Aileron Bracket Assembly

Changed it up a bit tonight!  I am still holding off on riveting the wing skins until my wife is free to help, which is kinda rare with a 4 year old!  So, I decided to go ahead and get the aileron brackets assembled and ready. I also grabbed all the parts from the SB 16-03-28 kit, as I am going to address this now during the build.   I did grab a timelapse of the work, heres the overhead view:

Vans ships the brackets in a sub-kit complete with its own plans on how to assemble the brackets.  The main assembly plans just shows us the already-assembled bracket and where it goes on the wing.  Heres a photo of me studying the plans and the sub-kit instructions.

I had taken some time previously to look over the plans and do some rough assembly of these things just to get an idea. So I dug into it, and got them clecoed together, and then match drilled all the holes.

Once I had the holes match drilled in the brackets, I took the assemblies over to the wing and clecoed them in place so that I could match drill the holes for the brackets with the rear spar, as well as the doublers that shipped in the service bulletin kit.  This SB includes a several doubler plates that get mounted on the rear spar side of where the inboard aileron brackets mount, and serve to reinforce this area against cracking.  It’s good to get this done while building as its super easy to access.  You can see the doublers no the leading edge side of the rear spar (interior of the wing):

You’ll notice in the photos above how the webs that are sticking up in those photos interfere with the rivet holes in the rear spar web where the bottom skin rivets.  I marked on these webs with a sharpie where I thought it would be good to remove a small portion of the web to make clearance for those rivets.  Later on, I used my bench grinder to grind off this area that I had marked.  At this point, the aileron brackets for both wings had been fully match drilled.

Next it was time to deburr the edges and the holes in these parts to get the ready for final assembly.  I made sure to keep the left wing and right wings parts separate on my bench, and then disassembled the brackets, removed the plastic and then smoothed all the edges of each part on the scotchbrite wheel.  After that, I deburred all of the holes in each part.  Reading the plans, it tells us there is only a tolerance of .005″ gap between the two plates of the aileron bracket.  I decided to NOT spray AKZO primer on these surfaces because I didn’t want to get too big of a gap, so I am going to alodine them.  That will give PLENTY of corrosion protection and be well within the tolerances for gaps. So off to the Alumaprep33 and then Alodine baths!

Instead of wasting time, waiting on the parts to soak in their Alodine baths, I decided to go ahead and match drlll the W-724 aileron gap seals and the W-721 flap braces to the rear spar, since these are my next step.  So, I clecoed them into their respective places on the rear spar, in every other hole, and then match drilled both of them to the rear spar.  There’s a little trimming work needed on W-721 flap brace, and the holes will need deburred.  I am also going to prime these braces and gap seals with AKZO.

The Aileron brackets came out looking very nice when Alodined! The plans do point out to prime the mating surface of the angle aluminum, so I dried the parts and hit them some self-etching primer, right over the top of the alodine.  I figured this extra little bit of corrosion protection wont hurt on these angle brackets, and since they are not part of the “sandwhich” for the actual bracket, there isnt a worry of clearance here.

Thats it for tonights work session.  I did capture a closeup timelapse, that you can see below.  I will let the alodine cure overnight, as well as the rattle can primer, and then start the work of riveting these brackets together, so they can be riveted to the rear spar, after I get the top skins riveted.  I only have a couple more work sessions left (priming bottom skins, priming gap seals and braces, etc) before I will be at a critical path waiting on the top skins to get riveted.

Google Photos Link: https://photos.app.goo.gl/afYpbZAai8ZKnYMTA

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Hours worked: 3.0

Dimpling Right Wing Top Skins

Another good session today!  I managed to get the right wing to the same point as the left wing, its skin dimpled and clecoed in place, waiting on riveting.  Here is the overhead timelapse of the work:

And here’s the “mobile” camera  view thats a little closer up:

I pulled the right wing top skins from the paint booth, and got to work removing the blue plastic from the rivet lines on the outside of the skins.  I used the dull soldering iron and straight edge trick for this on both skins.

