HS Drilling

Much of the metal preparation work on the horizontal stabilizer was done before I primed and assembled the rudder and VS.  This weekend saw the start of jigging and match drilling on the rear spar of the HS.

IMGP4117As usual, all the parts are laid out and checked before any alterations are started.

 

 

 

 

IMGP4124An initial task is riveting a flange bearing between two powder coated pieces to construct the inboard hinge brackets.

 

 

 

 

IMGP4125Looks just right.

 

 

 

 

IMGP4126Match drilling the hinge brackets and the rear spar doubler is the first order of business.

 

Rudder Assembly – Final

Over the week Eric and I rolled the rudder counterweight skins and leading edges, then finished off with primer and pop rivets.

IMGP4088Bending the skins around the counterweight is imprecise at best.

 

 

 

 

IMGP4090Achieving a tight fit of the bent skins against the lead weight, but smooth with the fiberglass rudder cap, will be a challenge.  Here I am fitting the weight in preparation for the first match drills.

 

 

 

IMGP4093The inner skin will be overlapped with the outer skin, so a light application of SEM self-etch primer from a spray can is appropriate. The two #19 holes for the through bolts have been dimpled to match the countersunk holes the lead weight.

 

 

 

IMGP4097The plans call for rolling the top section first, then middle, then bottom.  A 1″ diameter wooden dowel was used to produce a good profile on the top section.

 

 

 

IMGP4100A 1-1/4″ wooden dowel was used on the bottom section for the larger diameter turn.  The forward edge could have been slightly rounder, but okay overall.

 

 

 

 

IMGP4103The same priming technique for the overlapped section was implemented here.

 

 

 

 

IMGP4108This shot of the middle section shows the final edge bend fastened with AD-41-ABS  pop rivets.  The primed part is just behind the forward face.

 

 

 

 

IMGP4107Voila.  A few dings here and there, but no major blemishes. Overall the effort turned into a satisfying and acceptable result.

 

 

 

 

IMGP4110Just for grins I positioned the rudder next to the vertical stabilizer to admire the progress (like thousands of other builders).  Seems a long time coming, but at least real plane parts are starting to appear.  An interesting side effect of this vanity staging was my recognition the VS spar flange almost totally obscures the forward edge of the rudder.  This means my cosmetic concerns about the leading edge will only be visible to a select group of individuals prior to final assembly.

 

IMGP4113With vinyl now removed, this photo shows the trailing edge being nice and straight.  Eric is in the picture for reference how big the rudder really is (sorry to cut off his head).

 

 

 

IMGP4116On to the next assembly…

 

 

 

 

Rudder Assembly – Part 2

The main focus for this weekend was riveting the trailing edges of the rudder.

IMGP4066The plans suggest partially riveting every 10th hole, then flip over to do the other side.  The whole purpose is to keep the edge as straight as possible.  Here the first back rivet is about to be set.

 

 

 

IMGP4069One side has been partially set, rivets for the other side are now inserted.

 

 

 

 

IMGP4073All done.  If you notice the whole edge is fairly straight, thought the skin between rivets seems a bit wavy. I am not sure this was caused by my technique from over-driving the back rivets, or because the AEX extrusion had big gaps between the rivet holes. Either way to outcome was good (only one smiley location on the entire trailing edge).

 

 

IMGP4076The rudder cap is called for in Section 12, but I still have to fix 5-8 rivets on the counterweight spars.  In the meantime I trimmed down the fiberglass cap to fit inside the rib flanges.

 

 

 

IMGP4083Here the cap is dry fitted to the rib flange and aligned with the trailing edge. Next step is drill out with a #40 bit.

 

 

 

 

IMGP4086The rudder cap here is drilled and clecoed into position. That’s it for the time being on the cap. Later in the build I will final drill to #30 size, countersink the fiberglass piece, and dimple the rudder skin in preparation for LP3-3 blind rivet.

Rudder Assembly – Part 1

After a week in LA on a business trip and another week in bed sick, I finally got back to plane activities.  Over the weekend Eric helped me with the initial rudder assembly, the primary focus is to bond and jig the trailing edge.

IMGP4028Getting ready.

 

 

 

 

IMGP4031My first use of the pop rivet gun was attaching a retaining clip to the stiffener brackets. Here on the top stiffener. Notice how low the clearance is between the right skin and the width of the clip.

 

 

 

 

IMGP4035Here on the lowest stiffener.

