Evening All
Thanks Dave for dropping by - you comment is much appreciated.
One of the minor problems which resulted from moulding the fuselage was the rounded corners on the lower sides. These corners should be square. To remedy this deficiency is simple: I glued some stretched sprue around the edges which need to be squared off. When this was dry I applied a liberal coat of plastic putty over the sprue, waited for that to set and then sanded the corners until they were square:
I learned this from another modeller who makes vacuforms where the same problem frequently arises.
The lower wings were cemented to the nacelle one at a time. The first was attached, supported with a sophisticated jig, and allowed to set overnight:
Next day I repeated the process with the other lower wing.
With the wings in place and any small imperfections filled I was ready to fix the booms to the lower and upper wings. I have made many pushers and developed a simple technique which requires the same level of sophistication of jig manufacture as that required to fix the lower wings in place. First I use the side elevation to draw a line under the wing which touches the leading and trailing edges and continues to the rear beyond the leading edge of the horizontal stabilizer. Now measure the vertical distance on the plan from the new line to the leading edge of the rear horizontal stabilizer (distance a).
I use florists wire for the booms on my True Scale models and attach it to the wings by using the end of a round file to make a groove in the top or bottom surface of the rear of the wing. To locate where to file the groove, I place the nacelle and lower wing, or top wing, over the plans and trace the line of the booms on to the rear surfaces of the relevant wings. I measure how far forward the booms fit on to the wing - that marks the forward and deepest point of the groove. The florists wire is placed on the plans and four suitable lengths cut, two for each wing. (I know that this method is not 100% accurate but it is close enough in this scale that it does not matter if a boom is a couple of mm too long or short). The front ends of the booms are filed to make them flatter and thinner to achieve a larger surface in contact with the wing and allow the boom to taper forwards. The rear ends of the booms are filed to make a neat V when viewed from above and make a better mating surface.
Now make the jig. First lay the nacelle and wings over a copy of the plans so that the wings align with the plans exactly and lie flat on the bench. Take some scrap plastic/wood/card and make a support which is the same thickness as the vertical height (a) and place it so that the leading edge sits directly over the leading edge of the horizontal stabilizer on the plan. I use two part epoxy to attach the booms to the wings as this gives me a bit of wriggle time. When I am happy that the booms are properly set and aligned on the wing and are resting on the rear support I apply a small drop of CA to the V joint at the rear. This helps to stabilize the structure while the epoxy cures overnight.
Repeat the above operation with the top wing.
The booms should now be at the correct angle in relation to the wings. The upper and lower parts of the aeroplane are now ready for painting.
I have made the wheels using another simple process. Cut the wheel discs from circles of 60 thou card: I cut out squares, trim the corners and finish with a file. I also file down the edges until they are about half the thickness of the card. Take a length of 60 thou rod, wind it around a paintbrush handle which is a slightly smaller diameter that the wheel discs, and immerse for a few seconds in boiling water. Remove from the water and plunge into cold water to set the plastic and leave a spiral. Cut off a length from the spiral which is slightly too long to fit over the disc, pull the ends of the cut plastic together to make them meet properly and place over the disc. By careful trimming of the end of the plastic rod a tyre can be cut which will sit tightly on the wheel disc. Hold in place with liquid cement and when dry clean up with filler and glass paper as necessary:
I know that in the above image I have a tyre from red rod and a spiral from white: I used the last of an old spiral to make the first tyre.
Thanks for looking.
Stephen.