After that, I setup the DRDT-2 for a dimpling session on these skins, and masked off the holes that wont be getting dimpled per the plans.  After a decent round of work, both the right wing top skins were dimpled and ready to get clecoed onto the skeleton.

I then clecoe’d the inboard skin to the right wing skeleton, and realized I forgot to dimple the wing walk doubler!  So I made a quick trip back to the DRDT-2 and got it all dimpled and ready.  Then I slipped the wing walk doubler behind the top skin and clecoed everything in place.  I started. by clecoed the very forward edge of the skin to the main spar flange, then working from the center rib of each skin, I clecoed every other hole.  Then I placed the outboard skin and did the same with it.  I had JUST enough clecos to get every other hole on this wing, minus about 8 holes.  I double checked that all the lap joints and skin intersections looked good and took pride in the fact I have what looks like two wings!

Heres the back side of the right wing for completeness:

Yeap.  That last picture is every single one of my 3/32″ clecos, all being used.  Both wings top skins are now ready to be riveted, and they are at the same spot in the build again.  Instead of calling it a day, I decided to go ahead and get the pitot mount plates and  braces aldoined, because I could use a small dish to contain the parts.  So, I scuffed them up a little, and the put them in bath of Alumaprep33 for 10 minutes.

After a quick rinse of the parts and the plastic dish, I put them into a aldoine bath for a other 15 minutes.  Then rinsed them off.  They came out looking great!

The sunlight from the window washed the camera photo, but they are indeed a nice and golden color.  I’ll leave them alodined and skip priming them, since they will have a good corrosion protection from the alodine.  I am going to call some of the local chrome shops Monday morning to see about sending my pitot mast off to be chromed.

At this point, I am ready to rivet on both the top skins for both wings.  I’ll wait till I have help to do that, and I think I’ll use the backriveting technique since I have the extra long back rivet set and bucking bar for it.  There’s still a few things I can probably do in the mean time, I’ll read up and see whats doable until riveting time.  Thats it for today!

Google Photos Link:

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Hours Worked: 3.0

Installing the Pitot Mount

This is going to be a long blog, with lots of pictures.  So sit back and get ready.  I got a LOT accomplished today.  It started with the arrival of a few tools I needed.  A nibbling tool, and a Tekton 1/4″ torque wrench.  I wanted to get the Gretz Aero pitot mount installed, and the hole for it cut in the left wing before I riveted on the top skins.  Here’s the ovehead timelapse of the work:

And here is a closeup view, that I moved around the shop as I worked to get a better view of what I was doing:

So, lets dig in to the details.  I took a lot of photos because there is a lot of “custom work”, outside of the normal Vans plans, since Vans only has you use a small piece of aluminum tubing for the pitot.  I decided to go with a nice heated pitot that has an AOA sensor in it as well, since this airplane will be used for IFR work.   I elected to go with a Gretz Aero pitot mount, because I like how the mast screwed in to the wing via reinforcement plates.  This makes the entire pitot assembly (tube and mount) fully serviceable in the future.  In the end, I really like the Gretz mount and highly recommend it.  Here’s what you get in the kit:

The instructions are pretty decent, and I gave them a good read before starting this session, since the mount came in a few days ago.  Gretz tells us we may need to file down the openings in the reinforcement plate and washer plates due to slight manufacturing tolerences in the mast itself.  They also make these holes very close tolerance to give a very nice finish, but it requires a little filing work on the customers end.  I actually like this, as I ended up with a very tight fitting assembly that is going to look fantastic.  I just had to use an assortment of files to get the mast tube to fit in the plates first.  A half-round bastard file was what I used most, followed by some small round files.

There was a lot of gentle filing, test fitting, filing some more, test fitting, etc, etc, etc.  But eventually I wound up with the pitot mast fitting very snugly into the plates:

Next, its time to fit the reinforcment plate (the one with the little joggle on it) to the wing skeleton, and start drilling some holes.  The plate does not have any rivet holes, as its designed for the builder to fit it whereever they want.  I chose to mount my pitot just one bay outboard of the access hole for the aileron bell crank.  This is pretty typical of most RV-7’s, and I figured if it works well for all the others, it should me too.  Its far enough away from the tie down ring it shouldnt be a problem, and also close enough to the access hole I can easily service it if needed.  The reinforcment plate was designed for a Vans RV airplane, so the joggle on it was just perfect, with only a little forming needing to fit snug.  Next, I measured where I wanted the rivet line to be.  I found the center of the joggle, and marked the rivet line with a sharpie, and used this same distance for the other three sides as well.  I then used a Noxon center-punch to mark the first hole location for reference.

