Still on the Empennage

Hi Gang! Yep, I'm still working the empennage. I never made it out to the welder to have my elevators' holes welded. I just can't afford it right now. Yep, money is that tight.

 

In the meantime, I decided to start working on the replacement trim tab. It's the same steps as before, but this time, I followed the plans more precisely. This time, I scuffed, cleaned and primed the areas where the end tabs will be bent as well as where the spar sits. I clecoed the bottom of the spar to the bottom of the tab skin and also put the trim tab control horn in place as well. I used the 2 horn pieces that came with the kit originally. Those have to be trimmed down a bit as there is a little extra on them. That's if you're using the manual trim I believe. Anyway, I match drilled all the holes on the bottom. Next I will remove the old trim tab from the left elevator and use the hinge as a guide for cutting the new hinge. I'll keep the old tab for a replacement, if I were to ever need it in the future. It's not in bad shape, it's just not perfect! Haha. I'm stopping here for tonight so I can get ready for the work week. No pix as it's the same stuff. I just hope this one turns out better.

Take Care & Thanks For Reading!

Day Total: 2.4  HOBBS Meter - 154.4

The Elevator that Won't Go Away...

Friday, August 16, 2013

I successfully rolled the leading edge of the right elevator today. It's similar to the rudder and left elevator. I'm pleased. I got all the rod end bearings set to 13/16" and torqued the stop nuts.

The next step was to install the elevators then trim the area of the HS skin where the counterweights need to travel through. Both sides of the HS skin, where the counterweight swings through, extend to a point where they don't allow the swinging action of the elevator to travel. This is inherent in the stamping of the aluminum from Van's. Here are some step-by-step pictures of the process to illustrate more clearly.   

HS Skin Interfering with Counterbalance Arm

Measuring to Clear Material for CB Arm

Material to Bottom Left is to be Removed

Starter Hole for Inside Radius

Hole Enlarged to Final Size for Inside Radius

First Cut. Leave a Little Material so You Can File it
to Where You Want the Edge Exactly

Second Cut & After Cleaning & Rounding Edges

After the Elevator is Installed, This is How It Should Swing

Another Shot Looking Straight Down

This needed to be done in 4 places, top left and right, then bottom left and right. First I needed to measure about 1/8" past the counterweight on the HS skin. Then I extended the line of the outboard edge of the HS skin. Once those two lines were drawn, I needed to set my radius for the inboard and outboard of the cuts. Next, I used snips to cut the excess metal away then file to break the edges and round the inside and outside corners. One down, three to go. Next, I remounted the left elevator to begin the process of setting the elevator "in trail". This means the elevator needs to be a perfect extension of the horizontal stabilizer and at a 0° up and down angle, nothing more. Here, I wanted the counterbalance arm to be even with the HS. I used a simple ratchet clamp to hold it in position. This is where I need the rod end bearings to be exact to the plans so the elevator horn sits exactly where it's supposed to, in conjunction with the opposite elevator and the elevator hinge bearing. If one bearing is not exact to the rest, the horn will sit in or out too far and won't line up properly and I could end up having my controls bind because they aren't in perfect alignment with each other. The measurement of the rod end bearings is 13/16" (7/8" Max). This measurement is from the elevator spar up to the middle of the eye of the rod bearing. Next, I needed to fabricate a bushing which would allow me to drill a hole in the elevator horn through the elevator hinge bearing. A bushing prevents the drill bit from enlarging or marring the hinge bearing. I wasn't able to find anything in my garage so off to Lowes to look for something that would work. I've seen a lot of builders us a drill bushing with a 1/4" outside diameter (OD) and 3/32" inside diameter (ID) purchased from McMaster-Carr. That's okay, if you're not on a budget. That little gem costs a little over $8, not including tax and shipping! I ended up at Home Depot in the specialty hardware drawer section (I couldn't find anything to suit at Lowes). I picked up a 1/4" OD x 3/16" ID aluminum bushing for 95¢, including tax, which will work perfectly. Because the hinge bearing is a hair under 1/4", I needed to turn the aluminum bushing on the ScotchBrite wheel a bit so it would fit. With that accomplished, I was ready to go with drilling.

The Bushing I Purchased From Home Depot
1/4" OD x 3/16" ID

Bushing in Place Ready for Drilling, But Not Yet!