 

 

 

 

IMGP4039We used Van’s equivalent of ProSeal to bond the AEX trailing edge strip to the skins.  Here we are smoothing the globs with popsicle sticks. The instructions say you have about two hours to work with the material before it gets hard.  We found it extremely tacky right out of the tube – almost the consistency of Play-Do.  BTW – this stuff really stinks (contains sulfide/sulfate components), so good ventilation is a must.

 

 

 

 

IMGP4045The Van’s stuff comes in a tube.  What they don’t tell you is a holder (like a silicone tube gun) makes the end use a whole lot easier.  I improvised with a piece of spare wood and hand power.

 

 

 

IMGP4047The instructions call for peeling back the left skin and pop rivet the stiffeners one by one.  The lower ones were fairly easy.

 

 

 

 

IMGP4048Pop riveting became increasingly more difficult as the spacing between skins got tighter and tighter.

 

 

 

 

IMGP4049See… 

The left stiffener has to be placed above the right, but below the retaining clip.  Then the forward hole on left/right stiffeners gets pop riveted.  After setting all the stiffeners and the trailing edge, you cycle back to pop rivet  the retaining clips.

 

 

 

 

IMGP4055My big old hands are good for some things, but not others.  As the space between skins got smaller, I started using needle-nosed pliers to insert the pop rivets in the forward stiffener holes. This picture shows the gun aligned with a rivet before pulling.

 

 

 

 

IMGP4060All the stiffeners have been placed, now aligning the upper ribs. Notice the over/under configuration of the stiffeners to the clips.

 

 

 

 

IMGP4061The trailing edge is clecoed down to my special angle bracket jig.  Wooden cloths pins and clamps hold the skins between clecoes.  Now a few days wait for the glue to cure is required before further processing.

VS Assembly

Another power weekend with Rich and the vertical stabilizer is assembled! After months of metal preparation, logistics and practice on sacrificial mini-projects, the big day for actually setting rivets in plane parts was upon me.  In the lead up week, my technical counselor (Terry Gardner) came by to evaluate progress and provide final tips.  With a bit of trepidation and rivet gun in hand, it was time to pucker and pull the trigger…

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Thursday evening the VS spar was assembled.  The spar, spar caps, doublers, and rudder hinges were all squeezed. No worries here and the results were good.

 

 

 

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No drill outs or smileys on the final spar assemblies.

 

 

 

 

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Rich and I made extensive use of a Van’s mini-wing project to practice the rivet/bucking techniques needed for most of the work on skins.  Good thing too, because our initial efforts were miserable.  The greatest damage was done when the tungsten bucking bar slid off the rivet, pounding the h*** out of the skin from the inside.  Many adjustments to the air pressure at the rivet gun were also needed to get things into a calmer, but effective range.

 

 

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I took a day off work to take advantage of Rich’s final days on his visit from Texas. This picture shows the parts staged on Friday morning for both vertical stabilizer and the rudder. The plan was squeeze, back rivet, then buck as many parts in that order.  First priority was completing the VS over the weekend, nice to have the rudder done if possible.

 

 

 

IMGP3996

Back riveting the rudder skins.  This was obviously not part of the VS build, but I wanted to save bucking activities until last.

 

 

 

 

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Again no problem.  The back rivet results are all good.

 

 

 

 

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Here is the final assembly of the static wick nut plates.

 

 

 

 

IMGP4000

Staging the VS frame for squeezing.

 

 

 

 

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Notice the flexible conduit running through the forward rib lightning holes.  My custom rib doubler and the lightning hole wire ties for holding the conduit worked like a charm.

 

 

 

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Okay, here is where a serious case of nerves set in!  Our first ‘production’ bucking experience was on the middle nose ribs.  I had to reach a full arm length into the skin cavity to hold the 1.7lb tungsten bucking bar up against an AN426AD3-3.5 rivet.  Other builders have seriously disfigured the skins in this section; this being one of the most difficult assignments on the whole plane build right at the beginning.  At this point I was very anxious and the pucker-factor quite large.

 

 

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This picture is fuzzy, but does show the finished rivets on the middle nose ribs.  I had to go through some contortions, but eventually was able to see the rivet/bar with a flashlight during the bucking operation. Seeing the rivet shank and not being blind made all the difference.  Added to this, Rich did excellent work driving the rivets with a steady hand and consistent manner.  I was quite pleased with the resulting shop heads.

