Thursday, August 29, 2013

10-10, upper skins


I ended up loosing 3 hours of time when I got confused on my schedule and thought I had to go to work on the 27th.  I got dressed, drove an hour only to find that I was a day early, then drove another hour home.  I made good use of the remaining time and finished attaching the upper skins.   The right side is completely riveted in this photo, but I thought that the warty clecos and ratty blue vinyl made an interesting "before" picture of the L side.  

The cradle works very well, and made it very easy to move the work piece around in the shop as I pulled lots and lots of rivets.  I'm fairly sure I will defer attaching the tail feathers because of space issues.  It's going to be at least a year (or two) before this project is ready to fly and the probability of 'hanger rash' is pretty good if I have a big 8' horizontal stab taking up garage space.  I'll make good use of the cradle and may even move it and the tail cone into the living room and keep company with the tail feathers.


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10-09, static system

Installed the static ports without too much difficulty.  The instructions call for a particular pulled rivet that you then remove the remnant mandrel and end up with a hollow hole in the wall.  I used a C-clamp and socket to gently drive out the mandrel on the R side as I have an extreme allergy to using any kind of hammer on my airplane!  The technique didn't work as well on the L because the mandrel stem I was trying to use a driver wouldn't stay centered so I held my breath and drilled it out with my trusty #52 drill bit.  No problem.  The picture is of the 1st port I installed.


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10-08, side skins, aft bulkhead & trim wiring

Pretty straightforward to cleco the side skins and the aft bulkhead to the nascent tail section.  The confusing part is interpreting the instructions because it never explicitly states to rivet the lower skins to the frames.  I later made a call to Van's and confirmed that it's OK to do so, but it threw me off a bit.  (The instructions tell you to mask off the holes in the forward 7" for later use in joining the tailcone to the fuselage, and to "rivet the open holes" of the skins.  Every other place in the instructions, they explicitly state which parts are being riveted together, so I was a bit confused.)

The strings on the left are going to be used to pull the stabilator control cables.  The coiled white cord on the right is the wire bundle to the trim motor.


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And here's the aft view where you can more easily see the string for the stabilator and the trim control cable.   Note also the veritable hornet's nest of clecos on the aft end where the side skins will be riveted to the aft bulkhead.  Lots of strength needed back there!


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Saturday, August 24, 2013

10-07, Lower Skin Installation

Nice day in the garage / shop by myself.  I had a few personal stressors, and working to some classic rock and a compressor chugging in the background did marvels for my mood (not so much for my headache, though.  Some ibuprofen, caffeine and a nap got me ready for work.)

This is the first time my project has seen the light of day.  We are looking at the left side of the bottom of the airplane.  It is currently upside down.  There are a row of clecos holding the 3 frames to the inside of the bottom and lower skins.  There is a large row of clecos on the forward 7 holes of the bottom skins; those will remain clecoed until the entire tail is mated to the fuselage (sometime in the distant future.)

One of the downsides of the cradle / sawhorse arrangement is that the work surface was uncomfortably high, especially holding the heavy pneumatic rivet gun over the midline seam of the two bottom skins.

I also have a complaint about the holes that were predrilled.  Practically every single one of them needed to be #30 final drilled to accept the LP4-3 rivets.  I deburred those that failed the 'finger test', but was not willing to risk damaging the delicate components by disassembling the entire assembly at this point.  I wonder if anyone else has had this issue.  (It's not a fit issue; the rivets would not pass through a single skin's hole.)


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Here is the view looking from the tail (inverted) along the belly, towards the front.

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Technically, this is the view after 10-08 #1, wherein the assembly is rotated to be right side up.  You can see that I have removed the wooden cross pieces that had been over the tops of the uprights of the cradles.  The assembly fits very nicely in the cradles and it's very secure.  I will probably have to put the cross pieces back on and work with the resulting instability (as well as the inconvenience of working up so high) while I install the side skins.  I hope to get back to work on Sunday afternoon, after I sleep off Saturday night.  On the other hand, if Nick is comfortable coming with me, I may go flying in the C-177.

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Wednesday, August 21, 2013

10-06, Bottom Skin Installation

Major Progress!  I love it when there's a big, visible change in the garage.  Here's the initial assembly of the tail cone itself:  the two bottom skins clecoed to the 3 frames.  (Note the clever creation of sawhorses by putting wood across the top of the cradles.)  Nick hadn't had much interest in the project all day, but did come downstairs towards the end.  He's got a great sense of humor and joked about how his picture makes it look like he did all the work, but he knows that he's just taking the credit :-)


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Remember how I said that I wasn't real comfortable about trying to flute the frames?  Well, I'm still not happy with them, but I'm maintaining the trust that it will all work out when we finish up the skins.  When you look at the frames from the edge, they resemble potato chips more than flat disks...