I stopped here as somehow, I either misplaced my AN4-14A bold or I didn't pay attention to my inventory, noting that I received an AN3-14A bolt. This is a note for you future and current builders out there: KNOW YOUR HARDWARE SIZES! Because I was so new to this, I wasn't paying attention to my empennage inventory and making sure the bolt size corresponded with the inventory sheet. Without measuring and as far as I knew, the bolt LOOKED liked an AN4-14A bolt, but alas, it was not. Know the difference between and AN3 and an AN4 bolt. AN3 is 3/16" and  AN4 is 4/16" or 1/4" when you do the math. Needless to say, I need to order a bolt from Van's. No, I won't just order a bolt. That would be WAY too expensive after tax and shipping. I will also order the parts to make another trim tab. YES, I know what I said earlier, "It's just a trim tab people!". Well, I'm a perfectionist too. It looks ugly and I want to replace it. I'll consider this one practice.

Day Total: 3.6 hrs  HOBBS Meter - 148.5 hrs

Saturday, August 17, 2013

Today, I re-measured the rod end bearings to make sure I had everything lined up right. Measure twice (or 50 times), cut once. Right?! I'm waiting until Monday to order my bolt and trim tab parts and receive the order before I start drilling as I want to have the item in hand that needs to fit after drilling.

Day Total: .6 hrs  HOBBS Meter - 149.1 hrs

Monday, August 19, 2013

I placed my order today to Van's for the AN4-14A bolt along with my trim tab replacement parts.

Wednesday, August 21, 2013

I received my Van's order today! =8^)  I plan to get to work and finish the empennage Saturday. I'm anxious to put this behind me and get started on the wings!

Trim Tab Replacement Parts

Tuesday, August 27, 2013

Drilling! So, today I inserted the aluminum bushing into the elevator hinge bearing and went with the #27 drill bit (9/64") to start drilling the left elevator first. It looked like it went well so I took the left elevator off and installed the right one and continued to drill. Next, I used progressively larger bits until 1/4" was achieved. That done, I cleaned the holes then installed both elevators and went to install the AN4-14A bolt. Here's where things go awry. When installing the bolt, I realized that I achieved what many builders before me have accomplished, my holes are too close to the torque tube!

Bolt Shown Too Close to Torque Tube & Bolt Head
Filed Down to Fit in the Area Provided

I tried to do what others had done and that was to grind down one of the facets of the bolt head so it would sit close to the torque tube and still fit straight through the hole. It was very close, but it worked. Next was to see the fitment of the nut to the bolt. NO GO! Dammit! This hole seemed to be way too close. I couldn't even begin to thread the nut onto the bolt. Okay, my mind goes into overdrive here trying to figure out what my options are. I'm seeing dollar signs flying around with replacing the horns and all the work that is entailed with removing rivets... AAGGHHH!! Okay, 1) I can try filling with J-B Weld and try re-drilling. 2) I can get new parts and partially disassemble the elevators. 3) I can take the elevators to a professional welder and have the holes filled, grind them flat and try again. I opted for option 1. So I put a piece of packing tape on the outboard sides of the horns then stood them up vertically. I mixed some J-B Weld and dripped it into the holes. I let that cure overnight.

Hole Filled with J-B Weld. Hope This Works!

Day Total: 1.1 hrs  HOBBS Meter - 150.2 hrs

Wednesday, August 28, 2013
 Okay, the J-B Weld is more than cured by now so I decided to try drilling again. This time I made a jig, of sorts, by taking 2 pieces of angle aluminum and cutting them to about 1½" then marking 7/8" up from the bottom and drilling a 1/4" hole on each. My plan, which I'd read on another builder's site, was to stand the angles on each side of the rod bearing, adjust the rod bearings to 7/8" then trying a bolt through the whole shootin' match to get all the bearings consistent. The angle simulated the hinge brackets on the HS although, they would be standing from the elevator spar instead. 13/16" didn't seem to work well for me previously so I took the 7/8" max. measurement and used that as my mark. After getting all the rod bearings adjusted and set, I commenced drilling, AGAIN!

A note here: I did some research on what other builders have experienced on this task. Some do it the first time successfully and others seem to struggle quite a bit, like I am. Measuring the rod bearings seems to be a chore in some ways. The bearing in the middle rotates around making it difficult to get exactly straight. I did the eyeball method but that didn't seem to work very well for me. Others comment that consistency is difficult to achieve. I realized that 1/2 a turn makes a difference with the rod bearing's height. With that realization, it seems the only way one can make them all consistent is to make sure the direction of the platenuts is the same. How is this achieved you ask? Simple. Hold the platenuts in one hand and the rod bearing in the other with the bearing JUST inserted at the beginning of the screw. Now, turn the bearing in the reverse direction (loosen) until you hear or feel a 'click'. That is where the two starting threads meet or join to thread the two together. Now, make a mark on one end of the platenut and do the same with the rest and put the mark at the same location on all. Make sure to hold the rod bearing the same way with each one, this puts the start of the thread in the same spot every time. Mark the bearing if you need to as well to remember it's position in your hand. Once done, rivet all the platenuts in place with the marks going all the same direction. Now all the rod bearings will be consistent in height and not half a turn off from one another. I didn't do this on the elevators or rudder but plan to on the wings.