I wanted to verify the lines on the joggle part lined up nicely on the spar flange, and that I didn’t have any interference issues, so I grabbed a cleco clamp, and clamped the plate on to the spar flange, making sure to line up the blue sharpie line with the rivet holes in the main spar flange, then I checked that I had plenty of clearance from the leading edge skin rivets.  This looks good so far.

And here’s what it looks like from the bottom side of the wing.  Yes, I did indeed write “PITOT” on my wing, so I would make sure I got it in the right rib bays.  It also lets you get a better idea of where I am installing this thing on the wing.

 

Happy with how its looking so far, its time to start drilling the holes into the reinforcement plate!  Gretz gives us a rough layout of where the holes need to be, so I used that as reference on how to lay mine out.  I used the spot I center punched to drill the first hole, then I cleco’d the reinforcement plate back onto the spar, lined up the blue sharpie line and then clamped it into place so I could back drill the other holes using the spar flange as my guide. Back drilling from the spar scratched some primer off, so I’ll need to touch that up, no biggie.

   

With those 4 holes done for the main spar flange on the plates joggle, its time to get the rest of the holes done.  This was pretty easy as I used a rivet spacing fan to help.  I’ve had this tool for a long time, but never really used it much, until tonight.  It worked great.  Its a nice tool to make very evenly spaced rivet holes!  Using the outer hole I just drilled into the joggle, I clecoed the rivet fan in place, and spread it out until I had the 5th hole in the spacer lined up perfectly with my centerline I drew earlier.  This gave me 5 very evenly space holes to use.

I center punched the end hole using the spacer fan as a guide, the drilled it with a #40 drill.  To get the other three holes perfect, I clecoed the fan at both ends, and then center punched the other three holes using the spacer fan as my guide.  Then I removed the fan, and drilled the holes to #40.

I just followed this same procedure all the way around the plate until I had all my rivet holes drilled and nicely spaced.  However, Van’s used a different spacing on the spar flange, and I am butting up against the back of the rib so my bottom holes don’t line up exactly to my top holes, but thats only cosmetic, and wont be seen once its all painted anyways.

Now its time to make the small reinforcement bracket that is used to brace the reinforcement plate to the nearest rib.  Gretz plans tells us to use .032″ to make the support brace / bracket, and luckily I had a sheet of .032″ in my scrap bucket to use.  I clecoed the bottom skin to the skeleton, and then clecoed the reinforcement plate onto the spar flange so I could measure and fabricate the brace.

I made my brace by measuring and cutting a piece of the .032″ aluminum sheet and then bending it to make a 90 degree bracket in my bench vise.  Then I clamped it in place against the rib, making sure it was sitting nice and flush with the reinforcement plate.  This took a few times of bending, fitting, and bending, fitting again, before I got to what I liked.

   

I wanted to backdrill the bottom wing skin to the reinforcement plate before I drilled the bracket to make sure the plate was completely flush against the skin.  So, I back drilled the wing skin, using the reinforcement plate as my guide, and clecoed the holes as soon as I was done to make sure it didn’t move.  Then, I clamped the brace into place against the rib and lined it up with the reinforcement plate.  At this point, I had all the holes back drilled into the SKIN from the plate. An important point, since once I had the brace clamped on, I needed to go to the other side of the wing, and backdrill the brace using the new holes in the skin and reinforcement plate as my guide.

After I had the brace drilled and clecoed to the reinforcement plate / skin assembly, I back drilled the plate to the wing rib.  I decided to make these holes BETWEEN the holes I just drilled into the plate from the bracket.  This would give me clearance to rivet the holes when I do the final assembly and riveting.

