Category Archives: hstab

A horizontal stabilizer emerges from the pile of parts

Rivet count:  811 + around 4 hundred = lots of rivets! (I totally lost count)

I really hate reading builders logs where they jump suddenly from a pile of bare parts to a finalized shiny component… Alas, I’m going to do exactly that.

The last two months have been rather scattered…. Our 2 month remodeling is now in its 4th month and we still have a lot to go.  I was dragooned into doing a lot of painting (confusion with the contractor on the provisions of the contract. Sigh.) and getting my daughter off to Ireland for school AND getting my wife out to Ireland to join her (with the drama of a missed flight to London, a lost passport, and missing the flight home).  This took a toll on my build time, but my wife now owes me big time!

So, I’ll add a running commentary on the photos that are roughly chronological:

Dimpling the rib flanges.  The vice grip dimpler from Cleaveland Tools is really nice for this.

2014-06-07 09.26.39

Attaching the ribs to the front spar.  Beginning to look like an airplane part!2014-06-07 11.00.09

A rare shot of me working…   You can see the rough cradles clamped to the bench that will hold the stabilizer for riveting.

2014-06-07 11.46.55

The nose ribs slid into place pretty nicely and clecoed in with little effort.

2014-06-07 13.01.38 2014-06-07 13.01.54

These rivets needed to be bucked. So slide a rivet in on the outside…2014-06-07 14.01.08

Use my tungsten bucking is taped up and wrapped in a shop towel in case I drop it (I did)   2014-06-07 14.01.35

Shooting some rivets!

2014-06-07 14.04.11


Some of the rivets are pulled down inside to make the final connection to the nose ribs.  The rivet puller has a rotating head.  Wasn’t sure at first how to get the puller in there, but clearly the engineers had thought this through for me.  It all fit.  I have a snazzy pneumatic puller, but it did not fit inside the stabilizer body.

2014-06-07 15.03.50 2014-06-07 15.04.28

Suddenly, this is looking like a real airplane part!

2014-06-07 15.11.09 2014-06-07 16.46.11 2014-06-14 11.01.29 2014-06-14 12.16.44

To get the rivets in the web assembly, it seemed easier to take things back out of the cradle.  You have to use some very long dome rivets.  They are (unsurprisingly) in the “Misc Rivet” paper bag.  Some rivets I shot because space was tight.  Some I was able to pneumatic squeezer, but a couple, it was just easier to get the hand squeezer in there.2014-06-14 15.45.52 2014-07-20 12.00.17 2014-07-20 12.13.48


Putting the rear spar on was a joy with the pneumatic puller.  I find that I tended to mess up rivets with the hand puller (its embarassing to have to drill out pull rivets, but I had to do that multiple times).  Either the final snap catches me off guard or I let the rivet ride out of the hole.  No problems with the air puller.  One quick trigger pull and it’s set!2014-07-20 14.02.29

Once the rear spar is in, it is just a matter of hitting up the 200 rivets holding the skin to the spar.  Pneumatic squeezer, I love you!

2014-07-20 14.34.14 2014-07-20 14.45.56



A new trophy for the wall!

2014-07-26 14.06.00

Next up, the elevators (and some cleanup work)


Smile.. I’m still making progress!

Rivet count: 603 + 46 + 130 = 779 rivets!

The blog has been dark for a month, but progress continued albeit slowly.

Lot’s going on back at the house and at my “real” job and that is distracting from my important work here at the factory!

The renovation at the house continues.  It was supposed to be done by now, but that isn’t how it works in real life.  Complicating matters my nephew and 2 of his friends are coming out for a visit this Wednesday AND my brother-in-law is visiting with his family on Thursday.  Sigh.  And I just quit my day job (Yike!). Hardly any time for building (but I do have a plane reserved for all three days of Memorial Day Weekend!).

The big news is that I started the horizontal stabilizer, so I get a new background picture.


April 26

So, I finally finished rolling the leading edge of the rudder.  It was hard to get the roll tight, but it all came together nicely in the end.  The edge lays up nice and tight except for one small gap.  The edge roller really helped get the skin to lay flat here.

2014-04-26 11.19.46


The next task was to figure out how to mount the thing on my wall!  I see lots of pictures of parts being built online.  And I see lots of pictures of parts hanging on walls online.  But I hardly see any pictures of how to hang the parts.  For the rudder, I cut a V shaped piece of wood on my table saw that fit neatly into the bottom.  Then I made a small shelf to hold the V piece. That made it a lot easier to mount on the wall.  I’m just using some plastic pipe strap to hold everything in place (and styrofoam blocks to keep it off the rough wall).

2014-04-26 13.10.56


With that out of the way, I starting digging out the parts for the horizontal stabilizer.  There are two big spars, some spar caps, and doubler plates to dig out to start.  At least this time I knew where to find the hinge brackets!  You start with the rear spar, but I decided to dress the edges of both spars before really digging into this part of the build.

2014-04-26 13.24.49

The spar is big.  It spans both my 5 foot tables.  The cut was very rough.  I filed down the worst of the edge with my file.  I managed to run the edge along my ScotchBrite wheel to get a smooth finish.  The lightening holes are a pain to smooth by hand, but I have some little wheels that fit in my electric drill that made pretty fast work of the deburring.

