Though my plane according to the plans was complete, Monday I truly completed my aircraft!
Outside of the plans, based on club members experience, I added support wires to the tail. You can see them installed in the featured image above. The reason for this addition is that a known flaw in the design of the aircraft is the weakness of the fin. If you were just flying in circles and figure eights you would be just fine but as soon as you started performing loops and rolls you would have a problem.
That problem is that the forces applied to the fin during these maneuvers would cause the tail to twist making the aircraft unstable in the air. This instability, and perhaps damage, leads to a lack of control and I believe even the potential for the fin to break.
The wires were created by John based on the ones installed on his 4 Star 60. He sautered the ends to bolt to the surfaces onto the wire. The are adjustable for length as you want to make sure they are at about the middle of the top of the fin as well as the middle of the outer edge of the stabiliser into solid wood, but not to close to the edge to ensure a firm hold.
Doing one at a time you line it up and mark where the holes need to go into the stab and the fin. Adjustments needed to be made on the ends to ensure they sit flush with the surface of the aircraft. You then drill out the holes, ensuring you go through in a straight line as you don’t want to be at an angle. Next you put the screws through (screw it in once required) and then put a locking nut on the screw through the stab. Can leave the one through the fin for now.
Had a great building session with Peter last night making further progress on the wing and started the covering process.
In the picture above you can see how Peter cleaned up the sheeting so everything looks nice and smooth giving a better/easier finish. When gluing the fillers he mixed a special substance in with the glue that makes the glue easier to sand . I then marked and cut out the two wholes you see. This is where the wires for the servos in the wing come up through, connect to a y-harness and then connect that to the receiver; which, will be contained within the fuselage.
Once that was done we flipped the wing. Priot to sheeting the bottom we ran a piece of string through the tubes from the servo box up through the whole to allow us to run the wires when the time comes. Then going through a similar process as when we sheeted the top I measured out and sanded the two pieces you see pinned in the pic below. Once I got the desired fit I glued them into place.
Here’s where we did something a little different. You’ll notice the leading edge piece that needs to be shaped isn’t installed. Due to the fight we had with it last time we decided to soak it in warm water and then mould the piece around the wing at the end, held in place with elastics near the ribs for support, and let it dry so that the sheet is closely formed to what is required upon install. Once the sheet dries we should be able to more accurately figure out where the slots need to be cut and glue it into place with, hopefully, greater ease.
To end the day I learned the basics of covering. When covering surfaces (i.e. elevators & stabilizer seen below) it is best to do all the edges first and then take a break. The theory being you are taking the same actions with the iron in all cases instead of switching between edges and sheeting the main surface, which will come next.
I decided to do my control surfaces (minus rudder) in green so you can see the edges of my elevators completed. When covering you need to heat it up in the centre first and then work your way out to ensure you don’t get any bubbles. Then when going over the edge ensure you start flat on the top, roll over until the iron is flat on the side and then pull down. When rounding at the corners need to cut the covering in a straight line along the angle(s) to the ‘curve’ / change in direction of the wood surface.
I also did the back edge of the stabilizer, which in my design is orange.
In the picture below you can already start to see what the final look is going to be like with the contrast between the orange stabilizer and green elevator. This will be most noticeable on the ground as in the air green turns to black.
Yesterday we had a productive 2 hr building session. I love seeing my project slowly come together and take on more and more of a ‘total plane’ look/shape.
The evening started with checking out the ‘rig’ Peter created for drilling the holes for the dowels into the dowel support blocks. Because every planes wing is different you need to create this for each one! you can see the hole setup in the pic at the top of the post. The devices gripping the wings and actually slotted to hold the edges is set to ensure that the wing maintains the correct angle (if the angle is wrong the dowel holes will be off). These dowels are what will slip into the fuselage to hold the front of the wing while the back will be bolted on. Pinned to the front is the template for where the holes need to be made in order to match up properly with the fuselage. Then placing the drill bit into the device guiding it straight drilled into the support blocks providing a guide hole.
Here I went off plans and based on more experienced builders in the club. I’m going to place a hatch cover to provide easier access to the fuel tank. In order to do this need to reinforce T1 to provide support and a place for my hatch cover to screw into. I took a rectangular piece of scrap balsa wood and then figured out what width it needed to be, cut it and then traced the arch of the T1 piece followed by cutting it out and then sanding to get close to the same shape as T1. I didn’t want to sand perfect as will finish sanding once the glue dries so it is the same shape as T1.
I cut the hole for the switch for turning the plane on/off. For this I had to measure on the inside to see where I wanted the switch to be (between the edges of the doubler slot, to thick to go through the doubler as well) and then translate it to the outside where I did the work. I used the one piece as a stencil to mark the shape with a pencil. I did my best to make sure the hole was level so the switch won’t look all cockeyed once installed.
Then using a tiny drill bit I drilled a little hole in the four corners before going up to a bigger drill bit and drilling within the pencil lines to start opening up the hole. After that Peter used a tool to remove more followed by me finishing it off by sanding (not with sand paper! lol). You can see the switch placed in the slot in the pic below. Will need to remove for covering.
The last task of the evening was getting the stabilizer attached to the fuselage. First marked the center of the tail (where the stabilizer will sit) followed by centering the stabilizer on the back of the fuselage and penciled the lines to mark where glue needed to be applied. Then taped both the sides of the fuselage and next to the pencil marks on the stabilizer to ensure no excess glue gets stuck to those surfaces that will be covered.
Once that was done place glue on the stablizer and then set it on the fuselage, centered it both front and back using the pencil marks on the back and the center of the one ‘stick’ of wood for centering the front. We then clamped into place (used a block of wood so not right on the stabilizer) and once happy placed weight to hold in place.