I’m committed at this point.  The holes are drilled into the skin for the plate, now its time to cut out the hole for the pitot mast into the skin.  I removed the skin and the reinforcement plate from the wing, and set it up on my bench.  To cut out the streamlined shape of the mast, I decided to drill some holes, and use a nibbling tool.  I picked out a drill bit that gave me a decent shape for the small end of the mast hole, I don’t recall the size, I was eyeballing what would get me close.  I think it was a 3/8 bit?  I used the same bit to drill the hole in the large end, and opened the hole up using a uni-bit.

Notice I did leave the reinforcement plate clecoed on, and marked the hole with a thick sharpie.  I am using this as my template for the skin cutout..  The uni-bit was able to get really close to the blue sharpie.  Next up I grabbed the new nibbling tool and slowly and gently nibbled out along the blue line.  I found that I was able to place the nibbling bit up from the bottom of the skin, and use the shoulder created by the reinforcement plate as a guide for the nibbler, and this worked out very good.  Its a great tool for this work, and it costs like 14 bucks!

I worked very slowly and took very small nibbles to make sure I didn’t go to far.  I highly recommend using this tool for doing this sort of complex hole cutting.  Here is a photo showing where I am sticking the nibbler UP from the bottom side of the skin and using the cutting head to rest on the reinforcement plate to use as a guide.  Eventually I had a very nice, rough cut that required very little filing and finish work

Then, I removed the reinforcement plate, and used a combination of files to smooth out the edges of this new hole, and then widen it ever so slightly to fit the pitot mast.  Very similar to how I had to file down the plates to fit the mast at the first of this build session.  The time lapse show this work much better.  Eventually I ended up with a very close fitting hole that will look great for the pitot mount to stick through on the skin!  Here is how it looks mid-process:

    

To make sure everything is correct before I do the last bit of finish work, I clecoed everything back onto the wing skeleton and fit the pitot mast in its new home.  It turned out really slick! I am really happy with this.

     

Here is how it looks on the inside of the wing.  This is going to be very easy to service if I ever need to.  It’s also very strong with all those plates and braces securing it to the skeleton of the wing, its not just dangling and flopping around from being attached to the skin or an access plate.  This is solid.

Then, I dissambled everything, and cleaned up all the holes with some files, deburring tools and scotchbrite.  I made sure to get the hole I nibbled in the skin for the mast nice and smooth with no sharp corners to start a crack.  These parts are now ready for assembly.  I am going to alodine all the plates and braces for the pitot, and then I am considering sending off the pitot mast itself to be chromed at a local old-school hot rod shop thats been doing chrome since the 50’s.  I think a chrome pitot mount will look very nice, and be very durable.  Maybe it won’t cost much?  I’ll report on it later.

I had a few loose ends to finish up tonight.  My Tekton 1/4″ torque wrench delivered today and MAN is this thing nice! I am now a huge Tekton fan. This wrench was only about $43 bucks from Amazon:  https://amzn.to/33n1Ce2  I love it.  I needed to torque down the fuel tank Z-bracket bolts on the main spar web.  I decided to go with 40 inch/lbs, as the spec for this is 28 inch/lbs plus the drag of the nutplate.  I measured about 14 inch/lbs of drag so I went with 40 inch/lbs and I think thats good.  The Tekton has a nice “thunk” when it hits the torque spec.  Once I had all the bolts torqued, I marked them with some orange TorqueSeal. I did this for both the left and right wings.  The tanks are now mounted!!

Lastly, I decided to go ahead and cleco the left wing outboard top skin to the skeleton, as the left wing is now 100% ready to have its top skins riveted on.  It feels amazing! I am planning on getting Tammy to help me do this, maybe the right wing too, later on this week. It’s looking like a wing now!

That’s it for today.  This was a LONG work session, and I got a ton completed.  I’m stoked to have my pitot mount done, and I’m looking forward to all the rest of the work now.  I still need to get the right wing skin dimpled, and clecoed on, so that maybe work for tomorrow.  Then I’ll alodine the pitot mount parts, and send the mast off for chrome plating.   I think I will go ahead and get the bottom skins primed now as well.  They won’t get riveted until WAY later right before mounting on the fuselage, as I still haven’t decided which autopilot I’m going with, or lighting.

