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.
Tuesday was the day everything came together and I my aircraft was fully assembled. Previously in the week Peter & John balanced my plane to determine how much weight was required. The aircraft was quite tail heavy. Need to remember that as you move away from the center of gravity (CG) the effect of 1lb of weight is compounded. This means that even though the engine, wing, battery, etc. is all up at the front of the plane the tail still wanted to ‘sink’.
In order to counteract this John & Peter determined how much weight was required to place up in the nose so that the aircraft is actually a little nose heavy. They determined the weight required and already had the one side of the piece of metal sanded and a piece cut out for the drain hose from the engine to go through allowing the fuel to exit instead of pooling on the bottom. I then drilled two holes into the piece of metal.
It was great to get back working on my plane again. The time flew by as I think this was the longest I have worked in one session in a long time at about 2.5hrs.
During this time I finished covering one side of the fuselage. From the pilots perspective this was the front left side, as seen in the featured image at the top. Due to all the curves you have to deal with when covering this area it is a slow and detailed oriented process.
It starts first measuring out the piece of covering with some excess all around. Then you line it up to where you want it, about a quarter inch overlay with the back piece. I then tacked it down in a few places starting top middle and worked my way along the top edge, pulling tight to do some on the side and looking through the covering you can see where the outline for the wing to sit in resides to tack some along there as well.
Tuesday was another 2hr building session, which is about my typical. When you look at what I got done to the uninitiated you may think to yourself “It took you that long to do what?”. In order to install the rudder and elevator push rods correctly it takes time.
The first step is to figure out where the control horns need to be attached to the control surface (rudder & elevator). This is done by using a combination of the plans, to get a general idea where the horn needs to go as it’ll show where the support for it resides, and attaching the push rod to the servo to see where it lines up. The second allows you to determine the angle at which the control horn needs to be fastened to line up with the end of the push rod. As seen in the picture at the top I already have a hook in the push rod, which is attached to the servo arm.
Ensure that when you are installing the control horn and push rod the servo and control surface is in the neutral position.
Once this is determined you drill two holes through the control surface to act as the guides for the screws using a hand push drill, not electric, with a tiny bit. In my case it is two holes kitty corner to each other on the base of the control horn for fastening. When drilling you need to ensure you are going perpendicular to the surface and straight through, not at an angle, so take your time as it will pay off! I made this mistake and didn’t get it right so when placing the screws the opening on the back wasn’t lining up with the holes in the back plate causing issues. Thank-you John for the help correcting this and getting me on the straight and narrow for the elevator!
Last Tuesday I got to work on my plane again and been so busy since I’m only now getting around to blogging about it.
The first thing we did was install the wire for the tail wheel. This involved first bending the tip of the wire into a 90 degree angle and ‘sanding’ the wire to rough it up a bit which allows the glue to stick better to hold the wire into place. Then needed to drill a hole into the button of the rudder for where the end of the wire (the part bent up at an angle) will slide into. This provides a sturdier fit into the rudder, since this wire steers the tail through the wheel/rudder connection.
The remaining part of the wire that goes along the bottom of the rudder needs to be recessed into the rudder itself so that it is flush. In order to accomplish this I first lined up the wire and traced two guide lines along the bottom. Using the guide lines I drilled tiny wholes along its length to carve out a groove. I then alternated between using a drill bit to run along its length a tiny file to sand out the inside. I alternated and repeated until upon one of my checks the wire sat down into the rudder to my satisfaction. Note that we used the plans to figure out how far back the wire needed to go and also need to ensure that not to much sticks out at the leading edge that would interfere with rudder movement.
Once that was done and glued into place we then cut a piece out of a fiberglass sheet such that it would wrap around about 2 inches on each side. I then brushed glue over the fiber glass, ensuring to role any air pockets out of the fiberglass over the wire and down the sides. Once this was done it was left to dry.
The fiberglass provides additional support / reinforcement to the tail wheel assembly.
Next I went back to working on the wing and installed the invasion stripes on the bottom of each wing panel, seen in the feature picture at the top. Placing covering over top of covering can lead to an excessive amount of air bubbles forming as air gets trapped between the two layers. In order to help mitigate this issue I used the Top Flite Woodpecker Perforating Tool:
Saturday I got over to Peter’s for another building session. We started by going over what Peter had done. In order to not ‘waste’ my time on some of the easy but tedious stuff Peter will do some of it for me when he has a chance so that those things don’t hold us up in the project. He then goes over how he did it so that I still gain some exposure to the task.
One of those things was attaching the hatch covers to the bottom of the wing, seen at the top and bottom of this post, and the other was running the leads from the servos out the two wholes in the top of the wing. He used the previously run string to pull the wires through, since covering is now applied. By tying the string around one end of the wire (ensuring you go along the connector and between two of the wires so the string doesn’t slip off while being pulled). You then slowly pull the string through, working the string and lead back and forth if it catches, until you are up and through the hole. Repeat for the other servo.
You can then connect the leads to a receiver to test the servos with your transmitter.
Hinges are used to connect control surfaces (i.e. ailerons, rudder, elevator) to a main part of the aircraft (i.e wing, fin, stabilizer). How I learned to do this is as follows and I will be using the context of installing the ailerons.
First I use a motorized hinge slotting tool (i.e. Great Planes Slot Machine, Fig. 1) to make the hinge slots into the trailing edge of the plane and ailerons. This was done, and matched up, prior to covering. Then once covered you can use the back of a scalpel to gently poke around about where the hinge slots should be. Once you’ve poked through and found the slot you cut along its length exposing the slot.