 

 

IMGP4012

Finishing up the lower spar and spar cap squeezes.  The overall assembly process went slower than expected, but we were very deliberable on purpose.

 

 

 

IMGP4026

Final result on the lower part of spar. We used a 1.5″ diameter mushroom rivet set with a rubber apron for the skins.  The rubber apron kept the rivet set from bouncing sideways and cushioned the impact to some degree.

 

 

 

IMGP4025

Final result on the upper part of spar.  We made sure to use rivet tape on every single flush rivet. This small, but important step keeps the head from crushing off all corrosion protection on the rivet set or die, but also prevents the skins from getting scratched.

 

 

 

IMGP4021Saturday evening saw happy campers and great results! In the end we only had to drill out 3 rivets. Interestingly enough all three of these were squeezed. No smileys or dents in the smooth skin surface are also testimony to careful planning and solid execution. Who would have thunk it given my previous concerns about bucking.

I could not have achieved this excellent outcome without Rich’s help.

First Contact

Another power weekend finally saw the first parts riveted together!

IMGP3927On Saturday Rich helped me apply PreKote to the skins with a light scuffing with grey Scotchbrite.  The process is simple – apply, scrub, rinse thoroughly, hang to dry.

 

 

 

 

IMGP3965The treated rudder skins are hanging from the dryer racks in the shed.  The were left overnight to dry with a space heater and a 1000watt floodlight on to combat the near freezing temperatures.  With all the devices running, the shed maintained a comfy 23 degree Celsius.

 

 

 

IMGP3967On Sunday after lunch I got suited up and ready to spray.  Each time the process of preparation gets a bit smoother.

 

 

 

 

IMGP3968Back in the bonus room with my first two parts to rivet in hand.  Because these were not part of the Van’s build plans, I started with my custom-made doubler for the upper VS rib. Note all the primed VS and rudder parts on the drying racks in the background.

 

 

 

IMGP3970First contact! but also brought first mistakes.  The first set of squeezed rivets went so well, I overzealously put a rivet in the lower right drilled hole.  The three in this row are supposed to attach to the forward VS spar.  Okay, so used the rivet removal tool for extraction.

 

 

 

IMGP3972Just to prove I can make more mistakes, here is a closeup of the final rib combination. Close examination shows the forward nut plate rivets are slightly bent inward.  I was using the Main Squeeze tool properly, but with driving bits too short.  This caused the C-yoke to contact the nut body at the end of the squeeze, forcing the small angle on the rivet.  By using taller driving bits on the second nut plate, I got full clearance on the nut body – thus no contact, no angle and a resulting smooth surface.

 

 

IMGP3971Had only the nut plate been slightly bent, I would have drilled out and replaced it.  However, the doubler was also impacted and further rework would probably have done more harm than good.  This is one of those occasions where the outcome is fully functional, but not esthetically perfect in the eyes of the builder.

Overall this was a great learning experience, and hopefully the beginning of a constantly improving build process.

Breaking Bad

This was a power weekend – alodine and priming my first set of plane parts with expert assistance from Rich.

IMGP3864Here we are finishing the air handling system for the shed.

 

 

 

 

 

IMGP3866Getting staged for mixing brightener – dilute phosphoric acid with brand name PPG DX533 (one part to three parts distilled water).

 

 

 

 

 

IMGP3873The actual mixing process occurred in the shed to keep any fumes or spills out of the house.

 

 

 

 

 

IMGP3887Here Rich and I are posing in front of the treated parts, first dunked in the brightener solution and rinsed with water.  The drying racks just hold the pieces before the alodine process, no real need to have them bone dry at this point.

 

 

 

 

 

IMGP3892One of the VS spars goes into the alodine solution in the dunk tank.  The first pieces in the fresh solution for 2 minutes turned very dark, so the immersion time was adjusted to get a more golden color. Everything was hung overnight with a space heater on for complete drying.  This is necessary before the priming steps.

 

 

 

 

 

IMGP3896Suited up and shaking the PPG DF40LF grey-green primer.  I only got a quart, which turned out to be way more than needed for this batch of parts.

 

 

 

 

 

IMGP3900Using a graduated measuring cup marked for 2:1 primer to catalyst.

 

 

 

 

 

IMGP3908Ready, aim, fire.

 

 

 

 

 

IMGP3914Rich took this picture through the shed window showing primer actually being applied to some parts.

 

 

 

 

 

IMGP3916Why the grin?