Google Photos Link:  https://photos.app.goo.gl/K5VLPd1bZoX4G2Uq9

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Hours Worked: 5.0

Dimpling Left Wing Top Skins

Pretty simple build log entry tonight.  I got both the top skins dimpled for the left wing, and even got the inboard skin clecoed in place.  Heres a couple of time lapse videos of the session:

Heres a little bit better closeup view.  When I started clecoing to the skeleton, I moved the camera over to get a good view of that too 🙂

The session started by pulling the skins from the paint booth, they’ve been curing for about 2 days now.  Then I setup my DRDT-2 dimpler and removed the blue plastic from the rivet lines on the skins.  I used a dull tipped soldering iron to make the removal process a bit easier.

You can see on that right side of the photo above where I sprayed the AKZO primer on the outside facing part of the skin.  This is where the inboard skin and outboard skins overlap, so I wanted to make sure there was adequate corrosion protection in this lap joint. Yeah, I sprayed a little to far outside the lap joint, but its no big deal since I plan on painting the airplane anyways.  Once the plastic was removed, I masked off a few holes that will be used to attach the fuselage fairing, I dont want to dimple these just yet. Then I used the DRDT-2 to dimple all the skins.  After a little bit of easy work, I got both the left wing top skins dimpled:

I also needed to dimple the wing walk doubler as it goes under the inboard skin, between the skin and the rib.  So I clecoed it in place to verify I had the orientation right, then made some referenc marks. After that I got it dimpled on the DRDT-2

I decided to go ahead and get the inboard skin clecoed in place tonight, including the wing walk doubler.  This skin won’t cause any issues with me installing the pitot mast tomorrow, and there is nothing else left to do on that inboard side, so I clecoed the inboard skin in place, and slipped the wing walk doubler behind the skin and clecoed every other hole, so its ready for riveting.  I’ll need to find a helper to get the skins riveted.  Then I took a little time to ponder my wiring installations, pitot and AOA plumbing etc.   I’ll work on getting the pitot mast installed in the next session, I’ve got a nibbler on the way to make cutting the skin out a little easier.

Google Photos Link: https://photos.app.goo.gl/jwmJWH9aYqCfNxuW8

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Hours Worked: 2.25

Mounting the Left Fuel Tank

Delivery day! I got my shipment in from SteinAir, which included my pitot mast, as well as a few 18 gauge ring terminals that I needed to attach the wire to the fuel level sender on the back baffle of the fuel tank.  Here’s the goods:

I did capture a few timelapse videos, heres the one from the overhead that captured the full session. I had a few visitors and helpers there for a bit :). My little girl Acacia was playing and my wife was working just outside the shop in her flower garden.

I started off by crimping the proper sized ring terminal onto my 18 gauge Tezfel wire.  I picked up a few different sizes just in case.

I inserted a plastic bushing in one of the existing holes in the spar web.  It was there from the factory, and in a darn near perfect location.  The plastic bushing (I don’t recall the exact sorry unfortunately) will keep the wire from chaffing.  I will leave enough of a service loop that the tank can be removed.  I’ll also use a pin connector so it will slip through the plastic bushing as well.

Then I sat the tank on the spar, threaded the wire through the bushing and shimmied the tank into place.  I then threaded the AN3-4A bolts with their AN960-10L washers into the Z-brackets nutplates.  I am only going finger tight for now, as I need to pick up a 1/4″ drive torque wrench.  I would use my beam torque wrench but it’s gonna be awkward to use in these spaces. Following that, I threaded all of the AN509-8R8 screws into the tanks skin. Theres a bunch of these things.  I did however, tighten these screws down, and I did dab a little Boelube onto the threads to help thread into the brand new nutplates and maybe prevent corrosion.  Here’s a timelapse and closeup of the actual mounting work.

