get UHMW bearings attached to them. I did a little cutting and some sanding with a 3/4″ spindle sander drum (hand held) to get them where they needed to be.
  • The CW35 pieces (aileron end plates) have the holes drilled about 3/16″ below where they needed to be. I didn’t realize at the time exactly how the whole assembly goes together, but now I do. What this means is that CW35 on each end is too high to match the profile of the ribs. The top will need to be very carefully marked and cut or sanded to match the rib caps, and the bottom will need to be filled with some spruce or pine scrap. Lesson learned; for the other three wings I’ll re-cut those holes to match the holes in the CW34 pieces. I’ll do that by gluing up the CW34/CW35 stack with the profiles aligned; once dry I’ll use the spindle sander with a 3/4″ spindle to make the hole in CW35 match those in CW34.

The next issue to deal with will be the thickness of the CW37 pieces. The plans clearly show it as 1/4″ thick, but the supplied stock is 1/2″ thick. It’s used on the top and bottom of the aileron bay. Once I have the aileron completed – CW35 bits corrected and plywood attached – I’ll need to install the aileron with the torque tube in place and figure out exactly how to finish out the aileron bay.

Posted on

Still hacking away at it

Rear spars built, and tip supports added. Now building the tip supports for the main spars. At some point I need to get some AL stock and see if I can find my box of 4130 tubing to see if I’ve already got bushing material. Then I will need to drill the holes for the attachment and strut/wire fittings before starting wing assembly.

The spars don’t look terribly complex on the plans, but there really is a lot of detail work involved. It’s dragging on longer than I had hoped since it’s a trip over to Stu’s every time I want to get a little work done. I think I may need to take a little more structured approach to this — study the plans, then make a punch list for each trip so I don’t waste time while I’m there trying to figure out the next step.

Posted on

Spar update 10/6/23

Happy birthday to me! 🎂 This morning I glued the two lower rear spars up – webs to caps only, and set them aside to cure. That’s all four rear spars now ready for the addition of the plywood blocks for attachment brackets, flying wires, landing wires, and N struts. The cut-off pieces of 1/16 ply will make shims for the lower main spar strut/landing wire attachment points that need to be 1/8″ above the spar caps.

In the afternoon I went back over and glued in the blocks and plywood plates on the root end of the rear spars. There are other blocks and structure to be installed outboard, where the struts and wires attach, but after taking the time to figure out the plans and exactly what needs to be done it was getting too late to glue those bits up. The plans could benefit from an oblique view to better show how things go together, or at least two views of the area… but they’re old and drawn by hand, and there’s only one view. One has to hope there’s a reason that parts of it are built the way it’s shown. The blocks in the kit are oversized and will need to be trimmed, and I want to make sure I have plenty of time to make sure everything is in the right place.

Posted on

Progress, up to a point

During two working sessions today I got most of the assembly of the lower main spars complete. “Most of”, because when it came to laying out the plywood blocks for the landing wire attach points… well, after a while studying the parts and the prints and the spars, none of it makes any sense. The upper wing spars were not exactly straightforward; a few of the parts didn’t match the plans, but the end result looked correct in that the location and final layout of the blocks matches the print, even if the parts making up those blocks are a bit different. I’ll need to spend more time studying the plans for the spars, as well as the plans for the N-struts and landing wires to figure out what needs to be done.

I also ordered a gallon of T-88, hopefully I’ve got enough to last me until it gets here mid-week.

Edit: After looking at print #15 of the plans, things are quite a bit clearer. That drawing shows the flying wire, landing wire, and N-strut attachments, with part of the spars shown. Tomorrow I’ll be able to glue in the blocks for the lower main spars and, hopefully, get them finished. Well… “finished” is a relative term, I suppose. I haven’t started attaching the parts for the wingtip bow support, but I may just hold off on that for the time being.

Posted on

Generic update

Yeah, it’s been a long time, no updates, and so on. I bought a few more pieces of capstrip from ACS to finish out the last of the false ribs, but honestly the lack of any place to assemble wings or build the tail surfaces — or really any other parts of the plane — has had me less than enthused about getting much done. I’ve got a tall stack of full wing ribs and an almost-as-tall stack of false ribs sitting on a bench on my basement, doing nothing.

From time to time I check Barnstormers to see if another Celebrity pops up for sale. Occasionally one does. The two that really gnaw at me? A gorgeous, Rotec radial powered Kitplanes Magazine article centerfold that was advertised for probably less than the engine would cost me, and one a couple hours’ drive from here with no engine that was listed at about $5K or so. In both cases the timing just was not right (hell having not frozen over quite yet).

Now I’m contemplating a run down to St. Louis. The purchaser of Celebrity serial number CE165 – one later than mine – had apparently never started building, and a crate with the complete wing kit is for sale. The seller is asking a fraction of the cost of a new kit, and it appears to be complete. I did some plotting, and even just ordering the wood for the wing spars – not the entire wings, mind you, just the spars — would cost more than he’s asking plus my gas for the trip, and that’s before I pay LTL freight costs to have it shipped from Aircraft Spruce. Plus it’s a complete wing kit, with all the pre-cut plywood pieces, laminating strips for the wingtip bows, trailing edge pieces, all of the bits that would add cost and time and aggravation to a scratch build. I can’t pass it up. I’d also have a full set of plans that I could sell to help defray a little of the cost.

A friend with a large woodworking shop has offered to let me continue building there in his shop — heated, air conditioned, lots of space, plenty of power tools, and this all feels almost too good to be true. I’ve just got to make a 13-14 hour round trip with a pocket full of cash.

Stay tuned, I guess.

Posted on

Musing.

Haven’t done much in the past few days, mostly because I’ve had the workbench cleared off to fix a recalcitrant robot vacuum.  I did unroll some of the plans and take a good long look at the tail surface sheet.  Sixteen feet or so of paper, mind you…  not the easiest thing to manage on a 6′ countertop!  I wish that had been split into two sheets. 

It looks like I can build the entire fin and rudder out of pine and plywood, so that’s my next project, I think.  I’ll go look for a suitable 10′ length of pine at Menard’s that can be ripped down into decent quality lamination strips.  Once the saw is set up for that I’ll make as many as I can, since I’ll have a bunch of other laminations to do as well for the wingtips and fuelage.  Then I’ll look at what to do for the elevator and stabilizer spars. 

Posted on

Slow progress

I’ve knocked out a few more aileron ribs, two at a time.  I’m about halfway through them and trying to speed things up a little, so I don’t die of old age with a half finished airplane.

Yesterday I decided to use up a piece of obviously bad capstrip Aircraft Spruce saw fit to ship me.  This piece has a large chunk missing out of one edge, part of a knothole or pitch pocket or something.  Part of it is in no way suitable for aircraft use or much else for that matter.  But – there’s enough good wood there to use it for false ribs, so I made one of those.  That went OK, but it’s apparent that I will need to soak the top capstrip in HOT water for the false ribs.

I’m looking forward to starting work on the tail surfaces.  I’m planning to get out to the garage and clear off the workbench this week, lay out the plans and see exactly what I will need to get started.  The wood called out is white pine, so I’ll start checking the local places for suitable pieces of white pine or Douglas fir…  a little heavier, but I know Menard’s sells some good boards from which I can cut suitable pieces for the laminations.