Tuesday I was able to get in some more covering and visiting. I started by covering the ailerons, which as you can see from the pic above I did in green. Kevin stopped by for a visit to see how things were going and a bit of a chat. It is nice to see guys interested in what’s going on and my progress, even if it is a bit nerve racking at times but we all need to start somewhere, lol.
I also covered the servo hatch covers, seen below. Which was done the same colour as the bottom of the wing so that they match and blends into the rest of the wing.
In order to more easily cover the hatch covers I detached the servos. The overall covering was pretty straight forward though a little awkward due to the small surface area. John taught me the proper way to cut the covering away from the opening where the servo arm goes through. Because you want to have covering over the edges of the opening to protect the wood you cut down the centre of the opening (length wise) and then two cuts into the ‘corners’ of the rounded ends. From there you fold the covering pieces over and iron it down to the edge and back side of the cover.
An ‘oopsie’ was discovered in this process where one of the blocks wasn’t glued to the hatch cover and thus fell off. Good thing this was discovered now, by John, so it could be glued and clamped so that it is properly attached.
Saturday was another great building session. John stopped by for a visit to check out how things were coming along and contrary to the ‘hack’ job he voices I believe he thinks I’m doing a pretty decent job :).
Thanks to Peter for trimming off the excess of the top left covering I didn’t have a chance to finish last time as well as along the leading edge and sealing that down. Both Peter & I learned something new yesterday from John, which is how to cut a pretty straight/clean edge. After covering the top of the left panel, sealed all around the edges and using the blow drier to shrink of the center need to fold some over the leading edge to prevent wind from getting under and peeling it off.
Once adhered the time came for the trim trick demonstrated by John. Depending on where you want the line you allow the side of the blade to rest against the ‘natural’ curve at the desired angle and follow it along the length of the wing while you are making your cut. Ideally you want to do the entire cut from the same position as changing position can alter the cut reducing the visual straightness (for lack of a better word) of the line. This also ensure that it is cut to the same length throughout. Once cut you then use the iron to roll over the top of the leading edge onto what remains after the cut to adhere to to the wing.
The last part was cutting a piece for the center of the wing. Had to mark the wholes for the dowels, which I then cut out, and once fitting the covering over with the dowels through marked the two square wholes where the cables will come out. I then applied the covering to the sheeting on the wing keeping the iron level (sides to the bottom/top) and working from the center out to the left, followed by center out to the right and vise versa. Always want to start in the center so you work any air bubbles, wrinkles or other imperfections out to the edge in hopes they disappear :). Once done I found the two square holes, generally marked via the string previously pulled through the marking wholes. I made sure the covering was adhered firmly around the edge prior to cutting out the covering to expose the holes. We still have the string coming out, don’t want to loose it, as the string will act as our guide when running the wires for the servo in each wing panel.
I did my best to line up the bottom edge of the L panel yellow covering to look similar to the R as well as the center to be lined up with the L & R wing panel.
To wind up the evening you can see I started covering the ailerons, just the tips so far, which will be done fully in green. Before starting that next time I am going to go over the wing to make sure it’s done as best I can get it.
The aircraft is really starting to come together and will be starting to cover the tail soon and working on the fuselage. As a fun aside I need to find my pilot, which can be about 2-2.5″ tall with a fairly wide base as will want to glue and screw into place.
Saturday was the first building session of the new year after Christmas holidays. John stopped by and showed me more about covering. He also brought his woodpecker over which is a device used for making tiny wholes in the surface when you are covering. In my case I used it when covering the wood sheeting where the wings connect. You can also use it when putting covering over top of covering.
The idea behind the woodpecker is that the tiny wholes it makes allows for air to escape instead of getting trapped between the covering you are applying and the surface you are covering which would create air bubbles and creases that can be a royal pain to get out.
This session I covered the entire bottom of the wing using safety orange. Peter and John weren’t kidding when they stated that covering takes a long time in order to do it right and get a decent look. One definitely needs to strike a balance between perfect and good enough or else you’ll never get done! Lol.
With covering the bottom (and eventually I will do similar for the top) of the wing I did it in 3 pieces. The left wing, right wing and centre piece. Once measured and cut I started by pinning into place and ironing down parts of the edges to adhere some of the covering initially. I then worked on ironing the rest of the perimeter starting in the middle and working my way to the outside alternating between the top edge and the bottom edge. The bottom or trailing edge piece overlaps the green I did for the trailing edge and you need to make sure not to overheat it or else you risk the underlying covering (green) coming off.
Once I got the edges done (as well as what overlaps onto the centre sheeting) you use a ‘special’ blow dryer to heat up the covering. You need to ensure you keep the blow dryer at a safe distance from the covering (approx. 3″ I believe) and constantly moving or else you risk burning a whole through the covering. Then you need to start all over again.
Felt good to be back working on the plane and I’m looking forward to tonight’s session as well.
Tuesday was all about covering and a special visitor. Stephanie stopped by to check out what I’ve been up to. Even though she has been seeing the pictures/posts along the way I believe she gained a better appreciation of what’s involved and how the plane looks (especially the size of the aircraft). Stephanie also helped me decide on the color scheme. Settled on going orange on the bottom and yellow on top. This will follow for the whole plane.
After checking out what I’ve been working on Steph and Peter headed upstairs to chat with while I was left to my own devices. This evening I got the rest of the trailing edge covered (top & bottom, pic at the top and bottom respectively). Covering is slow and steady work.
Steph came and checked my progress before leaving and later John stopped by to check things out as well as drop off some hardware.
Once I finished covering the trailing edge we had a gab session before I headed out. This post is short and sweet and will be the last one until the new year.