Scratchbuilding the Dove part 8

Once I had cut the entire blank to profile, I marked out the outline of the upper access hatch.  At that point I inverted the master,  marked off the plan outline and took the work to the band saw and cut the blank to plan outline.

The cockpit master cut to plan.  Next step was to install a pre-formed access hatch made from twenty pound modeling foam,  after first cutting it to contour.

The Rosetta Stone - The Access Hatch   Why do I call the access hatch the Rosetta stone? Because in its shape is the key to how the rest of  the cockpit master will be shaped. Sure, the plan and profile outlines were well defined by Phil in his drawings, but (as with the hull) he failed to provide a series of cross sections along the length of the cockpit to identify its contour - a problem left for the builder to work out for himself.

However, with the access hatch we have its outline in plan and profile. We also have excellent photos of the cockpit and the access  hatch open and closed - a very exacting access hatch can be contoured after careful photographic analysis. And that is the course I took.

I made the access hatch from the denser twenty-pound modeling foam. This material would give me a better defined, stronger, and easier to drill and mount piece. After cutting a blank of modeling foam out with saw, I marked the plan view of the access hatch on it using the same template  employed to mark off the top of the cockpit. It was then carefully cut to plan.

At this point the access hatch piece was placed atop the cockpit piece and two vertical one-sixteenth inch diameter holes drilled through each. The holes ran through to the bottom of the cockpit piece, the reason explained later. These holes would, in the access hatch, accommodate brass pins that were glued in place. The holes in the cockpit piece receive these pins as a friction fit. What was formed was a self-keying set of mounting pins that fit exactly with the holes in the cockpit.

From that point on every time I wished to integrate the access hatch and cockpit pieces they would fit tightly and in perfect registration with each other.
 

Lower left is my first attempt to make the cockpit master.  I had mis-marked the location of the access hatch, and the piece had to be  discarded after finding the flaw.  The upper piece is the new cockpit master, yet to be cut to contour.  Note that the as yet to be cut contoured access hatch has already been drilled out and is  ready to accept the alignment/securing pins.

You'll observe in photo #6 that I show the discarded cockpit/access hatch pieces next to the in-work new cockpit/access hatch pieces. The idea is it  illustrate, in one photo, a preliminary and advanced state of construction. Though flawed slightly, the discarded pieces clearly show the contours that would later be cut into the new pieces.

After installing the pins in the new access hatch piece, that unit was test fit atop the cockpit. After a tight non-shifting fit was assured the two items were separated for further work.

Because of their different 'harnesses' I first worked the access hatch to contour while it was off the rest to the cockpit master.  Once shaped, it was fit into place and the rest of the cockpit brought to shape to conform to the lines of the access hatch.

I took great care with a moto-tool sanding drum and made the initial cuts to the access hatch shaping it to contour.

Working to shape the cockpit access hatch piece.  Note the use of radial lines and hash marks to help me visualize the geometry of the  piece as I cut it to contour with the knife and sanding stick.  I use a Sharpie marking pen on this kind of work-- it has an ink density and fine line much like that of an expensive drafting pen.  The Sharpie is an important shop tool

Once I got the work down as far as I dared go with the moto-tool, I shifted to a sanding block to finish off the contouring of the access hatch. The  above photo shows the nearly finished access hatch test fit atop the cockpit, but not completely pushed down onto it. Note that I inked two radial lines. Eye balling along the right and left side of these lines gives a quick check as to the symmetry of the work. The pencil hash marks denote material that still has to be removed. With this shot you get some appreciation of how the access hatch guided my hand as I later contoured the  cockpit piece.

Take another look at this photo. Note the close proximity of the two different densities of Urethane modeling foam and the smooth finish to the denser access hatch piece compared to the rough  texture of the less dense cockpit piece. Also worthy of mention in this shot: my use of a Sharpie marking pen on this kind of work - it has an ink density and fine line much like that of an expensive drafting pen. The Sharpie is an important shop tool. I get mine from Office Max.

Use of a cockpit profile 'negative' marking template.  this aided me in finalizing the profile shape of the cockpit/access hatch pieces

One more marking template was made and used to assure that the assembled access hatch/cockpit combination corresponded in shape to the plans profile  view. This negative template was cut with the aid of the profile template and used by placing it atop the assembly. I was looking for a tight fit between the top of the masters and the outline described by the curved  negative template. A high point was identified on the access hatch and knocked down to correct profile with a few passes of file and sandpaper. Photo #9 shows how I used this negative template to check the parts profile  shape.

Yes, yes, by now you must be screaming about all the hard work involved in making so many tools (marking fixture, cutting templates and marking templates) to assure symmetry of the parts under construction.

Well, Boy's and Girl's, these are just some of the many chores the careful Craftsman performs with precision if he wishes to achieve quality work.

Model building is often difficult, exacting work. Not  everyone is up to the challenge. Many who think they are soon fall to the way side after finding the activity just too demanding of their skill, time, and patience. Most 'wanna be' model builders quickly retreat to the safer, less challenging activity of common kit assembly.  Not everyone has the character or basic motor skills to be a proficient Model Builder. Nobody is created equal - that is a demonstrable fact! You either  'got it' or you don't.

In part 9, we look at Cutting The Cockpit To Contour