So, I set off drilling. I quickly discovered the J-B Weld is good for a great many things, but not as a hole filler to be re-drilled in steel. The bit was actually wandering over to the old hole as the J-B Weld is not as strong as steel. It's epoxy after all. Okay, now I'm extremely frustrated as this emp kit should have been done hours ago. No pictures for this little process. 

I cleaned up the holes by ScotchBrighting them, removing the powder coat around the holes, filing the remainder of the J-B Weld from the inside of the holes and clearing a little powder coat from the ends of the horns to ready them for welding (you need a ground point with the steel). I took my elevators to a local welder to see if they would be able to do them. He said to bring them by Wednesday as he was short-staffed. So, I'm waiting until then to take them.

Hole Cleaned Up & Ready to for a Fill Weld

Another note here: Although I did some welding in my youth in a shop class, I don't possess the skills necessary nor do I have the equipment to try this myself. I've read that TIG welding is better than MIG welding in that TIG has less spatter or spray and it is a cooler weld which is less likely to harden the steel horn which would be more difficult to drill later if it were hardened too much. I'll report the outcome a little later.

Day Total: .6 hrs  HOBBS Meter - 150.8 hrs

Saturday, August 31, 2013
Today, while waiting to take my elevators to be repaired by a professional welder, I decided to do a little work on the fiberglass elevator and rudder tips. Basically, I was just fitting them by marking the excess that needed to be trimmed around the counterbalance weights. So, I inserted them into their places and made marks right a the edge of the CB weight and made notches in both the elevator tips. I did the same for the rudder top tip. I also trimmed the excess of length (depth in this case) of the glass to make it fit into the space provided which will sit at or just above the inside rib line. I still need to trim the elevator tips for depth as well as the HS tips and the rudder bottom cap.

Elevator Tip in Place After Notching

Tip with Notch Cut Out for Clarity

That's it for now. Take Care & Thanks For Reading!

Day Total: 1.2 hrs  HOBBS Meter - 152.0 hrs

Left Elevator Complete

Sunday, August 4

Today was pretty straightforward, roll the leading edges of both elevators. Simple enough task. I only got one done today. :o( It seems a pretty simple task for 3 hours on one elevator. I was really taking my time to try and to a better job than I performed on the rudder. I think I succeeded. The left one turned out pretty nicely though. I only rolled one section at a time as trying to do them all at one time would have required me to be the Hulk!

I mentioned in an earlier post that I had bunged this elevator by leaving it hanging on one of the garage rafters then opening the door all the way, forgetting about the silly elevator hanging on for dear life and watching it to its best to land softly. HA! DUH!! Well, I decided the side of the skin with the major hangar rash was going to be the side that tucked in the inside of he roll. In other words, roll it first then it's brother would stay on the outside being riveted to the outside of the rash. This effort worked perfectly and covered up the rash pretty well. After forming the edge of the rash side, I got to work with my 3/4" steel pipe. Everything rolled pretty well. I think I would prefer to use the 3/4" pipe where I did toward the narrower section (outboard) of the elevator then transition to a 1" pipe on the wider part (inboard) of the elevator. This way the bends would line up a little better without having to do so much hand squeezing and manipulating.

I got everything (less the right elevator) done to my satisfaction. Additionally, I realized the rod bearings I had left to insert were not quite right. If you're at this stage, NOTE that the upper 2 rod bearings on the rudder are part number MD3614M and the lower bearing is part number MD3616M, a slightly larger size than the other two. So, I pulled the smaller -14M from the rudder bottom and put the larger -16M in and torqued it down. Now I had the 4 rod bearings (MD3614M) remaining and installed them into the elevators with their jam nuts and torqued them down. Even though the parts look the same, give them all scrutiny to make sure you're putting the right parts in the right locations.

Following are pictures of the left elevator rolling, riveting and completion.

