Archive for category Horizontal Stabilizer
Starting To Rivet the Left Horizontal Stabilizer Skin (10/31/09)
Posted by Ethan Jacoby in Construction, Empennage, Horizontal Stabilizer, Tools on October 31, 2009
2.5 Hours -
My new torque wrench arrived in the mail today, so the first thing I did was torque the bolts holding the HS-411PP center bearing to the rear spar. The plans recommend 20-25 inch pounds of torque for these bolts, so I set them to 25 and marked them with some “torque seal.” Ok, my “torque seal” is actually some nail polish that my girlfriend bought for me earlier in the day and I went a little overboard with it. Keep in mind, this was my first endeavor into nail polish use!
My new beam style torque wrench from Park Tools.
"Torque seal" (aka nail polish) on the center bearing bolts.
My girlfriend "torque sealed" her toes.
Next, I continued my work on the left HS by riveting the bottom of HS-707 to the skin. You can use solid rivets or blind rivets here. I couldn’t figure out a good way to buck rivets in this confined space, so I decided to just go with blind rivets. I’ll try to avoid using any blind rivets on the tops, but on the bottoms, where no one will see them, I decided the blind rivets would be a better choice than trying to buck and doing a horrible job.
I chose to blind rivet the bottom side of the HS-707 rib.
Three blind rivets were also used to connect HS-707 and HS-708 to the front spar. These were also a little tricky to place thanks to the confined quarters created by the skin.
Blind rivets attaching the left HS-702 to HS-707 and HS-708.
Assembly of the left HS continued by riveting the outboard most rib, HS-706, to the front spar. Using two universal head rivets.
Finally, I started to rivet the left skin to the front spar. The small flush rivets used to attached the skin are relatively easy to set, but getting the bucking bar into place was, once again, a challenge. I spent a good thirty minutes trying to develop a plan of attack. Eventually, I started to buck rivets and set all the rivets attaching the skin to the bottom of the HS-702 front spar before calling it a day.
Bucking rivets is a slow process, but I'm happy with the results so far.
Tomorrow, my Dad is coming over to lend a hand again, and I think we will be able to finish up the HS!
Left Horizontal Stabilizer Assembly Started (10/29/09)
Posted by Ethan Jacoby in Construction, Empennage, Horizontal Stabilizer on October 29, 2009
1.0 Hours -
Initially, i went into the garage only to clean up a bit and get things ready for tackling the final HS assembly in another day or two. Of course, once I was in the garage, I had a one track mind. My fifteen minute clean-up turned into a 1 hour work session which only ended thanks to a minor injury. More on that later.
The first step in assembling the left HS is to cleco the HS-707 rib to the inside top of the skin. It is then riveted to the top. However, it was really tricky to get the bucking bar into place, while holding the rivet gun. This is another task that would be easier with another hand, but a little ingenuity and I got the job done. Granted, this wasn’t my best effort at riveting, but it will do. The shop heads are perfect. The factory heads weren’t bad, but I did ding the skin around one rivet.
The shop heads inside the skin look great. I'm not as happy with the outside.
I'm not too happy with these, but they were incredibly hard to get to.
After the top of HS-707 was riveted to the skin, I clamped the bottom of HS-707 to the skin and then clamped HS-706 and HS-708 in. With even less space to reach into the skin than when the top of HS-707 was riveted, I couldn’t figure out how to rivet this piece. The plans say that you can use pop rivets instead of solid rivets on the bottom. I knew that I would have to use pop rivets on at least the two forward most holes, so i decided to start there and make up my mind on the rest of the holes later. As I started to pull the first pop rivet with my pop rivet tool, I wasn’t paying attention to where my hands were. I squeezed the pop rivet tool one final time and, when the shank of the rivet snapped, the handles of the pop rivet tool smashed together with my left middle finger in between them. The edge of the handle went through my fingernail.
I was attacked by a pop rivet tool!
While it hurt like crazy and I’ll probably lose my fingernail, I’m fairly sure that I prevented any blood from getting on the horizontal stabilizer. Now, my blood and sweat has gone into the project, a few tears and the plane should be done!