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Not all was well in Camelot.  Here are two perfectly formed cleated rivets.  The Book called out 270AD4-4's, which I know I placed properly, only to find that they had cleated.  My analysis is that the -4 is too long, but that there aren't any 270AD4-3's.  I ground down some -4's to about -3's and they installed very nicely on the other side.  I tried to take a picture of the modified rivets, but failed to note that they had rolled to the wrong orientation to show of their new, svelte appearance.

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I drilled out one of the cleated rivets without any problem and installed a modified rivet.  (These were checked with the rivet gage and met spec.)  The other one (as shown on the right in the photo below) did not drill out cleanly and I was left with an ugly, out of round, nasty looking hole.  Consulting The Book, the remedy called out is to drill with the next size up and use a larger rivet.  I don't have any AN27-5's, but had purchased a spare rivet puller with an assortment of pop rivets, including some 5/32's, for just such an occasion.  One of those was installed as you see here.

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10-05, Stabilator Hinge Washers

Although I didn't take a picture of it, I had a very good fit of the aft bulkhead into the stabilator.  The book calls out for selecting washers that minimize the lateral play, but I didn't have any lateral play, even without any washers.  I eyeballed the gaps and decided on using the 416L (half thickness) washers in all 4 locations.  The two photos show a close up of the hinge assemblies with a 1/4" aluminum rod playing the role of the AN4 bolts.  The washers themselves are barely visible in the photos as we are seeing them edge on.  They have been glued in place with superglue, as called out by The Book.  I had a devil of a time just trying to see the gaps with the aft fire wall in place, and that was with the advantage of not having a completed tail cone in the way.  Even with the nifty washer holding tools (courtesy of VAF), I expect that the installation of the stabilator on the tail cone will be a major chore.

I also took the opportunity to remove the hinge stops in order to get an extension onto the hinge bolts and verify they were at the proper (24 in-lb) torque.  I have not had much luck getting a low range dial type torque wrench to measure the torque of the nylon lock nuts, so I made an estimate of 6 in-lbs and torqued to a total of 30.


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10-02 (#1-#2) Tail Skins Prep

The first two steps of this page were skipped earlier due to no need to move pieces around and just put them back again. For today's work, all 9 of the tail skins were identified and edges were broken as called out.  

This photo shows all 9 of the tail skins resting in the new cradle.

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I used the tool based on a pair of vice grips with some steel rollers welded on the jaws.  The adjustment of the vice is very sensitive and I ended up making adjustments on the order of an eighth of a rotation in order to get a good feel and to leave a good edge. You can see the broken edge on one of the pieces.  You can barely see a crease that goes along the rivet hole line.  When viewed along the edge, the edge itself is just bent a few degrees.  We'll see how well that works in a few pages.

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Empennage Cradle

Took a bit of a detour to make a cradle to hold the empennage.  Plans came from a gentleman on VAF.  The most expensive part was the 3/4" sheet of plywood, of which I only needed half but had to purchase a full sheet.  The piece went together without much drama, although I did get distracted by some neighbor hood kids (6 & 8 yo) who asked enough questions that I cut the wrong piece and needed to get yet another 2x3 (not making 2x4's anymore I guess.)

I naively thought that the uprights would replace the need for the sawhorses called out on page 10-06, but the 45° brace gets in the way.  No problem.  You'll see this in another posting with some 2x3 screwed in across the tops of the cradles, thus making elevated sawhorses for that step.  


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Saturday, August 17, 2013

10-04, aft bulkhead

I completed the aft bulkhead this afternoon without too many problems.  No rivets had to be drilled out for a change!   It's a bit scuffed up, but I'm working on learning how to work the aluminum without scratching it and making an unpretty part.  This is the front side, looking at it upside down.


IMG 2573And here is a sideways view.  Lots & lots of hand squeezed rivets!  It took a few minutes of head scratching to figure out how to get to the 270's right next to the ears, but I finally had the inspiration to put the squeezer head through the counterweight access hole and after that it was a piece of cake.

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Next step is to detour to the making of the cradle in which to build up the tail cone.