And a little bit later, I have the tank mounted!  I’ll torque the bolts down on both wings once I get a torque wrench, and then apply some torque seal to them.  Now both wings are at the same progress in the build.  They are both ready for the top skins to be riveted. I think I will move on to getting the pitot mast done first, then dimple the skins for riveting.  Soon they will be off the wing stands and into the cradles for the final control surface mounting!

Thats it for tonight. I need to pick up a nibbler for the wing skins so I can neatly cut out a hole in the skin for the pitot mast.  I’ll pick up a torque wrench then as well.  Here’s all the photos from tonight:

Google Photos Link: https://photos.app.goo.gl/GWRntZieJ6w7FUjP8

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Hours worked: 1.25

Priming the Top Wing Skins

I was able to get all 4 top wing skins primed tonight. They’re ready for dimpling, and then riveting!  It looks like my pitot mast should be here in a day or so, which is pretty good timing, as thats about when I’ll need to get it installed.  I grabbed a couple of time lapses for this build session.  The first one is the entire session, the other is a shorter on thats close up of me scuffing and cleaning the skins.

I started out by scuffing the 4 top wing skins.  I had a bright idea of borrowing my wifes orbital sander and seeing if a scotchbrite pad would stick to the velccro attachment…..AND IT DID!!!

This made is SOOOOOOO much easier to scuff these skins! Just check that timelapse.  Each skin was very nicely scuffed in a few minutes with very little work.  I did go back over them with the pad in my hands to touch up a few spots, but the sander left a very nice and uniform scuffed surface for priming.  After that, I cleaned the skins with MEK and acetone, using a clean paper towel on each wipe till it came up clean.  Then off to the paint booth they went.  Heres a timelapse and closeup of this work:

And here’s what a skin looks like from using the scotchbrite pad on a sander:

I mixed up 8 ounces of AKZO primer, which seemed to be a little more than I needed for the 4 skins.  Not much excess though, maybe 1 ounce?  As the AKZO was doing its 30 minute kick off, I setup the paint booth, and then donned my bunny suit.  I wound up making some covers for my shoes with paper towels and masking tape. It worked better than I thought!

Heres my obligatory selfie in a bunny suit to show I am doing the work 🙂 I need to replace the dust filters on the respirator chemical cartridges.  This bunny suit is also a little worn.  I might be able to get the rest of the priming sessions for the wings done with it though.

 

Then, I sprayed the skins with AKZO in the booth, and did my clean up.  I need to spend some time on this paint gun, as my nozzles are getting a bit clogged causing an uneven spray pattern.  This is of course a $10 spray gun, so it might be worth trashing and buying new?  I have sprayed with this thing a bunch so far, and its give great service up till now.  Here’s how the skins turned out:

Thats it for tonight.  I’ll let these cure for a day or so, then start the work of dimpling them.  After that, they’ll be ready to go on the wing skeleton for final riveting!

Google Photos Link: https://photos.app.goo.gl/oXxBseB8UpVbXRKYA

Hours Worked: 2.5

Deburring and Preparing the Top Wing Skins

Time to get the top skins ready for priming.  I’m waiting on my pitot mast and some terminal connectors for the left wing, so I decided to go ahead and start prepping the top skins so they’ll be ready for priming then dimpling.  I am priming first, THEN dimpling because its SOOOO much easier on my scotchbrite pads, and I am running low on pads. Hopefully these’ll last until I order my fuselage.  I got a timelapse of this session:

I started out by gathering up all the top wing skins.  I first went to work on the W-727 wing walk doublers by rounding all the corners and then deburring all the holes.  These holes were backdrilled into this sheet, so they needed conventional deburring.  Then I took all the blue plastic off of these doublers. After those, I did the same to the inboard and outboard top skins for the left and right wings.  I rounded their corners, and then used a bastard file to knock down all the rough edges from the sheering.  After I all the rough high points on the skin edges, I went over the edges with a scotchbrite pad to completely smooth the edges nicely, on all 4 skins.

The next step was to remove all the blue plastic from the inside surface of the skins, since I am planning on priming the insides with AKZO.  Once I had the plastic removed from each of the skins, I used the edge break tool to for a nice edge break on the skin edges that will be overlapping either another piece of skin or the main spar and ribs.  This will make a nice flush joint.

