Horizontal Stabilizer Final Assembly Started (10/25/09)

3.8 Hours –

I woke up today with the goal of smashing some rivets.  For me, getting to a step where some rivets go in would feel like a huge accomplishment. Plus, I wanted to see how well the pneumatic squeezer worked on some 4- rivets.  Yes, I’m one of those people that loves the little things in life!

My work was broken up into two shifts.  Unfortunately, I had non-airplane related stuff that had to get done too. 

In the morning, I started by cleaning and priming all the HS ribs.  Once the primer was on, I moved over to the HS skins and started to deburr the holes and edges.  This was a time consuming process and I only managed to deburr the holes in one skin before I decided it was time to break for lunch and go get my other stuff done.

The HS ribs are primed and ready for assembly.

More tedium...deburring the HS skin drill holes.

In the afternoon, I returned to my HS skin deburring task.  It probably took me another hour to finish the holes and edges of both skins.

Using a dove-tail deburring tool to break the edges of the skins.

Using a swivel style deburring tool in the tough to reach areas.

After deburring the HS skins, I began dimpling all the holes.  I dimpled as many holes as I could with my pneumatic squeezer and then switched to a c-frame dimpler.

This was the first time I used my c-frame.  Fortunately, I checked it’s alignment before whacking away on it with a hammer.  The bottom plate, which held my male dimple die, was slightly out of alignment.  If I would have used it this way, it likely would have dimpled fine.  However, it would have put a lot of stress on my die, eventually causing the male die to break (ouch!). Fixing the alignment was simple, and it actually took me longer to find the right sized Allen wrench than it did to get everything into alignment.

Once the c-frame was set-up, I slid one of the HS skins in and started to dimple the easy to reach holes.  After a few holes, I realized I either needed another hand or I needed to build some sort of dimpling table.  It was difficult to hold these large skins thanks to the bend they have.  I couldn’t find an easy way to hold the skin on the die, hold the bend open enough to allow space for the hammer, and swing the hammer with enough force to get a good dimple.  This was starting to frustrate me and my goal for the day was to set some rivets, so I sat the HS skins aside and reassembled the HS rear spar for riveting.  Maybe holding the skin sideways will simplify this…skins without bends should be much easier.

I dug out the two HS-603PP rear spar channels and the two HS-609PP rear spar reinforcement bars.  After figuring out the correct orientation (my markings weren’t very helpful), I clecoed them together.  As per the instructions, I taped over the holes that will be used to attach the ribs so that I wouldn’t accidentally rivet them.  I also re-attached the elevator attachment brackets so that I wouldn’t rivet those with the wrong sized rivets.

With everything clamped together and marked, I was ready to smash some AN470A4-6 rivets!  I grabbed a rivet from the bin and tried to place it in the center hole on the bottom of the spar.  It wouldn’t go all the way through both pieces.  After double checking that I had the right rivet size, I took a close look at the rear spar.  Even though the channels and reinforcements were clecoed together on every other hole, the holes were slightly off and not perfectly aligned.  At first, I wondered if I had oriented the reinforcement piece the wrong way, but I quickly determined that was not the case.  Before getting too frustrated, I realized that the clecoes are smaller than the actual holes and could be the source of my problem.  So, I removed all the clecoes from the lower reinforcement piece and placed rivets in the holes instead.  Using this method, everything lined up perfectly.  Relieved that I hadn’t made a major screw-up, I removed every third rivet and put the clecoes back in those holes in order to keep the pieces tightly clamped for riveting.

Finally, it was time to rivet!  Setting up the squeezer on the first rivet was surprisingly simple.  After a couple of progressively shorter squeezes, my rivet gauge said I had the appropriate sized shop head.  With the squeezer set-up, I proceeded down the rivet line, checking every two or three rivets with the rivet gauge to make sure the squeezer was still set-up correctly.  The entire row of rivets took about 15 minutes.  I’m guessing that the same number of rivets would have taken me about an hour with a hand squeezer (if I didn’t get tired and quit half way through).  I left the second row for another day…dinner time!

A perfect shop head according to my rivet gauge.

Riveting using the pneumatic squeezer yields more consistent results.

Finishing Up The Horizontal Stabilizer (10/24/09)

3.7 Hours –

My Dad came over today to help with the airplane for the first time.  Fortunately, there was a lot to do.  Unfortunately, it was all deburring and dimpling, so he got a taste of the tedium involved with building an airplane.

All of the holes in the HS needed to be deburred, as well as the edges of all pieces except the ribs and reinforcements.  I gave my Dad a quick lesson on how to deburr holes and let him at it.  After he finished a small rib, I checked his work.  The holes were deburred and no extra materials were removed, so I let him run with it while I worked on deburring the edges.  Usually, while I’m working, I listen to aviation themed podcasts on my IPod.  It was a nice change to have someone to talk to.

