Feb 03, 2021     08-12 - Horizontal Stabilizer Final Assembly 2 - (25.7 hours)       Category: 8 Horiz Stab

1/26/2021 – 2.3 hours
Final horizontal stabilizer assembly continued with riveting the skins to the front spar. The HS is still in the cradle, so you have to reach deep inside the skins to buck the rivets on the front spar just like nose ribs previously. To help access the spar inside the skins, I removed the clecos from the ribs to provide a little more space for my arm to get into the skin cavity. I can get to most of the rivets, but there are a couple of areas where you need really strong, long, thin arms. Specifically, the area between the second and third ribs from the inboard edge is really tight. The ribs are close together so you have to reach straight down. I found that I could not hold my small bucking bar effectively in this space for a few rivets, so I opened up the special RV-14 elevator bucking bar. This bar is long and narrow, and it easily reached the rivets in this area. The bar is a little unwieldly, but it is the best solution for me to buck those rivets. The other thing to keep in mind is three different rivet lengths are used to attach the skin to the front spar, so pay attention to the rivet schedule in the plans and take your time to ensure you have the right rivet for the hole you are working on. I managed to set the 47 rivets for the top right skin to the spar in this work session.
[3x Rivet Gun, Swivel Flat (Mushroom) Set, BB-6 and BB-7 Tungsten Bucking Bars, #40 Drill, Pin Punch, 4.5” Diagonal Cutting Pliers, Special RV-14 Elevator Bucking Bar]

1/27/2021 – 2.9 hours
The work on riveting the horizontal stabilizer skins to the front spar flanges continued. I finished all of the rivets on the top left and right HS skins, and moved around to the bottom skins. I am working from the center of each skin (top right, top left, bottom right, bottom left) toward the outboard and inboard edges. I am riveting roughly every other hole with clecos holding things tight in the other holes. I ended up replacing 2 rivets – one didn't get set flush to the skin because I pushed harder with the bucking bar than the rivet gun, and the other was at a rib intersection and ended up with a really bad shop head. I've gotten really good at drilling out rivets (not sure that's the legacy I'm going for!), and both came out damage free.
[3x Rivet Gun, Swivel Flat (Mushroom) Set, BB-6 and BB-7 Tungsten Bucking Bars, #40 Drill, Pin Punch, 4.5” Diagonal Cutting Pliers]

1/28/2021 – 2.6 hours
Riveting the horizontal stabilizer skins to the front HS spar is complete. The biggest issue was not completely setting three of the rivets. It was pretty easy to tell when this happened because the sound of the rivet gun was more “hollow” than normal and the shop head appeared to form extremely quickly. Picking up on these clues after just a handful of taps made the process of removing the rivets very easy, and all of the unacceptable rivets came out cleanly without damaging the hole.
[3x Rivet Gun, Swivel Flat (Mushroom) Set, BB-6 and BB-7 Tungsten Bucking Bars, #40 Drill, Pin Punch, 4.5” Diagonal Cutting Pliers]

1/30/2021 – 7.3 hours
I riveted the horizontal stabilizer bottom skins to the HS ribs and stringer assembly. The plans have you work up the ribs from the front spar toward the aft edge of the HS, with an intermediate stop at the stringer level to rivet the stringers in place. Bucking some of the rivets near the front spar are a little tight, just like getting to the rivets on the spar itself, but it gets easier as you get further up the ribs. One particularly tricky area with the bucking bar is the two holes just forward of the stringer. The stringer blocks your vision in that area, so those rivets have to be bucked by feel. You can try to see how you did afterward by slipping a phone camera into that area. I set the rivets on the most inboard and out outboard ribs with the pneumatic squeezer.
[3x Rivet Gun, Swivel Flat (Mushroom) Set, BB-6 and BB-7 Tungsten Bucking Bars, Pneumatic Squeezer with 1 1/2" yoke, 1/8” and 1/4" Flat Rivet Sets]