That has all 4 of the large top skins done, so I set them over to the side for now.  I’ll be scuffing and priming the inside skin surface in a later build session.  For now, I wanted to go ahead and alodine the wing walk doublers.  My reasoning is to save some weight, and to provide these doublers a nice layer of corrosion protection.  Since they will fit in my alodine baths, it was a no brainer.  So, I drug out my alodine equipment and got to work on them.

Typical process:  Soak the skins in the Alumaprep33 for about 10 to 15 minutes.  I lightly scuffed mine while it was in the alumaprep.  Then I rinse off the alumaprep and dunk them into the alodine bath for about 15 minutes.  Then rinse off the alodine and let dry.  A pretty easy process, and during the waiting times, I reviewed my plans and double checked I was where I needed to be and that I hadn’t forgetten any other steps in the build.  The wing walk doublers came out looking pretty nice, with their golden hue.

The doubler on the right of that photo is in direct sunlight so it looks “washed” out, but its the same hue as the skin on the left in normal light.  These will be good to go! Then I cleaned up my mess and called it a night.  The next build session will probably be a priming session, where I’ll scuff, clean and shoor primer on these skins so it can cure a few days before dimpling.  Unless my pitot mast gets here before then!

Google Photos Link: https://photos.app.goo.gl/hHsqYXVEXgJLw1HP8

Hours Worked: 3.5

 

Attaching the Right Fuel Tank

I decided to get the right fuel tank attached to the right main spar tonight.  I did a little cleanup work on the fuel tank where the sealant squished out and was causing some interference with the splice plate and not letting it fit snug.  I used a phenolic scraper and lots of elbow grease to scrap away tiny amounts of sealant around the screw holes to leave clearance.  I forgot to start the timelapse at the first, but I remembered a little bit into the work session.  Here’s that video for what its worth:

Then I mounted the right fuel tank onto the right main spar and then started gently nudging it into place.  Removing the sealant helped a bunch!  I did need to use a pin punch to help jiggle the Z-brackets into alignment, they were ever so slightly out.  But this took very minimal effort and I threaded the bolts in with no problem. Heres the very most inboard bracket and bolts.  They are the only ones that mount from the FRONT of the main spar web, the others all go from the BACK of the main spar web.  You can see my pin punch helping hold things centered while I finger tigthened the screw in place, and then tightened it down with a wrench.

Now, I have no good way of getting these to the prescribed torque for an AN3 bolt because of the clearance, so I just have to go with what feels right.  Maybe its too tight?  Then I went ahead and threaded all the other bolts, including their washers, into all of the Z-brackets holes and just snugged them up for now.  I’m going to order a Tekton 1/4″ torque wrench, since I think I’ll be needing it a bunch.  It has lots of good reviews here:  https://amzn.to/2Gwjs6l

After that, I went ahead and screwed all the screws in place.  I dabbed a bit of Boelube on the threads of each screw to help it thread into the new nutplates, maybe it will also reduce corrosion too.  It made screwing these screws in pretty easy.  I also used a cordless screw driver to get them started, then came back and tightened them down with a proper hand screw driver to make sure they are good and tight.

The tank to leading edge joint looks really nice.  Except for one tiny spot at the very leading edge where there is a slight buge in the tank skin, or possibly a dip in the leading edge skin (maybe both?).  It’s not very bad, and I am not sure I could get it any better to be honest.  There isn’t any sealant under there causing it.  So, I will leave it as it is, and see if the paint shop can get it straight when they remove the tanks to do the final painting (after I fly off the phase I and II testing).  What do you think?  does it look bad?

After that, I did a little cleanup, and pondered a bit while looking at the skeletons of both wings.  Thinking about the pitot mast, wiring, conduit, etc and sort of planning for it all.  These things are starting to take shape, and its feeling pretty good.  I’d love to get the top skins riveted on soon so that I can get them into the cradle for the rest of the work.  Like most every other builder, the bottom skins will remain off until right before mounting to the fueselage, this way I can decide on autopilot servos etc.  I did get the top skins up on the bench and done some more scarfing on them.  I am not 100% happy with these scarf joints.  I think I may borrow my wifes sander and try some emory cloth on it to see how it does on knocking these down a bit.  Here is what they look like so far:

Thats it for tonight.  I’ll keep plugging on these top wing skins for both wings next.  I’ll probably deburr them, break the lap joints a bit, then get them ready for scuffing and priming. Then I’ll dimple them and start riveting them on!

