The last thing I said in my last update was that Part 7 was completed, unless something unexpected happened. Well, I had barely typed the words when the unexpected did in fact happen. I received an e-mail containing photos kindly advising me that the rudders and stern planes did not have “bearing roots” as shown on the plans I have, and thus the way I built it. Soooo, I changed it yet again. It was worth it. Not only is it fun and gets easier and faster each time, it really looks better.
Having completed the Stern section, I decided to give all of the hull pieces the flange treatment and put it together. The first piece fit nicely. Everything was the right size (comparatively) and properly aligned. When I got to the next piece (Part 4) the diameter was significantly larger than the diameter of the piece it was supposed to mate with. It was the first center piece, so I knew what the diameter was supposed to be and it was spot on. That meant that everything before that was a hair too small. We’re talking about 0.02” in 2.4”, but it would have been noticeable and although it probably could have been sanded down, I might as well get the parts right to begin with (if possible).
This would seem like a small problem. All I needed to do was scale the entire rear assembly the amount needed to make it the right size. The problem was that the connections were made before, when they were mis-sized so scaling the one piece up threw everything off, and it was kind of a bugger trying to redo it. I tried to patch work it and it probably would have been faster to simply remake the entire part. In any case, I finally got it done and moved on to something different for a change, the waterline.
I started by aligning the”model’s” Dunce cap tip with the Dunce cap tip on the plans. I then, used ellipses and arcs to trace the waterline as marked on the plans. When I got to the straight part, I realigned the model so the bow of the ship was aligned with the bow of the plans, and again traced the plans using one big ellipse (how convenient!).
At this point I was curious as to just how much AutoCad has improved recently so on a whim I typed “projecting a polyline onto a solid, and TADA! The PROJECTGEOMETRY command does just that, it projects lines or shapes from a flat surface onto an irregular shaped one. You just simply place the line you want projected over the object you want to project it to and presto, your flat shape conforms to the shape. In the image below, I had just projected the traced waterline onto the hull.
The only problem is that at this point, the projected line is a so-called spline. Splines are difficult to work with and can’t be manipulated like I need. However, I was able to use the projection to align the traced polyline I had created. The polyline is needed because that is what I used to extrude the future “scribe” line on. I used a 0.02” wide x 0.1” tall box with the ends filleted at 0.05” to extrude around the polyline. This created a scribe 0.02” wide of varying depth due to the nature of the surface, but typically approximately 0.04”-0.06” deep.
Now let me say that when it comes to scribing widths, I am pretty much clueless. My investigation into the topic was limited to measuring the scribe lines in the rudder and radio towers from the 1/350 scale Essex kit, using a Micromike I obtained years ago, that has divisions of 0.002”. The thicker more pronounced lines in the rudder appeared to have polygonal cross-sections with bottom widths of 0.01”and top widths of 0.02”. The thinner lines were 0.01” wide, so those are the dimensions I’m using, 0.01” for less pronounced features and 0.02” for more pronounced features. Right or wrong, that’s what it is. Ideally, I would send a test piece to my buddy with different size grooves and protrusions, but I certainly don’t want to wear out my welcome before the model is built.
Anyway, here are some images of the way it came out.
Next is the Anti-skid coating outline.