1/31/2021 – 5.4 hours
Riveting the horizontal stabilizer skins to the inspar ribs and stingers is complete. There weren't any surprises or revelations during this session, but I did have to wear some thin protective work gloves to provide some relief to my knuckles. I did notice on the bottom skins that the area near the intersection of the stringers and the second inboard rib is especially susceptible to minor dings from the rivet gun. The gun didn't walk any more than any other area, so my guess is the damage comes from the fact the geometry of the substructure and the relative narrow stringer and web flanges compared to the width of the flat set on the rivet gun. The dings are noticeable if you look from the right angle, but almost imperceptible to feel. I received a tip that you can work out minor blemishes like this by rubbing a spoon on the backside of the damaged area to gradually unbend the skin. I tried that, and it did ease the blemishes a bit. I may spend a little more time with the spoon before I install the rear spar, which will effectively make the area between the inspar ribs inaccessible.
[3x Rivet Gun, Swivel Flat (Mushroom) Set, BB-6 and BB-7 Tungsten Bucking Bars, Pneumatic Squeezer with 1 1/2" yoke, 1/8” and 1/4" Flat Rivet Sets]

2/2/2021 – 2.7 hours
The final step in the horizontal stabilizer build is to install and rivet the rear spar into the assembly. The plans repeat the warning to ensure the spar is oriented correctly and not installed upside. After confirming, double-checking, and triple-checking the orientation of the rear spar, I cleco'd it to the tails of the inspar ribs along the length of the horizontal stabilizer. The spar gets riveted to the two outboard and two inboard ribs with AN470AD4 rivets, with the manufactured head on the spar for clearance with the elevators. The rear spar is riveted to the intermediate ribs with LP4-3 blind (pop) rivets. I completed the pop rivets with the hand rivet puller. There is no problem with access to the rivets with the puller, and the all went in without any issues. I plan to tackle the AN470 rivets as well as the flush AN426AD3 rivets for the skin to spar connect with the pneumatic squeezer in the next work session to finish the horizontal stabilizer.

2/3/2021 – 2.5 hours
The final steps to finish the horizontal stabilizer are complete! I started this session by riveting the inboard and outboard inspar ribs to the rear spar with the pneumatic squeezer. The standard 3” yoke provided good access to the rivets on the inboard ribs, and I set the rivet manufactured head on the spar in accordance with the instructions. There is a set of 3 holes on the rear spar next to each of the inboard ribs that are empty. I went through the horizontal stabilizer plans to ensure I had not missed a step, and then found that those holes are used to attach the horizontal stabilizer to the empennage later in the build. Leaving empty holes feels strange, but it is correct in this case. The build ended by attaching the skins to the rear spar. After a quick change to a flat squeezer set, I finished this task working from the middle of each skin to the inboard and outboard edges. It takes 196 AN426AD3-4 rivets to attach the skins, but the job went quickly without any major issues.
[Pneumatic Squeezer with Standard 3” Yoke, 1/8” and 1/4" flat squeezer sets, 1/8” cupped squeezer set]

  Jan 25, 2021     08-11 - Horizontal Stabilizer Final Assembly 1 - (9.4 hours)       Category: 8 Horiz Stab

1/24/2021 – 6.7 hours
The complete horizontal stabilizer started coming together with the assembly of key elements of the skeleton within the HS skins. Once the left and right skins were secured in their cradles, the two center nose ribs in each skin was cleco'd into place. Riveting the nose ribs requires a long reach inside the skins with the bucking bar, so you'll need a riveting partner unless you have an extra-long reach. I managed to rivet solo, but the very front set of rivets were very difficult to buck. Each nose rib Has 10 flush rivets to set (5 top and bottom) for a total of 40. That makes for a lot of long reaches and climbing up and down the step stool. Falling is a major hazard during this step – both in terms of hurting yourself and destroying your skins if you happen to fall on them, so make sure your step stool is secure! Another hazard is dropping the bucking bar and denting your skins from the inside. I put a small towel down in the nose crease of the skin to cushion a potential drop just in case.

I started with the aft hole and worked my way forward through the first four rivets of each rib. The riveting geometry on the fifth, forward-most hole was tricky; so I saved those for later. After setting the four rivets on one side of the ribs, I turned the skins around in the cradles to rivet the other side. Do not try to hurry through this step. It pays to take your time and really concentrate on setting each individual rivet. Also, the rib flanges will force you to set half of the rivets right-handed and half left-handed. I found a good technique for both hands was to use short controlled bursts on the rivet gun to keep it from walking off target, check your results with the bucking bar, and reset and shoot another short burst.