Horizontal Stabilizer Skins Dimpled and Primed (10/28/09)
Posted by Ethan Jacoby in Construction, Empennage, Horizontal Stabilizer on October 28, 2009
1.3 Hours -
Time to tackle the remaining dimples that needed to be made on the horizontal stabilizer skins. I tried to do this with the male dimple die on the bottom of the c-frame (the normal setup), but it just wasn’t working for me without a third hand. So, I took the spring off the c-frame and switched the male to the top. Now, with the skin bending down, there was less in my way. i could line the skin up, drop the male die down into the hole (the spring was removed from the c-frame to make sure I didn’t make any extra holes in the skin), give it a whack with the hammer and, voilà, a perfect dimple.
400 dimples or so later and I was ready to prime the inside of the skins. I’m only priming the mating surfaces, but I wasn’t going to waste time masking the inside of the skins to get perfect looking lines of primer (no one is ever going to see this one the HS is riveted). I simply roughed up the surface around the holes using a Scotch-Brite pad, cleaned the surface with MEK, and sprayed the roughed up areas with primer. Quick, simple, effective!
In order to build an airplane, I’ve realized that you have to overcome your fear of straying from the instructions. You also have to overcome your fear of screwing up. The instructions are more like guidelines. They will tell you a good order to proceed in, but they don’t tell you how to do every little thing. Van’s lets you figure that out for yourself through trial and error. After all, as amateur builders, the Federal Aviation Regulations (FARs) tell us that we are allowed to build for the purposes of recreation and education only. Thirty-some hours into the empennage, I’ve learned quite a bit. However, I also realize that I have much more to learn.
MEK is nasty smelling stuff, but it cleans everything off very quickly. The respirator is more for the smell than anything else.
Not the cleanest lines, but no one will ever see this once it is riveted closed.
Horizontal Stabilizer Front Spar Finished (10/27/09)
Posted by Ethan Jacoby in Construction, Empennage, Horizontal Stabilizer on October 27, 2009
2.0 Hours -
So far, working on the empennage has been in no way frustrating. Tonight, was a different story. Everything started off fine as I assembled the HS front spar. This simply involved riveting the HS-710 and 714 splice angles to the HS-702 front spars. The most difficult part was to make sure I used the correct rivets in the correct holes…simple!
With my confidence up, I decided to tackle attaching the inboard ribs (HS-404 and HS-405) to the front spar. While this sounds simple and takes a grand total of 8 rivets to accomplish, it is complicated by the large amount of flanges that get in the way. Van’s says you can bend the ribs slightly for better access to the rivets. I don’t know what their definition of slightly is, but I bent them a bit out of the way and still couldn’t get to the rivets with my squeezer.
HS front spar inboard rib attachemtn.
No squeezer access, not a problem…I’ll buck them. Well, I still couldn’t get a good angle with my gun and bucking bar. I managed to bend the first rivet over after only a couple of hits from the gun. I drilled the rivet out and tried again with the same result. Once again, I drilled the rivet out and then took a step back to re-think things. Finally, I decided to bend the ribs outward even more. Eureka! With the rib flanges out of the way, I could fit my squeezer in and squeeze all 8 rivets.
HS front spar and inboard ribs assembled.
With the ribs attached, my next step is to start riveting on the skins. However, I still need to finish dimpling the skins and I decided that 8:30pm was too late to be banging on the c-frame with a hammer. I’m trying my best not to piss off my neighbors too much!
On top of needing to dimple the skins, I could feel my frustration level had peaked and knew that it would be best to quit while I was ahead. To lower my stress, I did a quick clean up of the airplane factory. After putting all my tools away, I attached my blow gun to my air hose and proceeded to “clean” my workbenches and garage floor by blowing all the crap off of them at 90 PSI. What can I say, the blow gun is great stress relief!
Horizontal Stabilizer Rear Spar Finished (10/26/09)
Posted by Ethan Jacoby in Construction, Empennage, Horizontal Stabilizer on October 26, 2009
1.2 Hours -
This evening, I was able to finish up the HS rear spar. I finished riveting the HS-609PP bars to the HS-603PP channels and then riveted on the 8 hinge brackets. Finally, I found all the hardware needed to bolt the HS-411PP center bearing assembly on to the spar, but I had to stop there because I don’t yet have a torque wrench.
I spent the next thirty minutes searching the internet for a beam style torque wrench that measures in inch-pounds. I found a few prospects, but I can reach these bolts even after the rear spar is permanently attached to the HS, so I’m not in a rush to purchase. With any luck, I’ll find one I can borrow.