2014-04-26 14.06.59

I clecoed and match drilled the doubler plate and called it a day.

2014-04-26 15.14.48


April 29

I managed to sneak back out for some extra work on Sunday.  I got the rear spar and doubler plate primed.  Next I had to line up and match drill the hinges.  There are 4 pairs of hinge brackets (and a central one with a bearing riveted in).  I lettered them all to keep them straight.  I had to add some arrows to disambiguate the symmetric letters though.  The Sharpie shows through the primer (good!), so I placed the letters to be covered by the actual brackets.

2014-04-29 20.30.48

Lots of clecos to hold the doubler plate in place!

2014-04-29 20.40.11


Since the ribs get riveted in later, you have to be careful not to place certain rivets.  I bought a large roll of bright orange electrical tape that I use to mark these “do not rivet” spots.

2014-04-29 20.40.19


May 3rd

Another short day, but I did get a lot of things done.  I finally got a chance to get some rivets in.  There are too many to comfortably hand squeeze, so I fired up the pneumatic squeezer with the longeron yoke.  It worked really well for the doubler and for the hinge brackets.  46 rivets!

2014-05-03 11.40.30


The next task was to build a hinge bracket with a bearing inside.  For some reason, this was one part of the build that always looked really cool when I was researching building.  You need to take some care getting everything aligned, but it was not hard to match drill this.  Do remember to set an alignment mark so you can put it back together in the right order after deburring!


2014-05-03 12.06.21


One of the cardinal rules of riveting is to keep the piece from moving around.  Here also, we want to keep the “feet” of the brackets aligned.  Easy to clamp in place.  I used a 2×4 clamped to my table and then clamped the bracket where it was easy to reach.




2014-05-03 12.22.19


Voila!  The finished product!

2014-05-03 12.27.16

This then gets bolted to the spar.  This meant pouring over the manual to identify the correct bolts.  There is a chart in Section 5 that is helpful.

2014-05-03 12.36.11


I finally found the parts with the right lengths and proceeded to fit the bolts with my torque wrench.  Alas, I over-torqued at least one of the bolts.  This is dangerous because the bolt may break in flight.  For the 25 cents it takes to replace it, I’ll wait and try that one again.

The front spar is the next component on the list. I deburred the doubler and spar during the last step, so I was able to jump right into the build.  There are some spar caps that need to be trimmed and shaped.  I broke my band saw belt (again!) while cutting the very first one, so I used snips to get the other 7 ends.  The cuts made these awesome spirals.  I saved these for my daughter to make some shiny dangle earrings.

2014-05-03 15.44.56


Both my cuts and the factory finished edges were pretty rough, so I used my bastard file to do a rough edge dressing and then finished the edges on the polish wheel.


2014-05-03 16.12.27


May 17th

We picked up my daughter from college last weekend, so no time at the shop 😦

The big task for the day was to drill the spar caps.  They have to be carefully centered on the spar with 3/16″ beyond the last hole.  I got just enough edge clearance to make this work.  First you drill the (many!) holes through the spar web, then take off all the clecos and deburr.  Then you re-cleco the caps to the spar and do the spar webs. The instructions note that you should deburr between steps to ensure that you get a tight fit.  It was a lot of drilling and clecoing, but it all got done.  I didn’t take any pictures, but you have to countersink a lot of holes.  I carefully transferred the diagram from the instructions onto the spar to get the right holes.  The Sharpie marks wiped right off when I primed the spar, doubler, and caps.  Then it was time to cleco it back together for riveting.

2014-05-17 20.57.57

The orange wrapped clecos are where I’m not supposed to rivet yet.

My daughter was out at the shop (working on the earrings!) and helped with the clecoing.  She likes the rivet work.  Her great-grandmother was a bucker building airplanes in WW2.  Her grandfather (other side) was a MechE who build two planes.  I guess it is in her blood!

2014-05-17 20.30.53

May 18th

I was supposed to fly this day, but a front full of pop-up showers was coming in.  I was hoping to fly from 1-3pm or so…. Hmm.. KHPN had pop up showers starting at 3… perhaps I could start early and still make it to Orange County… No!  Pop up showers there starting at 1pm!  Well perhaps enough time for a quick run up to Poughkeepsie?  No, showers starting there at 2pm.  So I took a quick bike ride and headed out to the shop.  I spent the whole afternoon riveting the spar.  130 rivets or so…  7 different kinds (some flush, some domed with 3 different lengths).  I had to flip the spar over so I could get all the same types of rivets at the same time to minimize resetting the squeezer so much.

2014-05-18 16.45.39


Most went in just fine, but I had 4 problem rivets.  I had to drill all of them out (one of them I drilled out twice!).  My drilling out has measurably improved.  All of the rivets came out pretty easily and I did not enlarge any holes.

I read a lot about “smiley” rivets whilst doing my research.  I finally got one.  It was pretty, but I had to drill it out too 🙂

2014-05-18 15.36.51

The day was almost over, but at least I got a chance to start deburring the ribs.  Here are the nose ribs.  The cuts were very rough and had a distinct burr on the inside.   The polish wheel was a slow way to get these, so I used a file to rough them out.  I’ll finish the deburr and polish work next week when my nephew is out visiting.

2014-05-18 17.34.42