The forward-most rivet on each rib sits near the table at a downward angle when the piece is in the cradles. To get a better angle, I tilted the cradles back and inserted a 2x4 under the front of the cradles. This helped get some clearance from the table for the gun and oriented the rivet closer to horizontal so I could get decent leverage on it. The other issue is the front rivet is in a tight area. I ended up with minor dings near a couple of front rivets where the bucking bar strayed a little too close to the skins during the riveting process. No showstoppers, but not perfect either.

With the nose ribs riveted in place, I inserted the front spar assembly into the skins and cleco'd them in place. I was especially careful to align the holes in the front spar web with the corresponding holes in the riveted nose ribs. The outer ribs are pretty easy to align since you can see the nose rib flanges through lightning holes in the spar. The two inner ribs are not visible, so I checked alignment by clecoing them first and then lifting the spar slightly. If the skins moved with the spar, I had successfully cleco'd the spar to the ribs. If not, I missed with the clecos and had to try again to align them correctly. A long pick helped ensure they were aligned. I finished clecoing the skins to the front spar assembly making sure that all of the ribs and stringers aligned correctly.

The final task of this session was to rivet the front spar to the nose ribs using blind (pop) rivets. The spar is attached to each of the 4 ribs with 3 blind rivets. Clearance for the rivet puller is very limited, and it is very hard to create the leverage needed to fully set the rivet in the confined space. Again, make sure your step stool and footing are secure so you can safely generate the leverage you need.
[3x Rivet Gun with Swivel Flat Set, Bucking Bar, Clamps, Blind Rivet Puller, 3/32 and 1/8 Clecos, Cleco Pliers]

1/25/2021 – 2.7 hours
I turned my attention to the most inboard and outboard nose ribs to complete this step. There is a note in the plans that the inboard nose ribs can be riveted to the assembly after everything else is completed, but it was easy enough to unclamp the cradles and lay them back to get access to the rivets that connect the nose ribs to the front spar and inboard in-spar ribs. It turns out that was the only easy part of this session. The inboard nose ribs are riveted to the spar and inboard in-spar ribs with AN470AD4-7 and 4-8 rivets. Those are the largest rivets used so far in the build, and they take a lot of pressure with the rivet gun and bucking bar to set. The process is further complicated because you don't have access to the rivet with a straight rivet set. The answer is to use a double-offset 1/8” cupped rivet set with the pressure turned up on the gun. I set the rivet with the factory head on the nose rib side, which gave better access to the rivet than tring to go from the other side. That also follows the general rule to set the factory head on the thinnest piece of material. Bucking bar access to the shop head side of the rivet wasn't too bad, but the inspar ribs are set at an angle and you need to use the angled edge of the bucking bar to get the bucking face parallel to the spar and perpendicular to the rivet. It took nearly two hours to set the 10 rivets (five per rib).

After securing the inboard nose ribs to the spar assembly, I finished this step with the pneumatic squeezer to set the flush rivets on the inboard and outboard nose ribs. The flush rivets went pretty well, and all the nose rib rivets are done. Now on to riveting the forward spar to the skins!
[3x Rivet Gun (increased pressure) with 1/8” Cupped Double Offset Rivet Set, Angled Bucking Bar, Pneumatic Squeezer with 1 ���nd 1/4" Flat Rivet Sets]

  Jan 23, 2021     08-10 - Horizontal Stabilizer Front Spar Assembly - (4.4 hours)       Category: 8 Horiz Stab

1/22/2021 – 0.1 hours
The first step of this section was an easy way to end the day. All I had to do was take the front spar off the shelf and orient the spar with the top flange facing up. After that, I retrieved two of the nose ribs, and cleco'd one to each end of the spar as shown in the plans.