Google Photos Link: https://photos.app.goo.gl/mnMDQFZWGgtfeCta7

Hours Worked:  1.75

Riveting the Right Leading Edge and Attaching to Skeleton

ALOT accomplished in this session.  I managed to get the right leading edge fully riveted, AND even got it attached to the right wing skeleton with some help from Tammy. This wing is ready for the fuel tank to be attached, and then on to the top skins.  I managed to capture the entire work session in a time lapse below:

I started by using my squeezer to squeeze the aft 3 ritvets on both the top and bottom of the leading edge.  This worked pretty easy, I wish I could have squeezed all of them!

The rest I bucked old school.  Not a lot to talk about here, but I did manage to get all of the ribs riveted on completely.  I did use caution and make sure I used the slightly longer rivets on the inboard rib where the splice plate goes to attach the fuel tanks.  Since we have another piece of metal in this sandwhich, we need a slightly longer rivet.

I did get a little creative with affixing the cradle to my work table to make riveting it a bit easier.  I wound up using my clamps to hold each other down while also holding the leading edge cradle:

This actually worked better than I thought it would!  After a little bit of work, I had all the rivets set in the leading edge ribs.  I also went back and inspected each one to make sure I had them all set corretcly and there was a handfull that I needed to buck a few more taps.  I’m happy with all of them now.

I grabbed a timelapse of me just working on the leading edge, which I will share below.  Its a bit of a closer view than my normal overhead.

After this, it was time to rivet the leading edge onto the right wing! I double checked the twist and sag on my main spar with a digital level, and the fishing line strung across the rivet holes.  Then I vacuumed all the shavings and dust from the skeleton to get it squeeky clean for final riveting.  Then I sat the leading edge down onto the wing and clecoed it in place.

I got my wife Tammy to come down and hold the bucking bar while I set the rivets that hold the aft flanges of the leading edge to the main spar web.  This made this work much easier and quicker than me trying to reach in and do it all myself, like it was on the left wing. Then she was free to go, as all I had left at this point was to rivet the skin to the main spar web, using a squeezer. Making sure that where the skin and ribs riveted together with the spar web I used the longer rivets for the extra thickness.  The time lapse below captured this work close up.

Now, my leading edge was riveted onto the wing!  The next thing I did was to insert the rivets that hold the very forward section of the ribs to the main spar web, underneath the tank skins.  These were AN426AD4-5 rivets, and I used the squeezer to set them.

Then I sat the tank on the leading edge to see how things fit, and I noticed I’ll need to clear some sealant around the skin where it bolts to the splice plate on the leading edge.  I let this goop out a bit to far.  No biggie, I’ll use a phenolic scraper to scrape just enough back to get the clearance I need.  But, that gets the right wing in a good spot, and at the same progress as the left wing.  I’ll need to scuff and prime the wing skins, then dimple them. Then I can proceed with the rest of the work. We’re getting close to being done on these wings!

And thats a good stopping point for today.  LOTS of work in this session, and I feel like I got a bunch accomplished.  I think I will change gears and deburr, scuff and prime the top wing skins so they’ll be ready to dimple and then rivet on.  I have ordered my pitot mast mount from Stein Air, and I decided to go with a Gretz Mount.  I’ll do a session just installing the pitot mast as soon as it gets here, so I’ll leave the top skin off the left wing until then.  This is where the build starts to get fun!

Google Photos Link:

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Hours Worked: 4.0

Countersinking the Right Wing Skeleton

Another quick build session. I managed to get the entire right wing skeleton machine countersunk. Pretty simple work, I did have to match drill a few holes I missed somehow, but no biggie.


I also sprayed some rattle can primer on the newly countersunk holes.


Hours worked: 1.5