Outboard Section, First Side Rolled

Outboard Second Side Rolled, Taped Into Place
& Clecoed. First Rivet Set

Outboard Section, Left Elevator Complete

Working Inboard with the Next Section

First Side Rolled. This was the Road Rash Part

A Better View of the Hangar Rash

This is a Better View of the Pipe in Place & Taped

Let's Roll! I Didn't Get Any Pix of the Roll Itself

The Start of the Taping to Get The Edges in Place

Zeroing in on the Hole Lineup for a Cleco

Once a Cleco is in Place, It Makes it a Little
Easier for the Next One to be Placed

Now to Just Work it Down the Line Until All
Holes are Fastened

All Clecos in Place with Tape to Help. Ready for
Drilling, Deburring & Setting the Rivets

This is What the Pop Rivets Look Like When
Set on the Inside.

All Done! The Inboard Section Looks a Bit
Skewed. I'll Massage This to be More Appealing

Now I just need to get to the right elevator and roll its edges, then install them on the horizontal stabilizer and check the swing, connect them in the middle and work with the counterweights to make them balanced. I love this project!

That's all for now. Take Care & Thanks For Reading!

Day Total: 3.0  HOBBS Meter - 144.8

Trim Tab Complete!

Okay, okay. I may have been a little harsh in my previous post regarding builders being overly picky and meticulous when it comes to the trim tab. I know that I'd like the perfect plane, in every aspect. Those little blemishes that occur along the way are what make our planes ours and very unique to us. I had much more difficulty with my trim tab than I'd expected. I think the issue is that the directions could be written a bit better with regular updates. Maybe this isn't the most cost effective way to do things at Van's, but it would help builders who succeed us with less headache. For instance, particularly on the trim tab, noting what areas should be dimpled and countersink BEFORE even bending the trim tab would be MOST beneficial and save on some time and aggravation. I know it would have for me. Ask me how I know this. Maybe I should start reading the sections entirely before embarking on a part. At times this isn't feasible, such as when you read before you build, sometimes it doesn't make sense as you're reading.

Masking for Priming Before Riveting Horns

Notice Anything? Yep, I Forgot to DIMPLE!
This Also Shows Rivet Sizes for Different Holes

Previously, I deburred, dimpled, countersunk and primed all the trim tab parts. I started with clecoing the trim tab back together. The directions tell you this then to rivet the bottom of the skin to the bottom of the flange and the trim tab horns. Well, you can't entirely cleco the trim tab and accomplish this. I needed to leave the upper skin unfastened to get either a squeezer or a bucking bar in the space. I riveted the horns and flange all in place and only had to rework 3 rivets.

I don't think I followed the directions in the right order but I basically got the hinge positioned in the previous steps, drilled and clecoed to the trim tab. Next, I positioned the trim tab on the elevator and marked the hinge position on the elevator laterally, figuring about 1/8" between the bent tabs areas. Next, I removed the forward part of the hinge and clamped it in place on the elevator. I started drilling on the outboard hole, then cleco, then drill every other hole, cleco then went back and finished drilling the rest of the holes. Next was marking the inboard skin edge on the hinge then trimming that area to match the skin when installed into position. I clecoed the forward part of the hinge back on the elevator and connected the trim tab with the hinge rod. Once this is in position, I used a small squeeze clamp to hold the trim tab in line with the elevator. This step is where alignment is needed to get the tab to follow the line of the trailing edge of the elevator and to tweak the tab to get it straight and follow the same line on the up and down axis. Per the directions, I clamped a piece of angel aluminum to the trailing edge of the elevator and aligned the tab to follow the same line and angle. Once it was straight, I put the clamp in position to hold it to the elevator then drilled the three #30 holes for the pull rivets on the bent tabs and put a couple clecos in. Next, I carefully removed the hinge rod and riveted the top of the tab with the hinge in place. After that, I put the pull rivets (CS4-4) into the bent tabs. Then I needed to figure where the rivets would go on the other end of the trim tab so as not to interfere with the rivets needed on the elevators bent tabs. I put the trim tab back on to mark where I would put those rivet so they were offset from each other.

Setting Position for Tweaking the Trim Tab

Marking Bent Tab Area for Pull Rivets

Next, I riveted the forward part of the hinge elevator and VIOLA! The trim tab is is done!!! Directions tell you that the pin/rod for the hinge is not long enough and that you'll get one that fits the way it should for bending and positioning in place to be wire tied to the elevator. That one will come with the fuselage kit. I need to make a punch list of things I need to go back an complete. Up to this point, there hasn't been much. Things like this hinge rod, torque sealing certain nuts and bolts as well as any other things that don't get checked off the direction list right away.