1/23/2021 – 4.3 hours
With another nice day in store, I started by preparing the horizontal stabilizer skins for priming. I also took the opportunity to touch up some areas on the front and rear spars as well as some of the in-spar and nose ribs that had not been primed very well the first time around. After letting the parts dry for a few hours, I cleco'd all of the in-spar ribs and the stringer web assembly to the front spar. It was great to finally see all of the pieces starting to come together. I then riveted the in-spar ribs, except for the 2 inboard ribs, to the front spar. I started with the 3 outboard ribs on each side. They are attached with 3 rivets that I could access pretty easily with the 2 1/2" longeron yoke. I set the top and center rivets for each of the 6 ribs (3 outboard ribs on each side), and then flipped the assembly over to set the final rivet. I put the factory head of the rivets on the rib side since the ribs are made from much thinner material than the spar. I moved on to the next set of ribs, 2 on each side, that fit between the stringers in the stringer web assembly and are attached with 4 rivets. The 2 center rivets on each rib are the same length as the ones used for the other in-spar ribs, but the top and bottom rivets on these ribs are longer since they go through the spar caps as well as the spar. I set the two center rivets first on each rib, then set the top rivets, flipped the entire assembly over, and set the final rivet. At the end of this step the two outboard nose ribs, and the 10 outboard in-spar ribs were riveted to the front spar. The final two inboard ribs get riveted later since they share common rivets with the nose ribs.
[Grey Scotch Brite Pad, Bon Ami Cleanser, Dupli-Color Self-Etching Automotive Primer (Green – Rattle Can),Pneumatic Squeezer with 2 1/2" Longeron Yoke, 1/8” Cupped Squeezer Set, and 1/4" Flat Squeezer Set]

  Jan 22, 2021     08-09 - Horizontal Stabilizer Stringer Web Assembly - (1.6 hours)       Category: 8 Horiz Stab

1/22/2021 -- 1.6 hours
The internal structure of the horizontal stabilizer started coming together with the stringer web assembly. The first step was to rivet the stringer web to the 2 inboard in-spar ribs. The angle of the forward and aft flanges of those ribs were modified previously since they are not perpendicular to the forward and aft spars like the rest of the ribs. The rivet locations were easily accessible with the pneumatic squeezer. I decided to set the factory head of the rivets on the stringer web since that piece is thinner than the stringers. The stringers were cleco'd into the assembly after the web was riveted to the ribs, and they were also riveted into place. The four outboard rivets were a little tight with the pneumatic squeezer, but I managed to squeeze those rivets by carefully spreading the angle of the ribs open slightly. The trickiest part of this step is figuring out the orientation of the stringers. It is not instantly obvious in the drawing, but it is very clear when the stringers are inserted incorrectly in the assembly.
[Pneumatic Squeezer with 2 1/2" Longeron Yoke, 1/8” Cupped Squeezer Set, and 1/4" Flat Squeezer Set]

  Jan 22, 2021     08-08 - Horizontal Stabilizer Skin Preparation - (15.4 hours)       Category: 8 Horiz Stab

1/17/2021 -- 5.6 hours
This was a deceptively easy-looking step on paper, but execution takes a lot longer. I started by removing the blue vinyl from the two HS skins and deburring the edges. I used a 3M wet/dry sandpaper product for the initial deburring that worked really well to remove the tooling marks from the edges. I then followed up with an edge-deburring tool and a final light pass with the sandpaper. With the edges deburred and the “no-dimple” holes marked, I moved on to dimpling. Each skin has 400+ holes to dimple, so this takes awhile! I finished dimpling one skin, which was enough for one day. A complicating factor in this step is the fact that the continuous skin that is pre-formed at the leading edge leads to very awkward access to the holes with the C-Frame and some close-quarters holes toward the leading edge. A second set of hands to hold the skin out of the way would be ideal, but the family was out of town and I was working solo. I compensated by using three strips of duct tape and folded towels to hold the opposite skin back so I could dimple effectively. That worked really well, and I will do that again on the second skin. I also had my first major dimple disaster. I didn't notice the dimple die had slipped out of the hole when I was wrestling with the skin (before I came up with the duct tape / towel idea), and I ended up puncturing the skin right next to the hole I was supposed to dimple. I “undimpled” the error with a flat set, deburred the hole I made and radiused it where it intersected the hole I was supposed to dimple, and dimpled the correct hole. Deburring and removing the sharp corners from the unintended hole should mitigate future cracking issues in this area, and the hole will end up beneath the fuselage fairing so there is no real cosmetic issue. I'll let me tech counselor take a look to see if I need to do anything else with this error. Lesson-learned…
[Edge Deburring Tool, Sandpaper, Scotch Brite Flap Wheel, C-Frame, 3/32 Standard Dimple Dies]

