Evening All,
Thanks Bob, Frank and Richie for your very generous comments - I really appreciate them.
I seem to be breaking new ground for me with this build, among which is two posts in as many days!
I have finally bitten the bullet in that I have soldered the lower wing spars to the nacelle frame. This is one of the most tricky parts of the assembly - if this is not completely accurate then the rest of the model will look distorted and unbalanced. In brief the spars have to be laterally dead centre to the nacelle, the centres of the spars have to be perpendicular to the sides of the nacelle, and the spars have to be at 90 degrees to the fore - aft line. Usually with wings there is a tab or interface between the end of the wing and the side of the nacelle which provide surfaces to join the wings to nacelle/fuselage, but in this case the spars are fixed to four points at the bottom and rear of the nacelle: if any of those are mis-aligned it can have unfortunate, not to write disastrous, consequences.
Before I soldered the spars I had to solder a piece of brass rod to the upper nose - this represents the upper part of the frame in front of the observer - a machine gun mount and a folding split windscreen was fixed to this on the real aircraft:
With this in place I proceeded to mount the spars. I put a rib on the ends of the spars to ensure that they were the correct distance apart and they could not move together or apart. I had carefully measured and marked the centres of both spars and these were lined fore-aft up as accurately as possible. The spars were placed on the bottom of the 4 vertical frames at the rear of the nacelle and the height of tips of the spars to the top of my desk measured - these had to be equidistant or the spars would not be properly aligned with the nacelle and one wing would be higher at the tip than the other. Minor adjustments were made until this was right. The the set-up was jigged so that the centres of the spars were in the centre of the nacelle frame, and that the spars could not move sideways or fore-aft while I wielded the soldering iron:
Having taken several deep breaths I proceed to solder and hoped that nothing moved while I was working. The result:
I have now got to write the instructions for the next stages of construction because I need to prime and paint the metalwork of the nacelle but do not want to prime the spars until later. This is because the ribs slide along the spars and strip the primer from the metal but I have to attach a rib flush to each side of the nacelle and these and the nacelle frame have to be painted first, and have holes for double lift wires drilled into them. I also need to consider carefully how and what to assemble inside the nacelle before I work on the wing ribs - which incidentally also have to have bracing wires. I intend to use my previous experience with the Gunbus, but some things are very different on this model and have not been fully worked out yet. However I am hoping that the next post will be a bit quicker than the current ones.
Thanks for looking.
Stephen.