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.
Tuesday I was able to work on my plane for a couple hours.
Prior to covering the top of the wing I needed to cut the covering that was over the servo hatches. After cutting the covering into an ‘X’, corner to corner, I turned the wing back around and ensured that the covering is firmly adhered around the opening. I then folded the cut pieces over, one per side, and performing little cuts where necessary to get the desired fold. Then using a tiny iron I adhered the covering to the side of the wood before flipping over and adhering the leftovers to the inside wood (provides better attachment then cutting the excess short) and then only trimming where little bits stuck up higher than the ‘height’ of the wing so as not to affect when covering the top.
This can be seen in the image below:
Once that was done I covered the top of one half of the wing (seen in the featured image at the top). I ran out of time as I was getting tired and hungry so I will have to perform the finishing touches next time prior to starting the other wing panel. The touch ups include making sure there are no sagging parts, trimming the excess along the edges, etc.
As a note, this time prior to even starting to cover the top I used the woodpecker over the entire exposed sheeting where the two wing panels are connected.
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.