1/18/2021 – 4.6 hours
Another nice day means another opportunity to prime parts! It was a bit windy, but I managed to get all of the HS skeleton parts prepped and primed. It looks like the weather this weekend will be nice, too; so I'll get the HS skins prepped and primed then. With the priming out of the way, I returned to dimpling the HS skins. This continued the process of the previous work session, and almost all of the holes were dimpled successfully. The most forward holes are too tight for access with the C-Frame, so I'll get those in the next session with a close-quarters dimple die.
[Grey Scotch Brite Pad, Bon Ami Cleanser, Dupli-Color Self-Etching Automotive Primer (Green – Rattle Can), C-Frame, 3/32 Standard Dimple Dies]

1/20/2021 – 1.3 hours
The C-Frame cannot access the forward-most holes in the horizontal stabilizer skins, so I had to go to my 3/32 Close Quarters dimple die set. I only used this dimple die set once before on my practice project with mediocre results, so I was not anxious to use it on the HS skins. The Close Quarters dimple dies have a hole in the center for a mandrel (aka nail), and the mandrel is inserted into a blind rivet puller to apply the pressure to form the dimple. The idea is to put enough pressure on the die to have them contact the skin, but it is not necessary to use so much force that the mandrel breaks. I very patiently squeezed the Close Quarter dimpler on each of the 16 forward most HS holes, and I was pleasantly surprised with the very good results. The dimples are not quite as well formed as the ones created with the C-frame, but they are more than acceptable to seat the flush rivets. Definitely a win!
[Close Quarters 3/32 Dimple Die Set, Blind Rivet (pop) puller, Nails]

1/21/2021 – 2.0 hours
The countersinking process began with the horizontal stabilizer forward spar. I clamped the HS forward spar to my work bench, and countersank all of the #40 holes in the flanges (top and bottom) to receive .025” thick dimpled skins. I have a small piece of .025” aluminum with #30 and #40 dimpled holes that I used as a template to set the depth of the countersink cage. I found that setting the countersink cage .009” (9 clicks) beyond flush gave the correct depth to hold the dimple firmly without any play and allow the skin to sit flush against the spar. I countersank all of the holes on the top flange of the spar, then flipped it over and re-clamped it to couintersink the holes on the bottom flange.
[Air Drill, Microstop Countersink Cage, 3/32” 3-Flute Countersink Cutter, Clamps)

1/22/2021 – 1.9 hours
This section concluded by countersinking all of the #40 holes in the top and bottom flanges of the aft spar and the #40 holes in the stringers. I reset the countersink cutter to .009” beyond flush, clamped the spar to the workbench, and countersunk the holes from the center of the spar out to the ends. Countersinking the stringers was similar, but I could not easily clamp the stringers down. Instead, I put a scrap of wood under the stringer flange and clamped that to the bench. The stringers are much shorter than the spars, so countersinking went pretty quickly.
[Air Drill, Microstop Countersink Cage, 3/32” 3-Flute Countersink Cutter, Clamps)

  Jan 16, 2021     08-07 - Horizontal Stabilizer Skeleton Drilling and Dimpling - (3.4 hours)       Category: 8 Horiz Stab

1/16/2021 – 3.4 hours
The horizontal stabilizer front spar came off the shelf to match drill a couple of holes into the modified nose rib aft flanges and a hole in the modified in-spar ribs forward flange. I had not worked with the HS spars in awhile, so I was glad that I had marked the top flange and direction. That made orienting the spar to the ribs quick and reduced the chance of inadvertently doing things upside down! I wrapped up this section by dimpling most of the #40 holes in the nose and in-spar ribs.
[#30 Drill, Pneumatic Squeezer, Reduced Diameter 3/32 Dimple Dies]

  Jan 15, 2021     08-06 - Horizontal Stabilizer Part Preparation - (12.2 hours)       Category: 8 Horiz Stab