VS Metal Prep & Logisitics

Spent time this week preparing for the big two week building push expected during Rich’s visit in early March.  I fabricated a pair of drying racks from 1×1″ pine boards using medium eyelets to hold hooks made from 14/3 electrical wire. This combination was cheap and seems to work fine.  Also scuffed the non-skin components of the VS and rudder.

IMGP3853Here all the parts are staged prior to scuffing.

 

 

 

 

IMGP3854Used the spare bathroom and a doggie shower attachment to scuff with maroon Scotchbrite and green Dawn dish washing soap.  This action also took off the major grease and grime from earlier processing steps.  This is a porcelain tub, so a rubber bath mat cushions the parts in this picture.

 

 

 

IMGP3856All the parts are scuffed, cleaned and are hanging on the new drying racks.

 

 

 

 

IMGP3860I manufactured a fake window box for the dual fan setup in a few hours with cheap 2×6 pine boards. The fan is supposed to move 1420 cfm, the whole shed is 800 cubic feet.  If all goes as planned, a complete air turnover will happen twice a minute – not bad for a home paint booth.

VS Upper Rib Doubler

I spent some time this week going back to major parts of the vertical stabilizer and rudder to smooth the edges much better than my original efforts. Last week my technical advisor had shown me how edges should look. In retrospect a rather poor job had been done on final rounding my parts with the Scotchbrite wheel.  Fortunately, none of these parts have been riveted together.  The results now look much better.

The other activity this week was fabricating a rib doubler for the uppermost rib on the vertical stabilizer.  I want to use 3/4″ plastic conduit obtained from Van’s to feed wire for either a VOR antenna, an anti-collision LED beacon, or both to the top of VS.  The conduit can be held in-place with the appropriate sized hole drilled with a unibit.  However this would weaken the spar web, so a doubler is needed.  In addition, I wanted to use the #10 screw nut plate trick, ala the bonding straps, to allow for later installation of any electrical equipment.

IMGP3837A scrap piece of sheet aluminum is measured out for the rib doubler.  This picture shows the position of the nut plates, the unibit to be used for the 3/4″ hole and a practice piece of plastic conduit.

 

 

 

IMGP3842Here is the doubler rough cut for  insertion into the upper VS rib.

 

 

 

 

IMGP3849On the left is the fabricated doubler with all the holes drilled and deburred.  I countersank the nut plate lobe holes for flush riveting with an ‘oops’ rivet.  I wanted this to be flush for flexibility of later installations.

On the right is a practice piece with the plastic conduit inserted into the 3/4″ hole.  As can be see here, the conduit has alternating bands of 3/4″ and 7/8″ diameter sections.  This will allow the conduit to be threaded through the unibit hole and self-attach to the rib doubler. Nice and neat.

The lower VS ribs do not need this treatment, as special Panduit wire ties will be attached to the already present lightning holes.

HS Preparation – cont.

This week I finished the deburr and Scotchbrite treatment of most horizontal stabilizer parts. In addition, I ordered a 2hp, 7.2 cfm Sears Professional air compressor, a Bosch JS470E hand jig saw, and the final set of parts/accessories for priming.

IMGP3796With earlier work on smoothing edges, I had tried various combinations of Dremel sanding bits, 400 grit Emory cloth, and Vixen files.  The best results so far are obtained using a fine bastard file on the really rough sections, followed with a very fine needle file, then a deburr tool to round over the sharp corners and finally smoothing on a 6″ Scotchbrite wheel mounted in the drill press. It takes quite some time per piece, but the results are very good.

 

 

IMGP3801This photo shows me using a medium file to shape the end of a HS spar cap rough trimmed with a band saw.

 

 

 

 

IMGP3798The deburr tool run 2-3 times over the edge of the spar cap will take off the sharpest corners (which are the result of Van’s manufacturing process of high-pressure water jet cutting, then bending in special jigs at the factory). Here the spar cap is clamped to the angle iron jig I originally made to hold the rudder trailing edge section.  This jig has been handy for a number of other operations as well.

 

 

 

IMGP3806My EAA technical counselor, Terry Gardner, was kind enough to spend an evening in his shop with me producing the HS attachment brackets from raw angle aluminum stock.  An earlier post showed my rough measurements, Terry was able with his Bridgeport milling machine to achieve 0.0025 or better tolerances on all the holes.  On the left is the final milled piece coated with the blue dye used for accurate scribing, the right bracket has been cleaned and polished.  These are results I could never have achieved by myself with hand tools. Thanks Terry!