Friday, August 16, 2013

working on aft bulkhead

This posting isn't one of the regular "page completed" posts, but I haven't had much time to work on the plane, and this page (10-04) takes a long time.  (It has lots and lots of hand-squeezed rivets.) You can see the previously completed frames hanging on a clamp in the background.  On the table are my tools currently in use when I had to stop and get my afternoon nap before working tonight's shift.    You can see the aft bulkhead being held upright with a table top vice.  The blue painter's tape is holding wood blocks onto the bulkhead so I could clamp it in the vice.  I decided to start with the "easy" rivets, and did all of the pull rivets first.  I did two of the (limited quantity) LP4-4's before I realized that the attach bracket was supposed to be placed first, so I had to drill out two of those.  Hopefully, Van's gave me a few extras, or sometime in the future I'm going to be 2 LP4-4's short.  There was a 270AD rivet that was too far from the edge to get a good seat with the squeezer.  I ended up with a smiley, so I drilled it out and tried again, but I just couldn't get a good seat.  I had read that there is a place in the fuselage where Van's actually calls out using flat dies on a 270 rivet due to spacing and that it is a permissible technique, so that's what I did.  Anyway, it was 2:00 in the afternoon when I had to call it quits and take my nap before work.  I hope to finish up the page on Saturday the 17th.


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Sunday, August 11, 2013

10-03, aft bulkhead parts prep

Pretty routine stuff.  Cut parts apart, trim surplus bits, buff & deburr.  The doubler looks odd since it's asymmetric, and I'm curious about the fact that the brackets (L lower quadrant in the picture) are doubled on one side but not the other.  Oh, well.  I'm sure it will fly...


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10-02 (#3-#10) Frames

Well, after a long week at work, I was finally able to get back to the shop and do something fun!  Although I had planned on getting some lumber to make an empennage cradle, I couldn't resist getting back to the kit.  I elected to skip steps #1 and #2 because they simply call for identifying and doing the 'breaks' on the edges of all of the skins.  My skins are currently scattered in the garage and under the couch in the living room, so getting them out, breaking the edges, then putting them back didn't make any sense.  On page 10-02 I've noted that I have completed steps #3-#10 and created a new signature block for #1 and #2 when I get ready to use the skins.


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Here are the 3 frames.  I did have a bit of trouble deciding how and how much to flute the frames.  Discussion from VAF confirmed that these parts sometime need to be stretched rather than fluted, but that they often don't need anything since they are easily moved into position.  I expect that I may need to do some tweaking at assembly time, but for now, I believe that they are OK for assembly.



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Frame 1210 was mildy challenging to assemble due to the strength required to squeeze the rivets, plus the awkwardness of their location.  I couldn't come up with a good way to clamp the flimsy frame, and I do like to have some nontrivial back pressure on the squeezer against the workpiece to ensure that I don't have a floating head that doesn't make good contact with the workpiece.  I ended up putting the blanket over the frame and weighing it down with the electric drill.  I had to assume a pretty theatrical pose on one knee with my arms on the squeezer giving it everything I had to start compressing the 470AD4-5's.  Glad I was alone and no one was there to take a picture.

Saturday, August 3, 2013

09-10, Horiz Stab complete

Horizontal Stabilizer is complete.  The control horns are bolted on and the counter weight has been assembled and (temporarily) installed for the photo op.

As mentioned previously, I will probably not be back to work for a week or so.  I will also take a detour and do some carpentry instead of metal work.  VAF has some excellent plans for a tailcone dolly that will facilitate both making and storing the tail cone.  I will probably also make the wing dolly.  I haven't selected the final plan for that yet, but I'm thinking of making one that will have a vertical wall in the center and have it do double duty storing the sheet metal before building an the wings after completion.  If those are done and I like what they look like, then I may also build a dolly / storage rack for the rudder, Vert Stab and AST's.


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09-09, trailing edge of HS

Here's a shot of the trailing edge of the HS with the piano hinges and aft skins installed.

Left Side

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Right Side

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09-08, skins on Horiz Stab

It was several days before my work schedule let me get back in the workshop.  I spent Thursday morning doing small tasks on my own until Nick and Nick (pictured below, left and right) were available to help.  We took the L HS skin out of the living room, deburred it and finally inserted the skeleton, clecoed and riveted it up.  It took the 3 of us about 2 hours.  Little Nick got bored and went back inside to play X-box; big Nick was reclaimed by Melena and they went on an afternoon date.

I continued to work by myself and finished up the chapter (see next posts for pictures).

It's going to be a looooong time before I get back out the shop.  I'm working 9 or 10 consecutive days, so I doubt that I'll have time to play until the 10th or 11th of the month.   :(    On the other hand, I only have the tailcone to complete and I'm not expecting the wing kit until ~ mid September.  It would be logical to *not* attach the tail feathers, but if I have nothing else to work on, I know that I'll succumb to temptation and will put them on anyway.  That will then clutter up the shop for a year…  Oh, well.  Cross that bridge when I get to it. 


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