Look Ma, no clecoes! For reference, I'm 6'2" and the spar towers over me.
Horizontal Stabilizer Final Assembly Started (10/25/09)
Posted by Ethan Jacoby in Construction, Empennage, Horizontal Stabilizer on October 26, 2009
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)
Posted by Ethan Jacoby in Construction, Empennage, Horizontal Stabilizer on October 24, 2009
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!
Prepping the Horizontal Stabilizer For Assembly (10/23/09)
Posted by Ethan Jacoby in Construction, Empennage, Horizontal Stabilizer on October 23, 2009
1.0 Hours –
I decided to get in a little airplane work right after my real work…straight to the garage once I got home. First, I wanted to see how my primer test did overnight. The NAPA 7220 rattle can primer turned out great! I couldn’t scratch it off with my fingernail and had to work to scratch it off with a drill bit.
Happy with my primer, I deburred, cleaned, and primed the HS-609PP rear spars reinforcement bars and started to deburr some of the left HS pieces. Tomorrow, my Dad is coming over to help and I hope to have all the HS rear spar assembled and the remainder of the HS pieces ready to rivet by the time he leaves.
The Horizontal Stabilizer Is Ready To Be Prepped and Primed (10/22/09)
Posted by Ethan Jacoby in Construction, Empennage, Horizontal Stabilizer on October 22, 2009
1.6 Hours -
I’ve spent 21.7 hours on the horizontal stabilizer so far. Tonight, I almost feel like I’m back to square one. At least that’s what the pile of parts on my work bench makes it look like. By the end of the night, I had to completely disassemble the entire horizontal stabilizer.
Back to square one...a pile of parts on the workbench!
In all honestly, I’m happy with my progress so far. I’m now done with what I’m calling the preparation phase of the horizontal stabilizer. All of the parts have been match drilled, and all that is left is to deburr, dimple, prime and rivet. OK, all of that will probably take just as long as the preparation phase!
My work tonight consisted of completing the match drilling of the right HS skin to the frame. Once that was done, I removed the skin (taking out all of those clecoes is a real pain), and drilled the outboard holes of HS-710 and HS-714.
The right horizontal stabilizer completely match-drilled and ready for disassembly.
The last six holes to drill in the horizontal stabilizer (for now).
I’ve elected to go with manual trim. At some point in the construction, you have to drill a 5/8 inch hole in the left HS front spar to accommodate the trim cable. Some people wait to drill this until the HS is on the fuselage, but I decided to drill it now, before priming. To do this, I measured the location according to the plans, marked it with a center punch, drilled a #30 pilot hole, enlarged the hole to 1/2 inch with a uni-bit, and then expanded the hole to 5/8 with a tapered grinder mounted in my drill. I’m happy with the results.
A 5/8 inch hole drilled in the left, front HS-spar will be used later on to route the manual trim cable.
Finally, I decided to take my first shot at priming by testing my system on two small parts. I’m going to spend as little time as possible on priming. I don’t want to start a priming war, but I feel that etching, alodining, and then priming is way too much when the majority of the parts are alclad. So, I’m just going to clean the parts with MEK (methyl ethyl ketone) and then spray them with NAPA 7220 self-etching primer from a rattle can. Only mating surfaces and non-alclad parts will be primed. Of course, this may all change tomorrow if I’m not happy with my priming test run on HS-710 and HS-714.
Form priming, I'm cleaning parts with MEK and then using NAPA 7220 rattle can primer.
My first attempt at priming. I decided to start with a couple of small parts to see how well my system works.
Second Verse, Same As The First (10/20/09)
Posted by Ethan Jacoby in Construction, Empennage, Horizontal Stabilizer on October 20, 2009
1.7 Hours -
Today was basically a repeat of my last couple of days of work on the left HS, except it was on the right HS. I completed all right HS work up to match drilling the skin to all the ribs.
Everything went according to plan. However, I’m not entirely happy with how the right HS-405 to HS-702 to HS-710 attachment hole turned out. It isn’t as nice as the left side (which was just about perfect in my opinion), but it is within limits as far as edge distance, so I’m not going to fret over it too much. As other builders say, “build on!”
For greater details and a few pictures from the left side, see my posts from 10/9/09 and 10/18/09. Substitute “right” anywhere you see “left,” and you’ll know what I did.
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