Project 5 build thread

[alexM]

Tonight I ran the cables for the left side.

I should say "I made a meat hook on the end of a cable, and then decided to stop and use the super glue trick". Then I routed the cables. Got the pulleys backwards the first time (the cables cross and touch), then it all came together.

I got all the hardware sorted then set up some good light and attached the cable ends to the ruddee pedal torque tubes. Still need to torque and install cotter pins obviously.
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[alexM]

The other night I got the right side cables slipped into place and routed to the tail cone where they splice to the left side. I noticed that (in the series 5, anyway) it looked like the swaged fittings would rub on the diagonal fuselage tube and considered staggering them to avoid contact.
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I read through various forum posts here and found I'm not the first to ask, and that it's nothing to worry about once the cables are properly set. It would also likely result in the Nicopress fittings hitting the guide tubes before reaching full travel and that would be bad. And yes, I'll be adding some heat shrink over those splices.
You can see that in spite of my crazy questions in another thread regarding use of Spectra for Kevlar for rudder cables I'm going with the 7x19 1/8" SS cables that were in my box.

I've also read through the builders tips and read the posts regarding setting up the cables and I no longer fear getting them uneven or needing turnbuckles to make up for my errors. This forum is such a great resource.

Anyway, I can't complete the cable length setting until I've worked out the exact rudder location. Since my rudder was completed by builder #1 I need it in place so I can install my vertical fin ribs to align with them, install the fairing at the aft edge of the vertical fin and then fine tune where my rudder hangs. It is probably exactly where it is going to live, but un-cutting cable is a skill I don't have.

That means I need to stop with the cables and start with the ribs, so I spent the end of my build session doing the initial fitting of those. You'll see that I obtained fresh ribs from Kitfox which would be installed if this were a series 7.
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These all went well enough and sit relaxed in position. I have two questions for the gallery before I close this post out. See below:
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The manual for the series 5 has you take a significant chunk out and bond it back in, but that is because there were no lightening holes. The series 7 manual says you remove a chunk, but the image shows a kerf cut which seems to imply I'll be able to flex and wiggle the rib in place over that narrow tube. Is that going to work, or do I need to remove a wider section? I'm quite sure I can figure it out but the next one has be more stumped.
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The last rib in my pile would appear to be the bottom one, but mine is in one piece and it looks like I'll have to cut it into two. I vaguely recall seeing this somewhere but my renewed search comes up empty, and my RTFM session in both the series 5 and series 7 books don't say a word about cutting this rib. I've got an approximate dimension figured out where to cut between the two holes, just looking for a sanity check before I proceed.

[Eric Page]

I have two questions for the gallery before I close this post out. [...]

The manual for the series 5 has you take a significant chunk out and bond it back in, but that is because there were no lightening holes. The series 7 manual says you remove a chunk, but the image shows a kerf cut which seems to imply I'll be able to flex and wiggle the rib in place over that narrow tube. Is that going to work, or do I need to remove a wider section? I'm quite sure I can figure it out but the next one has be more stumped.

The last rib in my pile would appear to be the bottom one, but mine is in one piece and it looks like I'll have to cut it into two. I vaguely recall seeing this somewhere but my renewed search comes up empty, and my RTFM session in both the series 5 and series 7 books don't say a word about cutting this rib. I've got an approximate dimension figured out where to cut between the two holes, just looking for a sanity check before I proceed.

Alex, here are a couple of photos of my fuselage that might help (ignore the shoddy adhesive application by builder #1). I suspect the lower rib you recall seeing was on my build.

I've exchanged a few emails with Debra McBean recently, preparing a parts order, and that bottom rib is one of the items I'll need to replace when I get the welding done. She had this to say about that rib: "That bottom rib is cut by the builder in half to fit into the Vert Stab."

[alexM]

Alex, here are a couple of photos of my fuselage that might help (ignore the shoddy adhesive application by builder #1). I suspect the lower rib you recall seeing was on my build.

I've exchanged a few emails with Debra McBean recently, preparing a parts order, and that bottom rib is one of the items I'll need to replace when I get the welding done. She had this to say about that rib: "That bottom rib is cut by the builder in half to fit into the Vert Stab."

Thanks Eric,
I cut that bottom rib last night and I made a single angled cut on my vertical fin rib and it slips perfectly over the diagonal brace tube.
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Now that everything is "dry fit" I will remove them all and sand them with 220 per the manual, then work out my bonding strategy.