This concluded another building session and next time I should be able to get a nice picture to really show the plane taking shape!
Today was another great day of building. I lucked out today with some extra assistance to keep things moving along. John cut the find down to size and sanded the edges for me. Even sanded the sheeting. Apparently this is one of the reasons why we don’t use the 1/16th that comes with as wouldn’t be able to sand. We don’t do all the final touches on anything until ready to install due to hangar rash, that is the potential for bumps and what not while around the workshop. We’ll want to make sure that sheeting surfaces are sanded smooth, excess glue gone, etc. Before applying the covering to prevent wrinkles, bumps etc. in the covering.
I marked the centre on the trailing edge followed by where the hinges have to go using the plans. After practicing with scrap wood I made the slots for the hinges. The other thing I had to do was start rounding the leading edge for aerodynamics. This involved again first marking the centre, marking with a pencil so far from the edge on both sides as to how far to sand for starting the rounding, and then sanding the side edges at a 45 degree angle up to the line to get the rounding effect.
I repeated this process for the stabilizer as well, using the plans to mark where the hinges had to go, the centre position, and making the slots for the hinges. Here I started rounding the leading edges using the same technique.
Peter showed me with the fin how to use sandpaper to finish the rounding effect using a finger on each side to apply pressure while moving the sand paper left to right over the edge as well as up and down the length of the edge focusing on one side or the other as needed to even it out. You use the marked centre line as your guide since without it you’d have a hard time knowing what was the centre once you’ve started sanding.
On the stabilizer I marked the centre lines on all three sides (not the flat top as no hinge goes here and it won’t be rounded, actually want it to be flat and level for connecting to the body of the plane later). Where you see the pencil marks that is the centre of my hinges, 6 total – 3 per half. These markings with the long line is to help find hinge placements once covering is applied first to the edge so we can cut out the hinge location before covering the rest and putting the hinge in (dido for the fin).
Here’s a closeup of the edge where two hinges are marked and cut. The cut into the wood for the hinge is very hard to notice which is where the markers are very helpful.
To continue prepping the fuselage today I glued the fuselage doublers to the corresponding fuselage side as we labeled yesterday. We first traced them to guide us where we need to place it and to know where we can’t allow excess glue to remain. I used a different kind of glue, titebond wood glue, for this as slower to set so absorbs in and creates a stronger bond. As I glued each one we weighted it down to hold it in place and ensure contact is maintained throughout the drying process. We had to ensure we wiped away excess glue from the slots and other areas where future pierces will go.
Another big thanks to John and Peter for the work they did on the firewall starting with marking the centre and where the engine lies on the firewall. Peter explained to me how they used Johns Saito 100 4 stroke engine (same engine I’ll be buying for mine) to mark out where the holes have to go to on the engine mounts (they already drilled them for me) and made the small wholes where they’ll be attached to the firewall. They also already had the whole drilled for where the fuel lines will pass through the firewall to the tank. Today I drilled out the 4 tiny wholes to their proper size, 1/16th I believe it was and special tool was used to determine the size of bit required. I then placed Vaseline into the blind nuts to prevent glue from getting in as glue was applied around the four holes and then the nuts were pushed into place.
The last thing I did for the day was glue the tail wheel mount to the back of the fuselage bottom plate. You can see the round weight over the top holding it down at the right of the pic with the weighted down glued doublers.
This morning I was up early, odd for a weekend, and off to Peters for what turned out to be a 2.5hr building session which flew by! No pun intended, lol.
Forgot to take a picture of this step but I glued the sheeting to the fin I built and prepped last day and basically looks the same as the sheeting pic but just one of them. Peter did finish off the fin after the glue dried by gluing the trailing edge for me so we were ready for sheeting today, thank you. While John was tracing out the fuselage pieces to make templates, as he needs to build one from scratch, I worked one the stabilizer.
Since the glue had dried for the stabilizer I pinned through the sheeting approximately an inch from the frame edges and then used a ruler and pencil to make guide lines for cutting the bulk of the excess off with the bandsaw. For some of the angles had to get creative and learn that I don’t have to cut along the line the first time but can cut further away and work my way in.
Once I had the general outline cut out I used an exacto knife to cut away more of the excess getting me relatively close. Using a hand sander I sanded away what was left of the sheeting overhanging the edges of the framework, making a heck of a mess! John kindly demonstrated how to more efficiently sand as it was looking like I was going to be their for days!
While sanding have to make sure the top and bottom ‘overhang’ are getting sanded by just sanding one at a time when necessary and/or angling the sander appropriately to not over sand parts. Once smooth with the framework edges and the burning from the laser cut pretty much gone you’re done. I ended up with the following and will have to round the leading edges later:
To wrap up the session I started assembling the fuselage by gluing the fuselage front to its side. Before any gluing took place we spent a good chunk of time eyeing the pieces and the plans to see how everything was going together, including what will likely need to be glued next which is the doublers pictured above (their are 2 stacked on top of each other) and how they’ll fit on the inside of the fuselage side. Good thing we double and tripple checked as we had the top and bottom of the fuselage side mixed up! We also made sure we understood where excess spacing was allowed for the top and bottom plates to fit along with other pieces.
Once we had it all figured out as to how the sides will come up, doublers eventually fit in, and front pieces fit in I sanded where the front fuselage joins the side fuselage pieces, glued and placed them together followed by placing weights over wax paper to keep everything in place to dry as seen below.
That concluded another day of building and planning to get in another session tomorrow! I’m still really enjoying building; however, if I was to make an adjustment for next time it would be to wear some sort of face mask when doing large quantities of sanding (i.e. as I mentioned for the stabilizer above). Peter mentioned their won’t be much more sanding left now.