Trim Tab Complete, Except for the Hinge Rod

Another Shot of the Completed Trim Tab

I agree that the trim tab is very small, but a major pain in the @$$! It does take patience. If you're getting frustrated, STEP BACK, TAKE A BREATH! Just go slow. This thing doesn't and WON'T be done tomorrow, at least not at this stage. While riveting my hinge to the trim tab, I didn't have my squeeze set right and bent one of the hinge sleeves. That took 10 minutes or so to get worked out. But turned out fine. I put another marred spot in the skin while bucking one of the hard-to-get-to rivets. The bar was set funny inside and I didn't have the rivet gun on very well. Needless to say, the skin is quite ugly in that spot.

The Marred Area From the Bucking Bar

The Same Area, Different Angle. It Has A
Tin Can Effect if Pushed From Both Sides

If it turns out that I'm just not that happy with it, maybe I'll make another later. It's pretty straight and true. I saw another builder talk about the flange inside not being very well fabricated and it causing one side of the skin to bow when pulled into position. Mine is doing that as well. There's a bit of a bow on one side and pretty straight on the other. I'm going to leave it alone for now.

I semi-installed the trim tab motor to get a feel for how the push rod will be positioned when it's in it's final position. There will be some trimming needed for clearance where the rod exits the elevator skin. It shouldn't be a big issue, a little fine trimming, filing and cleaning. I'll probably work the fiberglass tips later with the other fiberglass. I want/need to take the fabrication course that the EAA offers (SportAir Workshops) before I venture into uncharted territory. I'm not sure if I'm going with the seamless look or screwing the tips on. The latter gives better accessibility for any fixes, changes or repairs. The seamless gives a nicer look as well as better waterproofing for the inside of the wings and empennage. I'm going to weigh the options and read what VAF members and other bloggers have done to see what the consensus is. Next will be rolling the leading edges of the left and right elevators. Fun stuff... NOT! Well, it kinda is. =8^P

That's all for now. Take Care & Thanks For Reading!

Day Total: 5.9  HOBBS Meter - 141.8

... and the Building Resumes!

Sunday, July 28

Finally, back to work! Today, I started back on the trim tab. I put it in the bending brake last session and I went too far. I tried carefully to bend it back out, no easy task. I managed though. There are a total of 4 tabs (2 on each end) that require bending 91°. Make sure you pay close attention here. The lower tab is bent FIRST, then the upper tab. This way, you won't get water leaking or draining into the tab in the rain. When you start this process, the plans show you starting with the whole trim tab upside down. It makes it a little confusing. In this case, you bend the top tab (lower) down first, then the bottom (upper) tab up second. You'll get the picture with the inboard section as there are 3 rivet holes on one tab that need to be on the outside when finished bending. Do both ends the same. I read of many builders ordering an extra trim tab set just because most use the first one as practice and aren't happy with the outcome. C'mon! It's just a trim tab. Once it gets sanded, cleaned, primed and painted, I don't think they really turn out that bad. I know, there are some perfectionists out there. I'm one too. You can always order a kit later and do it again if it's really that bad. I think mine turned out pretty well. I may have bent a little too much of the tabs on one end, but I think it'll be fine.

Outboard End of Trim Tab, Decent Bending

Inboard End of Trim Tab. A Little Too Much Metal Bent

Basically, I took a piece of 1/2" particle board about 7"x3", figured the angle of my trim tab with the spar in place, which is right about 10°. Then I cut it at that angle. I'm not too fond of my small, cheap, name-brand band saw's ability to cut a nice, straight line. So, I used a piece of 1/4" metal, used for my dimpling in tight spaces, and clamped it to the board on the angle of my cut and used a small hand saw against the edge of the metal and made a real nice cut. In retrospect, it doesn't matter what angle it's cut. Basically, it just needs to be greater than 10° but less than that which would open the trim tab up too far. You can use the distance that when the end tabs are bent, they're separated by 1/8" to 1/4". If you follow the 10° method, make sure to leave a small enough angle at the trailing edge to fit into the space of the trim tab. I used double-sided Scotch tape on both sides of the inside block and a strip on the outside for the outer block. This keeps things mostly in place. I should have put the whole assembly on a non-slip piece of mat on top of the work surface to prevent slipping but it "slipped" my mind. Haha, bad joke. Another thought would also be to use some tape on the work surface to hold the entire trim tab in place. I clamped the whole block assembly to the bench with ratchet clamps as well as clamping the trim tab on the leading edge to the edge of the work bench. Let the bending commence. You want to turn your pressure down on your rivet gun so you don't go too wild and bend the crap out of the tabs. Use a block of wood to get started on the bend, per the plans. Once you get the tab closer to its final position, you can use just your gun to flatten it out pretty nicely, all along the edge, back and forth until you're satisfied. Yes, you'll notice here that this is the same exercise used on the left elevator. I previously used foam tape. BAD idea. Don't go this route. It's is too thick and gives too much and is a royal pain to remove from your jig parts. It was a bit overkill. Just follow the directions for preparing and you should do fine.

