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Score!

I haven’t been doing much on the biplane recently, but I did manage to score an altimeter for it.  I’ve been watching the for sale ads on line for decent deals.  Someone offered an altimeter that worked, but failed an IFR certification due to out of tolerance leakage at 15,000′.  Well…  if I ever do finish the bipe and fly it, it certainly won’t be at anything over 10K, let alone 15K.  So for fifty bucks it was a no-brainer.  It’s a pretty nice altimeter, not one of the super cheap imported junkers that’s being sold now.  It’s really more altimeter than I need… 

My “new” used Shinko Electric altimeter

So…  I have an altimeter, and a quad oil temp / oil pressure / CHT / EGT gauge for monitoring the engine.  I will still need an airspeed indicator.  Most that I see for sale have speed ranges not appropriate for the Celebrity — I really don’t need or want a 200 knot ASI.  Then I’ll need a compass, of course; a slip/skid ball; a tachometer.  Whether I need a fuel gauge or not depends on what I decide to do for fuel tanks.  I’m thinking no electrical fuel gauges, all float or sight type.

I could just ditch all of it and go with a single instrument from Dynon or Garmin, but I just think such a thing would look out of place in a classic biplane.  I’m not sure what I’ll do for the front cockpit, though.  It would be nice to at least have airspeed and altitude there for passengers, but I’m not sure I’ll be able to score a deal like this again.  There’s always UMA…

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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.

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Plugging along on aileron ribs

Five down, eleven to go.  Cutting the geodetic braces individually is really not as much of a chore as I thought it would be.  I am finding that I’m going through the 6′ lengths of stock quickly, though — I figure I have enough shaved down for the next 3 ribs, maybe 4, then I’ll have to fire up the drum sander again and make some more.  Not that it’s stupidly tedious work or anything, mind you.

In hindsight, it would have been a whole lot less work and actually less expensive to have bought 3/8″ thick spruce spar stock and just ripped it down to 3/32 strips, losing half the board to saw kerf.  I am at a loss to explain why that little bit of math didn’t make itself obvious.  Of course, I thought at the time that shaving 1/32″ off those strips would be quick and easy.  Not so much.  So…  if you’re building a Celebrity from plans, you’d be better off doing that.

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What next?

It’s a little early for this debate, but given the long lead times for ordering wood…  not too early.  I could possibly be done building the wing ribs in a month or two, if I get on it with a purpose.  If I’m going to need a bunch of spruce, I probably need to get the order in now.  So the question becomes — what next?

  • I could build the wings.  It looks like the wood for the spars will cost me around $8-900, plus substantial shipping.  I’d also need to extend my workbench by at least 4 feet, so that’s another project in itself.  But I’d have wings, man, which would look bitchin’ cool hanging in the garage or hangar.
  • I could start on the fuselage.  It’s a big piece that would be a huge leap forward.  I haven’t calculated the wood cost yet, but it’s a significant amount of birch ply and spruce.  Again, I’d have to build another workbench to extend what I have by 8 feet or so (and rearrange the garage).
  • I could start on the tail feathers.  I could do all the work on my existing workbench.  After looking at the parts list, most of the wood specified is pine; I’d need some aircraft ply as well.  The elevator & stab. spars are specified as spruce, but I could source suitable quality Douglas fir locally and substitute that.  I’ve seen boards at Menard’s with growth rings and grain slope that meet specs, with enough defect-free wood to be usable.  That means all I would need to ship from Aircraft Spruce or Wick’s would be a couple sheets of plywood.  Plus, building the tail would give me some valuable experience with large/long glue-ups that I’ll need to do for the wing spars, and if I screw it up it’s relatively cheap pine instead of very expensive spruce.

So…  tail feathers it is.  Now I just need to consult the plans and see what size sheets of plywood I will need to order.

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First aileron rib

Full rib top, aileron rib bottom.

Yesterday I glued up the last full rib (#26) and the first aileron rib.  I’m going to call this a milestone.  🙂  I now have 15 more aileron ribs to go, then 34 false ribs.  I suppose I should pull out the plans sheet for the spars and see exactly what I need to order for them.  I have the BOM, but it doesn’t really tell me what I need to know without looking at the plans too.