My Dad's job for the day was to deburr the holes in the HS skeleton.

I finished deburring all the edges, except for those on the skins, before deciding to switch tasks and dimple the HS skeleton with my new-to-me pneumatic squeezer.  Using the pneumatic squeezer, I could dimple a rib in less than half the time it took me with my hand squeezer.  I think the squeezer could be my new favorite tool!

Dimpling with the pneumatic squeezer...so simple!

First dimples squeezed using a pneumatic squeezer.

Once my dimpling caught up to my Dad’s deburring, I sat the squeezer aside and started to remove the vinyl coating from the HS skins.  I’m going to only remove strips of vinyl along the rivet lines.  Since I’m planning to leave the majority of the airplane unpainted, I want to protect the skins as much as possible from scratches during construction.

Using a soldering iron and straight edge, I quickly melted lines in the vinyl and then easily peeled off the strips.  Whoever came up with this little trick was one smart dude.

Lines in the protective vinyl are made with a soldering iron.

Left: Once lines are cut with the soldering iron, nice strips can be easily removed. Right: My Dad still deburring away.

As I finished removing the vinyl strips from the two skins, my Dad finished his deburring task and we decided it was time for a lunch break.  My Dad, my girlfriend and I all walked over to Gourmet Burger Grill for burgers, sweet potato fries and onion rings.  If you are in the San Antonio area and you haven’t been there yet, you are seriously missing out!

After lunch, my Dad headed back to Kerrville and I headed back into the garage.  Before leaving the airplane for the day, I wanted to finish dimpling the skeleton and prime the front and rear spars.  With this done, I still need to prime the ribs, as well as deburr, dimple and prime the skins.  However, with the spar pieces all primed, I’m ready to rivet together the rear spar tomorrow.  Yes, I’ll be using my pneumatic squeezer for that too!

Pneumatic Squeezer

I had the noble goal of using only a hand-squeezer on all “squeezable” rivets during my build.  However, after building the tool box practice project and setting a few 4- rivets on the empennage kit, I began contemplating the value of a pneumatic squeezers.

Don’t get me wrong, using a hand-squeezer for the entire project is completely feasible.  However, 4- rivets are a pain in the ASS!  I really have to bear down on them and, after setting a dozen or so, my hands become sore and my forearms tired.  With more time, I’m sure setting 4- rivets with a hand squeezer will become easier (and I will develop arms like Popeye!), but I decided it was time to start researching pneumatic squeezers and buy one when I found a good deal.

New pneumatic squeezers start at around $550.  However, this price generally does not include a yoke.  At a minimum, I will need two yokes to get full use/value of the squeezer.  A 3” and a longeron yoke would be a start, and each of these cost $130ish.

My search almost ended when I found a rebuilt squeezer at Avery Tools for $449.  This squeezer included a 3” yoke and an adjustable set.  However, just as I was about to place an order with Avery, I hopped onto the forums at vansairforce.net and saw a for sale posting for a used pneumatic squeezer.  For $495, it included a 3” yoke, a longeron yoke, quick change yoke pins, a fixed set and an adjustable set.

One thing I have learned is that the RV community is a bunch of trustworthy people, so, site unseen, I made the deal.  When I returned from a week of vacation in Arizona, the squeezer was waiting for me.

I’ve only played with the squeezer a little bit and I can already tell that it is going to drastically speed-up the process of setting rivets.  I can’t wait to use it on the real deal.

Pneumatic squeezer with 3" and longeron yokes.

More HS Work (10/18/09)

2.3 Hours –

Back to building after a week of vacation in Arizona with my girlfriend and her parents.  After a week away from the airplane, I had to spend some time reviewing the drawings in order to remind myself of where I was in the assembly of the left horizontal stabilizer.

Sorry, no pictures today.

First, I finished drilling to size all of the left HS skin attachment holes.  After this was done, I had to drill the holes that will be used to attach the innermost ribs to the front spar.  These holes are a bit tricky because they are not pre-punched and they have to go through two ribs, the front spar, and the front spar splice angle.  If your measurements are off for the placement of these holes, the edge distance may be compromised and you have to order new parts and start over. 

To measure for the holes, I cut a piece of cardboard to the same height as the font spar.  I then placed the cardboard inside the HS near the splice angle and marked where the splice angles ended.  The marks on the cardboard worked as a guide to show me where the holes should be drilled.  Once the rib was center punched in the proper locations, I started to drill.  When the drill came through the splice angle, I was relieved to see that the holes were perfect!

With these holes, the left HS was essentially done except for deburring, dimpling, priming and riveting.  I took the skin off,  removed the splice angles, and started everything all over on the right HS.  On the right HS, I got as far as clecoing on the skin before it was time to quite for the day.

Also today, I received a pneumatic squeezer which I purchased from another builder on vansairforce.net.  I’ll post some pictures in another post, but this is going to save me a ton of time and energy!