Next, I cleco'd the trim tab spar (E-607PP) to the bottom surface of the tab skin. Then I got the electric trim tab motor trim tab horns (E-617EEPP-1 and E-618EEPP-1), clamped them together, used a clevis pin in the holes for alignment and clecoed them as a whole part to the skin. Needed are a couple holes drilled for one of the horn parts as the skin is without. That's why it's necessary to clamp the 2 horn parts together, using them as a template, of sorts. Pretty simple here. After fitting the parts in place, I match drilled the holes through the trim tab horns.

Spar in Place

Elect. Trim Tab Motor Control Horns in Place

Another View of the Trim Tab Horns Connected as One

I stopped here for the night as the next step is working with the piano hinge. I wanted to do a little research on this one. I'd certainly like to get this right on the first try.

Day Total: 1.9 hrs  HOBBS Meter - 132.2 hrs

Tuesday, July 30

Tonight, I started working on a few bends and dings that mysteriously showed up on the leading edge of the left elevator. Okay, I'll confess. I had put the elevator up out of the way, hanging the counterweight end on one of the rafters. I had the garage door open half way for air and later decided to open the door all the way. I wasn't paying attention and the door pushed the elevator off the rafter and bent a couple of areas along the leading edge. So, I took a little time to straighten them out. The edge hasn't been rolled yet, making it pretty easy to ding the edges up a bit. I was able to straighten the worst offenders pretty well. There were only about 3 or 4 issues. The elevator itself looks pretty straight and true so I don't anticipate any issues with it later. It'll be interesting to see the leading edge after it's rolled and riveted. I'll try to post a couple pictures after the roll.

The Smallest of All Dings. Needs a Bit More Work

Ding #2. I Hope This Cleans Up Better After Edge Rolling

Ding #3 More Outboard of #2

The Top of Ding #3. I Hope This Ends Up Rolling Ok

Next on the list was to work the hinge for the trim tab. I checked a couple other builder logs for info. Interestingly, the few I looked at didn't have much in the way of information. So I decided to follow Van's plans the best I could. Sometimes they can be a bit confusing. I have a habit of over-thinking things at times. It took me a while to comprehend that the hinge DOES NOT go between the skin and spars. I don't know why I had this in my head, but once things "clicked", it was much easier to move forward. Over-thinking I guess! The hinge rivets to the innermost area to the skin and spars.

Hinge Measured, Marked & Clamped in Place

Showing 3/8" From Rivet to Inboard Hinge Edge

Trim Tab Hinge Drilled & Cleco'd in Place

I started by marking the hinge at 1/4" in from the trailing edge of the trim tab side of the hinge the length of the hinge. I did the same for the elevator side as well. This line is used as a site line through the rivet holes for alignment and distance. Then, I made a mark on the hinge for the area that would be removed (waste) on the inboard edge. That distance is 3/8" from the left-most rivet hole to the end of the hinge on the trim tab side, per the plans. After trimming the hinge, I clamped it in place on the bottom of the trim tab spar, making sure the site line is centered in the rivet line. Then I match drilled the holes starting with the inboard hole first, clecoing it then drilling every other hole and clecoing while removing the clamps along the way. Then I went back to finish the rest of the holes. I then put the other half of the hinge back together with its mate. The next step is to take apart the trim tab assembly, machine countersink the spar and dimple the trim tab upper holes and work more on the control horns. Stopping here tonight.

Day Total: 2.0  HOBBS Meter - 134.2

Wednesday, July 31

Tonight saw drilling the rest of the holes in the trim tab, countersinking and dimpling the trim tab spar. Next was to disassemble and the usual "Lather, Rinse, Repeat" with deburring, dimpling and priming. Not too much tonight, just enough to keep busy on the project, KPR! (Keep Pounding Rivets), and... edge finishing, deburring, dimpling and priming. KPR for short. =8^)

That's all for now. Take Care & Thanks For Reading!

Day Total: 1.7  HOBBS Meter - 135.9