1/10/2021 – 3.4 hours
This work session focused on deburring the skeleton parts for the horizontal stabilizer. There are 20 new parts, including nose ribs and in-spar ribs, with a lot of edges, flanges, and lightening holes to deburr. I used the deburring blade tool and Scotch Brite flap wheel to debur the lightening holes in each piece. I completed deburring the edges of one set of in-spar ribs. I also laid out the horizontal stabilizer build cradles using a nose rib and inspar rib as a template.
[Deburring blade, Scotch Brite Flap Wheel, 6” 3M Cut-n-Polish Wheel, Maroon Scotch Brite Hand Pad, File]

1/12/2021 – 2.8 hours
After taking an evening off for the college football championship, I returned to deburring the HS skeleton parts. I purchased a set of needle files at a local hardware store to help with deburring the flange gaps and bends. The needle files were perfectly sized to get into those tight areas, and I was very happy with them for light deburring tasks. The flat needle file was also really good at removing the CNC tooling marks on the flange edges. Deburring with the needle files added to my process still takes a lot of time and effort, but it is much easier and more effective than without. It definitely does not replace deburring blades and Scotch Brite pads, but is a very nice addition to the deburring tool box.
[Deburring blades, 6” 3M Cut-n-Polish Wheel, Maroon Scotch Brite Hand Pad, Flat and Round Needle Files]

1/13/2021 – 4.0 hours
The initial deburring of all the HS skeleton parts is complete. I will take a short deburring break before inspecting each part to ensure I haven't missed anything. The next step in the part preparation process is to ensure the flanges are square and flute as needed to align the predrilled holes in the parts. The plans also call for changing the angle of end flanges on two nose ribs and two in-spar ribs. These will be the center ribs of the HS structure which is angled to allow mating with the empennage.
[Deburring blades, 6” and 1” 3M Cut-n-Polish Wheels, Maroon Scotch Brite Hand Pad, Flat and Round Needle Files, Hand Seamer, Fluting Pliers, Carpenter Square, Protractor]

1/14/2021 – 1.2 hours
The work session today was pretty short to inspect all of the HS skeleton parts and ensure they are deburred properly, the flanges are square and adjusted per the plans, and the flanges are fluted to align all the pre-drilled holes. I have about 4 days left until the next nice day for priming outside, so I'm trying to get the skeleton and skin pieces drilled, deburred, and dimpled by then. The edges and flanges of the skeleton pieces only need some minor deburring touch-up, and they will be ready for priming after the holes are drilled, deburred, and dimpled. I finished this session by re-drawing the outlines of the nose rib / inspar rib template on the piece of 2' x 4' x 5/8” particle board for the HS cradles.
[Scotch Brite Flap Wheel, Round Needle File, Maroon Scotch Brite Hand Pad]

1/15/2021 – 0.8 hours
The final task of this section is to make construction cradles for the horizontal stabilizer. I used a hand jigsaw to cut out the templates that I had drawn previously, and attached 1” x 2” cleats to the bottoms of the cradles to let them stand free and to provide and area to clamp them to the table. I lined the cut area with simple straps made from duct tape to help secure the skins in the cradle and protect them from damage while I'm working on them. With any luck, I'll also be able to use the cradles to store the HS when it is finished.
[Jigsaw, Circular Saw, Drill, Screwdriver]

  Jan 01, 2021     08-05 - Front Horizontal Stabilizer Spar Riveting - (4.4 hours)       Category: 8 Horiz Stab

12/31/2020 – 2.1 hours
I started riveting the front spar, doubler, and spar caps with the rivet gun and bucking bar for additional hand riveting practice. This went well, and I feel much more comfortable with the gun and bucking bar. My bucking arm started to get tired after a couple of hours, and I decided to switch to the pneumatic squeezer to finish the job the following day. I had one rivet near the end where the bucking bar came off the rivet and made a stair-step pattern down the shop head. That rivet was successfully removed and replaced with one set with the pneumatic squeezer.
[3X Rivet Gun, Tungsten Bucking Bar, 1/8” Cupped Rivet Set, C-Clamps]