I had to look at the plans a few times.  It looked like the plan sheet was calling out just one geodetic brace to omit for the aileron ribs, but the locations to mark for eventual cutting didn’t make sense.  I finally realized that the text read, “Omit this X-brace for aileron ribs”…  as in, BOTH braces, not just the one.  Great!  That’s two less pieces to cut and glue.

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Back to working in pairs

I finally went out and got the second rib jig from the garage and brought it down to the basement.  Ribs 24 & 25 are now curing, they will be ready to pull tomorrow evening.  My new routine:

  • Put the first jig on the bench.  Cut all the pieces fro one rib and set the geodetic pieces above and below the rib caps, ready to glue.
  • Stack the second jig on top of the first, cut all the pieces for it.
  • Mix up enough glue for both ribs (14cc seems about right)
  • Glue up the rib in the top jig and set it aside.
  • Glue up the rib in the bottom jig.

Double the completion rate.  I’m out of pre-cut geodetic pieces, so now I”m marking and cutting them individually with a razor saw.  It doesn’t take much longer, really, and each one is cut exactly to fit.

I’m almost out of pre-curved top capstrips.  The comments on the plans say you can bend the spruce dry and glue the ribs.  I don’t like the idea of having that much tension on the wood.  The nice thing about working indoors, though, is that I can keep hot water hot longer.  When I run out of pre-bent pieces, I’ll try the hot water bend method again.  In the garage the water cooled off far too quickly.  In the basement, I can get REALLY hot water in a capped length of PVC, and keep it hot long enough to soften the capstrip.  System 3 says T-88 works fine on damp wood…  I’ll try that and see how it goes.

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Got rib #22 done…

I finally took a minute to go out and count the ribs hanging in teh garage today.  Combined with the ones in the basement, I have 22 of the 26 required full ribs.  Four more and I can start on the 16 aileron ribs — they are identical to the full ribs, but missing one geodetic brace.  After that will come 34 false ribs.  I’m considering (maybe) using 1/16″, 2mm or 3/32″ birch plywood for those, just to speed up the process.  Haven’t decided yet, and probably won’t do it because of weight.  We’ll see once I get to that point.

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Six down.

Progress has been slow, much slower than I planned, but really — building ribs is a pretty low priority.  I have knocked out half a dozen in the basement, to add to the I-forget-how-many in the garage.  I’ll need to count them up soon, but I know I’m not at 26 yet, which is the count of full ribs I will need.

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Back at it – more ribs

Got the basement workbench cleared off enough to move rib production indoors.  So far I’m only using one jig, but I’ve knocked out two ribs now.  I need to get the second jig set up.  One rib per day isn’t going to cut it.  Sure is nice working in the basement instead of the garage though.

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It’s damn cold outside!

I’ve been wanting to get back to building ribs.  The garage bench has been piled too deep to get anything done, and now it’s been below zero for over a week solid.  Insulation or no, it’s damned cold out in the garage.  Too cold for epoxy to cure, and too cold to work.

So…  there’s a perfectly good work bench down in the basement.  8′ long and rock solid, built by Dad back in the 1960s.  It’s been pretty much completely covered up for the past several years with a collection of parts, partially-disassembled or -assembled prototype projects and assorted debris from the side business I was running, plus a CNC router that took up about 3′ of it.  I have cleared most of it off (much of it into a trash can).  The CNC machine is shelved for now; I’ll maybe resurrect it when needed at a later date.  It will probably come in handy for cutting the instrument panel and/or nose ribs.

The next issue is containers for the geodetic rib braces.  There are 24 braces used in each rib, all of which are of course slightly different.  Just enough so that none are interchangeable.  I was using paper cups to hold them in the garage, but it’s a completely unsatisfactory solution.  In the basement I think I’m going to try stapling taller plastic cups along the back edge of the bench and see how that works.

I’m not moving power tools down there from the garage, so new geodetics will be cut with a razor saw.  We’ll see how that works out…  it’s one of those jobs I wish I could set up a machine or fixture to do.  It’s 24 different lengths with over 40 different angle cuts, so I’m not sure how I’d make that work.  Even cutting them out in batches on the band saw meant fine-tuning each one with a sanding block before assembly.  It’s fiddly work and tedious as hell.  Classic gusseted ribs would be a whole lot faster and easier to build.  If I were starting this over I’d probably just depart from the plans and build them all that way; I’d probably have them all done by now.