Lessons Learned
or
Things I would do differently
The purpose of this page is to pass in specific things I've figured out about building this particular aircraft.  Some of these ideas may not
translate to other aircraft, but they made a big difference to me, and if I would have know these things before I started, they would have saved
me huge amounts of grief and time.  I pass them on here for anyone who may find any of them helpful.  Please remember that I am not an
A&P mechanic and have never built an airplane before, so for some of you experienced guys, some of these items may seem pretty obvious.  
The point is that I didn't know them beforehand and its very likely that some other builders out there may not know this stuff either!

I'll be adding more info and photos later.  This is just a start.
Epoxy
  • Use the manufacturers suggested methods. I can't say enough good things about West System epoxy. When I started having
    problems with glue joints cracking (not their fault - see my log) I called them up and they jumped all over the problem.  They wanted
    samples of the batches of glue from each job and samples of fresh glue.  They wanted pictures and more samples.  They had a meeting
    every Friday with several of their engineers and discussed my problem.  They eventually figured out that if I controlled my humidity issues
    and used their product the way they recommended, I wouldn't have any more problems.  They sent me all sorts of guides and manuals on
    best practices and I even get a magazine once in a while showing lots of pretty elaborate projects that other people are creating using their
    products.  The big thing that I discovered after reading their product guides is to use a thickener and create very large fillets on the glue
    joints.  This creates a much larger bonding area and eliminates the tight angles than can focus the various stresses into a very small area.
  • Avoid Bake-offs with ice. (more to come)
  • 2nd coats of epoxy. (more to come) Timing and pigment.
Tools
  • Variable size hole cutter. I started trying to cut the lightening holes (there are a LOT of them) with hole saws or with a jig saw and then
    sanding to final shape. I mentioned this to some old guys at an EAA meeting and they told me about this wonderful tool that lets you cut
    holes to any size you want.  You just adjust the arm to where you want it and you get perfect holes every time.  Another little tidbit is that
    the plugs that come out when you cut the holes make great clamping pads.
  • 4" to 6" angle grinder with a sanding disc.  This was recommended to me by one of the other Tally-Ho builders.  You can remove
    very large amounts of material in a very short time.  It also is surprisingly easy to very precise with it, allowing you to get very close to final
    shape very quickly, leaving only a little finish sanding to do.  The drawback is that it creates large amounts of very fine sawdust.  But its
    often worth the trade off.  When I use this tool I will often recruit a helper to stand right next to me with a large shop vac and try to capture
    as much of the dust as possible as I create it.
  • Thimble Sander.  This is the ultimate tool for shaping those inside corners on the bulkheads, ribs, etc.  Its almost like this tool was
    designed specifically for making bulkheads!
  • Laser Level (more to come)
  • Detail Sander (more to come)
Wood
  • Use the good stuff.  The guy at my local hardwood shop was out of aircraft grade plywood and suggested some marine grade stuff.  I
    talked with Terry and he assured me that marine grade was fine for the fuselage bulkheads as they aren't actually stress bearing, they only
    create the shape for the skin and the skin caries the loads.  So I went ahead and used the marine grade stuff for most of the bulkheads.  
    What a nightmare!  Its called Ocume, and even Wicks and Aircraft Spruce sell it.  Its a dark wood from Africa that is manufactured in
    France. To me it feels much heavier and it splinters and splits like crazy.  Even with backing clamped in place it splintered when drilled or
    hole sawed. I spent large amounts of time patching up the splintered edges with epoxy.  The aircraft grade birch I got that came from
    Finland hardly ever splintered and had a much nicer finish, seemed lighter to me, and much stronger.  There's no doubt that the dark
    marine grade stuff is very pretty when finished, but I'm painting everything anyway.  Its also cheaper, but not worth the trade-off at all.  
    You'll never catch me using that stuff again!
  • Wood shrinks when the humidity drops - A LOT!!  If you read my log you'll see the extreme difficulties I had with humidity causing
    the wood to shrink as much as 5%.  This probably won't apply to most builders, but I live where it gets really cold (-40 to -60F) for several
    moths out of the year. This completely removes the humidity from the air and I've been told that in some situations its even referred to as
    negative humidity as it draws the moisture out of everything.  This is especially true of wood.  There have been several occasions where
    visiting musicians have their instruments warp or crack within a day or two of arriving in town. I've discovered that the owners of high end
    wooden aerobatic aircraft keep them stored in temperature and humidity controlled hangers.  The only way to deal with too little, or even
    too much humidity is to run humidifiers (or dehumidifiers) and pay great attention to sealing the wood.  Terry was very adamant about
    this, but he was concerned about too much moisture where he was from.  I can tell you that I need to be sure I get everything sealed to
    keep the moisture in or the aircraft structure will actually tear itself apart.
  • Steam Works Wonders! (more to come)
The "Tally-Ho" Plans
  • Overly precise dimension call outs. In several situations Terry handed the drawing of the plans off to a 3rd party.  It looks like the guy
    putting the call outs for the dimensions often "pulled the measurement" directly from the drawing using standard Autocad tools.  This
    created very specific measurements that, if taken at face value, will drive you nuts if you try to comply with them.  You will often see
    measurements, especially for larger diameter holes or radiuses in 16ths, or even 32nds that don't even need to be within an 8th to be fine.  
    I spent an enormous amount of time on the jig fences trying to get the specified holes exactly positioned and cut to the right size.  I bought
    several sets of drill indexes and expensive hole saw kits to get some of the more unusual sizes that were called for in the plans.  In
    retrospect, the only reason for the holes in the fences are to allow you to install some of the stringers and longerons while the jig is still in
    place.  Those holes could be ANY size as long as they are large enough and don't weaken the structure of the bridge piece.  Even if you get
    them wrong its an easy matter to grind them out a little bigger if you need to when the time comes. There are other places where this
    occurs.  So if the measurement seems overly precise, back off and look at the context and decide if it really needs to be that way.
  • Printing/Scaling errors. Check the full size templates!  On more than one occasion I had cut out and finished shaping and sanding an
    expensive piece of wood only to find it was the wrong size.  At first I blamed the plans and thought bad things about Terry and his
    draftsman (I even called up and confronted Terry about it once) only to find out it was my fault!  The plans come on a CD as .PDF files that
    you either take to a copy store or plot out yourself if you have access to a standard plotter.  However, if you plot them out yourself you will
    find out that there are lots of settings available when it come to orienting the drawings on the roll paper, paper size, etc.  It turns out that
    on more than one occasion I somehow ended up with a type of "auto scaling" enabled when I printed a particular sheet. This doesn't make
    too much difference on most of the plan sheets, but its critical on the full size template sheets.  So before you use a template sheet as a
    template - BE SURE to measure one of the drawings for accuracy.  If the plan says its a full size template and the call out says its 4 inches,
    measure it and make sure it actually is 4 inches.
  • Many metal piece templates don't have bend allowance included. (more to come)
  • Elevator pulley bushings vs sealed bearings (more to come)
  • Elevator hinges (more to come)
  • Elevator and Stab hard points (more to come)