1/1/2021 – 2.3 hours
Happy New Year! I finished the front spar riveting before the New Years football games started. I set up the pneumatic squeezer to set the remaining AN426 and AN 470 rivets in the assembly. I worked from the center of the assembly toward each end with good results. The primary complicating factor of this step is keeping track of the 5 different rivet lengths/mfg heads. The rivet schedule only shows half of the rivets, since the other side is a mirror image, and it pays to take your time and make sure you are using the correct rivet called out for each hole. There are also several holes that do not get riveted yet, and those were marked off with tape to help keep everything straight.
[Pneumatic Squeezer, 1/8” Flat Squeezer Set, 1/4" Flat Squeezer Set, 1/8” Cupped Squeezer Set]

  Dec 31, 2020     08-04 - Front Horizontal Stabilizer Spar Preparation - (9.2 hours) Category: 8 Horiz Stab

12/26/2020 – 2.5 hours
The front spar preparation started with deburring the edges and lightening holes of the spar. I also deburred the edges of the front spar doubler, even though that step is not specifically mentioned in the plans. After deburring, it was time to drill a lot of holes into the spar caps that were trimmed and deburred in the previous step. I put alignment marks 3/16” from each end of each spar cap, and nested them inside the top and bottom flanges of the spar. I then used several 1/2" and 1” cleco clamps to hold the spar caps in position. The spar caps were match-drilled and cleco'd to the spar web.
[Edge Deburring Tool, Scotch Brite Flap Wheel, Flat File, 1” Cut and Polish Wheel, Rubber Mallet, #30 Drill, Cleco Clamps]

12/27/2020 – 3.6 hours
Match drilling the spar caps continued with the 3/32 holes in the flanges of the spar. The spar caps were removed from the spar and the holes in the spar web and spar cap were thoroughly deburred before the spar caps were reattached to match drill the flange holes. I used the cleco clams as well as clecos in the spar web to hold the spar caps in place for drilling. After that, there were roughly 100 holes (times 4 – 2 sides to the spar caps and 2 – sides to the spar flanges) that had to be deburred.
[Hole Deburring Tool, #40 Drill, Cleco Clamps]

12-29-2020 – 0.4 hours
This was a quick session to get things ready for final drilling and countersinking. The main task was to cleco the front spar doubler and spar caps to the spar. This was a case where the plans did not specifically say to cleco the spar caps in place, but it is implied since the final drilling of the spar and doubler also goes through the spar cap.

12/31/2020 – 2.7 hours
Final drilling and match drilling have become fairly standard operations by now. This step included final drilling the #30, #12, and 1/4" holes common to the spar and doubler. I like to use a drill block to help keep me drilling perpendicular to the part, especially when working with thick aluminum pieces like the doubler / spar / spar cap combo. I machine countersunk the 12 holes in the doubler called out in the plans as well as the 9 holes each in the top and bottom flanges of the spar for flush rivets. The process ended by disassembling the parts, deburring the holes, and reassembling them in preparation for riveting.
[#30, #12, and 1/4" Drill; #30 Countersink; #40 Countersink; Microstop Countersink Cage]

  Dec 29, 2020     08-03 - Rear Horizontal Stabilizer Spar Assembly - (4.8 hours) Category: 8 Horiz Stab

12/24/2020 – 1.0 hours
The process of assembling the Flange Bearing to the Inboard Hinge Brackets was unique to this point in the build and very interesting. The flange bearing has six holes in the round flange around the bearing that gets sandwiched and riveted between the two inboard hinge brackets. The holes between the brackets and the bearing were final drilled as well as the mounting holes in the hinge brackets. The parts were then deburred and riveted together.
[#12 and #30 Drill, Hole Deburing Tool, Pneumatic Squeezer with 1/8” Cupped and Flat Squeezer sets]

12/26/2020 – 3.2 hours
The focus shifted from the rear spar to the preparation of the front spar caps and horizontal stabilizer stringers. There are a total of 4 parts (2 each spar caps and stringers), and both ends of each piece need to be trimmed. The parts were then deburred in preparation for the next step.
[Dremel Metal Cutting Wheel, Flat File, 6” Cut and Polish Wheel, Maroon Scotch Brite Pad]