[alexM]

It has been a productive weekend so far. I've managed to get something done almost every night this past week, starting with sanding all of the wood pieces. Thursday night is when it got serious. I recently sprung for yet another Milwaukee tool, a Random Orbit Sander, and had to try it out. The book calls for 220 and the sander made quick work of it. Super smooth parts in no time.
I cleaned the parts and used the super glue trick to minimally tack the top 4-5 ribs in place making sure the alignment was as close to perfect as I could get. I clamped them in place and checked the orientation of the ribs relative to the temporarily hung rudder, then got on a step stool at the front of the plane and make sure there was no tilt I would regret later. I've built enough models to know that if you don't step back a ways and look you'll get some real forehead slapper errors glued in the ugly position.
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The next night I tacked the remaining wood pieces with the exception of the rib and bulkhead which get the aluminum angle for the tail access cover.
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More on those shortly because they were renting some space in my head.

On the same night that I super glued the lower ribs in place I mixed up 28 grams of structural adhesive and using my newly acquired horse syringe, my finger and several rags soaked with denatured alcohol I filleted the ribs from the previous night in place. That went well enough and I'm glad I used the super glue trick so I didn't have to worry about part placement as much. I still used several clamps and triple checked the alignment on every piece before I turned out the shop lights.

Last night I mostly stared at the parts. Regarding the ribs which get the aluminum pieces riveted/bonded to them, when I RTFM it says to bond the rib in place first. Later on I drill and attached the aluminum angle with adhesive and rivets. Then you bond the forward bulkhead, and then the aluminum piece.

The manual talks about how the rivets at the front may be hard to reach and to just do the best you can and count on adhesive for the rest. Uh, so more on that later on. It occurred to me that fitting and drilling those angles prior to bonding the rib in place might be a smart move. Not the riveting/bonding, because that would prevent you from being able to flex the rib in place. Just getting it all match drilled where it was easy - on the bench.

In order to fit those angles I would need to first fit the fairing which goes up the rudder post. That brings us to this morning, when I removed the rudder and spent a few hours fitting that fairing to the aft edge of the vertical stab and preparing it for bonding. After about ten tries I gradually shaped the tail edges of the vertical fin ribs until I could clamp the fairing at a single point and it would lay flat against the tail post with no preload or bridges. This included increasing the length of the "step" at the back of every fin rib where the fairing extended forward so it would lay absolutely flat when covered.
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With the fairing clamped in place I now knew exactly where the aluminum angle needed to start at the aft end.

Next I did my best job of reading the manual an interpreting how I should go about notching those aluminum angles. I cut the pieces longer than they needed to be and marked both of them symmetrically starting with 1.5" notches at the rear and transitioning to 1" and then .75" as I went forward. I marked them with a sharpie pen and then used the 2" cutoff wheel on my straight grinder. It's thickness is maybe 1/8" and once the cuts were made I realized I wouldn't need to cut V shaped notches after all. It was downright floppy with the cuts I made. I deburred the pieces and moved on.
Rib clamped in place, fairing clamped in place, I carefully marked the aft starting point of the angle and started in with the #30 drill and Cleco fasteners.
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Shown above is the left side about 80% drilled and clamped. I stopped for dinner and here I am writing this. I'm headed back out to complete this side and then move on to the right side. I'll then deburr everything and bond the rib in place and set the angles aside.

Once the rib is bonded in place, I'll Cleco the angles in place, work out the forward end and then do this exact same job on the bulkhead.

Before I get that far however, I'll be sweeping some structural adhesive on the lower ribs and bonding on the tail post fairing. I still need to add the short stiffening cross pieces on three ribs too.

[alexM]

Today I spent quite a bit of time fitting and drilling the right side aluminum piece, working to make sure both sides were symmetrical. Then I deburred the metal and sanded the wood again. It sure was nice being able to do the clamping and drilling on the bench instead of glued in place.
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I also fit the forward bulkhead but have not yet made the aluminum angles.

After the picture was taken I mixed up 40 grams of structural adhesive and bonded/filleted the longitudinal stiffeners, and bonded in that lower rib (without the aluminum of course). I guess I'm working in small batches of adhesive but I like to be able to stop after a while to clean up and double check alignment before things start to set up. I've probably got two more batches of adhesive to mix and spread
Today I didn't use the syringe and it was messier than I would like. I'll go back to using them for sure.

[alexM]

Stopping for a few pictures. I had hoped to have the vertical fin aft fairing bonded in place already but I wanted to get the lower fin ribs in the fuselage bonded in place first. The bottom one down by the tail wheel would be easy to get in crooked, especially if you don't get your face down there and look.
My forehead slapper moment was when I lifted the tail up on a stool and found that I could sit on my rolling stool and get to it easily. I ended up removing one of the wood pieces because it was crooked with my tacking it in place with superglue.

