Progress has slowed in the build up to Christmas, however I have managed to do some work.
Time for some struttery!
I had sourced some 1/48 scale line drawings of the F4B some time ago (unfortunately I can't recall where I got them – intraweb somewhere, but they are tagged with the drafter name – N. Okolelov). The F4B-3 is reasonably close to the P-12E, especially in terms of general layout of wings, struts and tailplanes, so I used this (and the F4B-4) as a basis to determine what the actual outboard strut length should be. I initially had a concern that I would not be able to determine what the true length of the strut would be, but after establishing the centre post is basically vertical, it is then easy to use the front view as an accurate representation of it's true length.
The cabane struts were easier in establishing that the front view should be the true length, but the line drawing does not give a fuselage profile at the point the strut mounts from the fuselage and is therefore a series of trial and error to get it correct.
Now having some dimensions to work with I set about creating a template to assist in aligning the struts once I started to put them into place. Like I had done before for a biplane build a while back, I used clear acetate from some packaging and set out the centre points for locating the struts. To keep the acetate straight, I CA glued a length of sprue as you can see on the photo below. This allowed me to set about fitting both sets of struts.
You can also see my high-tech solution to hold bits in place as I jiggle parts into alignment – blu-tack! Very handy when you need three or four hands.
As the struts (unhelpfully…) have no locating pins and are just butt joins to the wings, I decided some brass pins would be the best solution. Once these were fabricated and the locating holes drilled into the upper surface of the lower wing, I was able to dry fit the outboard struts to determine their correct angles as you can see in the following shots.
The jig also serves as a guide for the placement of the locating pin holes in the lower side of the top wing. Both the outboard and cabane strut holes are highlighted in this shot and the arrows indicate where I have marked the locations for the rigging wires.
This next shot shows the outboard struts have been fixed into place and the cabane struts have been dry fitted to the upper wing. Also indicated with the arrows are the brass pins inserted for the cabane struts to the fuselage and the outboard struts to the upper wing.
In addition to all the work with struts has been ongoing clean up and fettling of other parts. The underside fuel tank panel has been cleaned up to fit properly under the fuselage and wing, but the panel is almost too bland. Photos of museum aircraft indicate that rows of rivets are quite prominent. As such I broke out the pinwheel to add some rivet detail to this tank – the photo below has been tweaked a bit to bring the fine detail to light.
Finally, I have started work on getting the engine parts cleaned up, starting with the engine cowl. This cowl ring is pivotal in getting the engine assembled to the correct dimensions. Looking at the two pieces the first thing that worried me was the fact there is, again, only a butt join holding it all together. To make it a more positive fit and make sure it aligns properly I have inserted some 0.75mm styrene rod to serve as locator pins. This should go some way to both help with panel alignment and to give a stronger joint with more connecting surfaces for the glue to bind to.
That's pretty much all I have in terms of a progress update for now. As always, thanks to all who drop by for a look.