12/28/2020 0.6 hours
With the rear spar components primed and riveted, the final step was to bolt the inboard hinge bracket assembly to the rear spar assembly. The AN3-5A bolts went through the bracket side of the assembly, and were secured with NAS washers and MS21042-3 self-locking nuts on the doubler side of the spar. The torque specified for the AN3 bolt and MS21042-3 nut is 28 in-lb. I set up my never-before-used torque wrench to 28 in-lb and started cranking away on the first nut. I chose to ignore the following gem in Section 5 of the plans, “When using the 1/4 in. drive snap-over type torque wrench we recommend practicing with it off the aircraft first until you get the feel of the particular tool's snap-over feature since it can be rather light depending on the size of the fastener.” The predictable result was that I snapped the bolt because I didn't recognize the VERY light snap-over feel of the new torque wrench. Luckily another local builder has given me an extra AN3-5A bolt. The other 3 bolts were installed without any issues, and I have re-learned the lesson that there is a lot of great info in section 5 as long as you choose to use it :-) !
[In-Lb Torque Wrench, Crescent Wrench]

  Dec 28, 2020     08-02 - Rear Horizontal Stabilizer Spar Preparation - (8.6 hours)       Category: 8 Horiz Stab

12/23/2020 – 3.9 hours
Work on the horizontal stabilizer started with preparation of the rear HS spar. The first critical step is to identify and mark the top of the spar – that warning is repeated at least 3 times in the plans! I deburred the spar edges and holes (including the lightening holes) and the rear spar doubler edges and holes. The CNC machine that cuts the parts leaves a tool mark on the edges about every 3 inches that needs to be filed off before the edges can be finished. The maroon Scotch Brite flap wheel in my battery drill worked great on the lightening holes. I did inadvertently waste time by deburing the holes in the spar web and the doubler – I'll have to do that again after I final drill those holes in the next step.
[Flat and round files, Maroon Scotch Brite Flap Wheel, Deburring Tools, Rubber Mallet]

12/24/2020 – 2.8 hours
The next step in the preparation of the rear Horizontal Stabilizer was to match drill and final drill all of the holes common to the spar, doubler, and hinge brackets. I marked the locations and orientations of all the parts so they can be reassembled in the same spot later, and then all the holes were deburred. After priming, the rear spar will be ready for final assembly.
[#12 and #30 Drill, Microstop Countersink Cage, Hole Deburring Tool]

12/28/2020 – 1.9 hours
I riveted the rear spar doubler and the hinge brackets to the horizontal stabilizer rear spar. I had considered using the pneumatic squeezer with the longeron yoke to squeeze the rivets, but I decided to buck the rivets with the rivet gun and bucking bar instead. The AN-470 rivets for this step was ideal to get some practice with the rivet gun and bucking bar. I clamped the rear spar to the work bench and set all of the rivets with the manufactured head on the spar side. I was very pleased with the results, and I have a lot more confidence with the rivet gun! I continued the riveting session on the hinge brackets (manufactured (domed) head on the hinge brackets), again with good results from the gun/bar.
[3X Rivet Gun, Tungsten Bucking Bar, 1/8” Cupped Rivet Set, C-Clamps]

  Dec 23, 2020     08-01 - Horizontal Stabilizer Plans - (2.6 hours) Category: 8 Horiz Stab

12/22/2020 – 1.6 hours
I reached a stopping point on the rudder while I wait for a replacement shear clip and skin stiffener, so I moved on to the plans for the horizontal stabilizer. One new step that I hadn't done previously was to go through the RV-14 Revisions and Changes posted on Van's website to ensure that my plans are up to date. It turns out there was a recent change to this section of the plans related to “labeling steps to help prevent builder errors”. I compared the plans on the website to my printed plans to ensure I had the latest before starting to prepare parts and assembly.

12/23/2020 – 1.0 hours
I finished my detailed review of the plans prior to starting work on the horizontal stabilizer. This section introduces a few new parts including in-spar and nose ribs, spar caps, stringers, and a stringer web. It also relies more on traditional rivet gun and bucking bar techniques to attach the skins to the internal structure, so I'll have to practice some before I get to that point. I am excited to start on this section because it is essentially a preview of how the wings will come together. Big Fun!