Going back to the syringe method was a huge thing. I also borrowed from another thread and used masking tape outside the fillet area to make clean up easy. Turns out the syringe worked so well that I didn't get anything on the tape. Once I had squeezed a bead everywhere I needed, I just came back with a Popsicle stick and alcohol rag (and finger) to make it all smooth.
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I've got a pile of the curved tip irrigating syringes coming soon so I don't have to keep breaking out the dried Hysol between batches. Mostly I want that longer tip so I can reach into tighter spaces.
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Whoever suggested owning a ton of these clamps, thank you. They get lots of use.
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Random image, a 20' view of my tiny "shop". It's starting to look like an airplane. I even have the side stringers cleco'd in place now.
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Wanting to keep the momentum up while waiting for the Hysol to kick off at the tail end, I moved to the end that eats. I laid out the hole pattern for the console sidewall fasteners and drilled them. Still need to debur but I had been sweating this for a while.

Another thing I did was fine tune the rudder pedals. When I did a test run of the step where you block them in place and parallel for cutting the rudder cables I noticed that the right side pedals were perfectly parallel to the torque tubes and perpendicular to the floor, but the pedals on the left side weren't so square.

The manual has you set the length of the master cylinders at exactly 7.25" (if I recall), which is fine but it doesn't account for manufacturing variation in the rudder pedal torque tubes or the pedals themselves. So I removed the top bolt and adjusted the length of the master cylinders until all four pedals are in perfect alignment when blocked in place for setting the cables.

[Eric Page]

Boy, I sure wish the adhesive in my plane looked like that! As you well know, my first builder applied it with a spatula taped to the end of a broom stick. I'm on-my-knees grateful that it'll all be covered up with fabric. I just wish the plane didn't have to carry around the extra weight for its whole life...

[Frontier Fox]

I found that “catheter” syringes 60 ml. Worked really well and are inexpensive. I bought a case and it lasted through most of my build.

[alexM]

I found that “catheter” syringes 60 ml. Worked really well and are inexpensive. I bought a case and it lasted through most of my build.

I should be thankful that I have no clue what a catheter syringe looks like. I guess since I've gone through the awkwardness of buying "horse syringes" in person (where I was quick to add "uh, I don't need the needles"), I should be getting used to it.

My 60cc irrigation syringes (ordered through amazon) and big box of tongue depressors showed up yesterday. The syringes are not curved tip like I expected, but straight with a taper and big enough hole I don't need to open them up with a drill bit. Way back in another thread I found reference to silicone lubricant on the plungers and some debate about whether that was common. So far EVERY syringe I have purchased has had some thin film of slippery lube on the plunger, so prior to first use I clean it off with denatured alcohol.

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Two nights ago I bonded on the fairing for the rudder post. I thought I had it clamped up perfectly but when I removed all the restraints yesterday I found a bit of a "wow" or pucker between two ribs in the third bay from the top, and also found that below the horizontal stab the ribs didn't sit perfectly flush with the notches in the ribs.
I think both of these conditions would be obvious after covering so I set about fixing them. I still had some of the old ribs that had been removed from the vertical fin so I cut one of them to make a brace that will bring that wow/pucker into perfect alignment. It is ready to go it but I still need to epoxy varnish the bare wood before the brace goes in.
For the ribs below the horizontal stab I cut the Hysol loose and cleaned them up so they will lay perfectly flat on the second try. I did not mix up any Hysol last night, but probably do that later this afternoon after I make up the short rib stiffeners that run crosswise to the longitudinal axis.

However
Eager to see how the rudder fit up against the newly re-installed fairing I decided to hang the rudder. The first time I did the task it must have taken two hours to get the top and bottom bolts in, and I must have dropped bolts inside the vertical fin 100 times. I have an idea cooking in my head for a tool (a chunk of my career has been aerospace tool design) to make the job easier. Last night I prototyped my concept by taking a piece of frog tape about 9" long and slicing it into thin strips. I put the thin strip up near the head of the bolt and brought the two ends together in a sloppy tail. Then, grabbing the taped part of the bolt with a pair of needle nose and sticking the tail to the needle nose, I installed the first bolt in seconds.

Thinking it must have been a fluke I did the second one. I lost grip of the bolt with the needle nose but the tail did its job and I didn't even have to bend over once to pick up a bolt. Under five relaxed minutes and the top and bottom were in place. Why frog tape? Well other than it being what was close at hand I have found that it's not very sticky and has almost zero strength - but certainly enough for this job. Once the bolt is safely in the hole you just pull the tail hard and the tape "fails", leaving you with a mostly installed bolt. No scratches from the needle nose and no tape residue.

With the rudder temporarily re-hung I got to see the gap between the rudder/vertical stab for the first time. I have no idea what the gap is supposed to be. I know that aerodynamically it should be as close to zero as possible, but I also know I have to account for the thickness of the fabric. I ended up extended the bottom hinge a couple of full turns and now have a tiny bit over 1/4" top-bottom at the center line of the aircraft, and can run full deflection side to side without any gaps getting smaller.

I made my semi-weekly Aircraft Spruce order including a fresh batch of epoxy varnish, fresh Super fill, some hardware and some sheet metal tools.