Nothing to report on the Greenling model. I haven’t heard from my buddy in several days and am not sure when he returns from China. I found a good way to fill the time though.
Some of you may recall that, before I decided to build Greenling in AutoCad, I found a print (see below) of all of the Permit class submarines, and considered replicating it in 3-D with 1/700 scale models. Since I didn’t have anything going this weekend, I decided to make it in AutoCad.
For no particular reason, I decided to build Jack’s double screw first. From images that I have seen, mostly on models, the forward screw was a seven bladed propeller similar to the single screw I made for Greenling, but the hub is more or less flat, instead of angled. The aft screw, contrary to what I first thought, had only 6 blades, although their shape seemed to be roughly the same as the 7 screw blades. I consider myself fortunate to have discovered this, because I had looked at screw pictures numerous times before I noticed it.
The images below show the process I followed to make the screw. In the first image, the screw I made for Greenling is in the middle (rescaled for 1/700). The screw on the left is a copy the middle screw with a constant width hub joined to it. The screw on the right is a mirror image of the middle screw.
The fact that the aft screw only had 6 blades complicated matters somewhat. To make it, I started by making a hub, using the center hub as a template. This was easy. Two lofted circles did the trick, as you can see on the left side of the figure below. I used this hub for two things. First, I copied it and used it to remove the blades by subtracting it from the mirrored screw. I then attached the blades to it after they were completed. The right side of the figure below shows the 6 blades attached to the hub.
The images below show the making of the screw blades. I cut off all but one and then Rotate/Copied it at 60 degrees intervals. The image on the far right shows the completed aft screw.
Another view of the completed screw.
The image below shows the two screws oriented properly. The spacing is needed for the model to be the right length.
The next images show the space filled and the double screw completed.
Having completed the double screw, I started on the ships themselves, which meant starting over from scratch. I made two different hulls, a short one, and a long one. I assumed that Jack had a long hull, and that the extra length was in the screw, and looking at the size of the space I had to include, I think that it was a good assumption. You may be wondering why I didn’t just make a short hull since I have already built a long hull. Well, there are two reasons. The first is scale as much of the detailing would, I fear, be too small for the SLA to make. I was pushing the limits in many places as it is. The second is that for some reason, I didn’t seem to keep an un-etched version. In any event, it’s fun and I’m definitely getting better and faster at it.
After lofting the hulls into shape, the next thing I did was the rudders, which like the diving planes are similar on all of the submarines in the class (I think. That’s the way I made them anyway). The images below show the rudders, which were made by tracing the foils provided on the plans with lines, arcs, and ellipses, positioning them as shown on the plans and lofting them together. The fact that they are going to be attached to the hull simplified making the rudder because I could just extrude it into the hull. I “painted” the upper rudder black and the lower rudder a shade of red.
The next image shows the completed rudders on the four different hull/sail configurations; short hull with small sail, short hull with large sail, long hull with large sail, and long hull with small sail and double screw. You can also see the diving planes I was preparing to do next.
The next group of images shows the making of the diving planes. Unfortunately, it doesn’t show the foils that I extruded to make the sails, but you can see how I could extend the nose and not have to worry about slicing it because it was going to be joined to the hull anyway. The bottom two images show the completed planes (I really only made one and used the MIRROR Command to make the second one). The one on the left shows the rudders before they were rotated into position and the one on the left shows them after rotation.
In the images below you can see the copying of the diving planes to the four hulls. Note that I used the end of the hull, beginning of screw as my reference point rather than the end of the screw as I did with Greenling.
Next were the sails. Since I had the shapes to do the large one (fortunately they didn’t get lost), I started with it first, as seen in the images below. The body of the sail was easy, two of the same sized foils, lofted together, the top not so much.
I tried a couple of different methods that I didn’t like before opting to construct it out of ellipses, turned sideways and extruded. The two images below show completion of the sail top.
Next were the sail planes, as shown in the next few images. The first one shows the foil sections used to create the plane prior t o them being rotated and lofted. The second images shows the result after lofting, the third after creating a mirror image of the plane, and the fourth image shows the planes rotated to fit onto the sail. Once again, since the planes aren’t to be moveable, I could make them overly long and simply use the UNION Command to join them.
The next couple of images show the sailplanes attached to the sail. Following is an image of the four configurations of the class showing the sail on the long hulls.
Having completed the large sail, it was time to start on the shorter sail. In the images below, the first image shows the island and the 3 arc segments I used to create the section. The green one on the right started as an ellipse that I trimmed. The other two were created using 3-point arcs. The second image shows the shape after I mirrored the 3 segments and joined them. The next image shows the section copied onto the side view of the shorter sail, and the fourth image shows the sail after the sections were rotated and lofted.
In the next series of images you can see how I did the top. Starting with the top left image you can see the line I drew from the center line, perpendicular to the top and perpendicular to the bulkheads. The top right image shows the ellipses I drew using these lines and intersection points to define. The middle images show the top lofted and then joined with the lower part of the sail and recolored. The lower two images show the sail plane construction. Note the extra section added internal to the sail. This was needed to assure that the aft end of the plane was not sticking out.
Completion of the sail plane is shown in the next group of images using the methods previously described for the larger sail planes.
The next image shows the four hull configurations with the sails completed.
In order to mount them to the base I drilled 1/8” holes in the port side, as may be seen in the following image.
And of course, I had to paint them.
With the 4 hull configurations complete, I turned my attention to the frame. The bottom will be a 12” x 17.2” piece of ¼” dark walnut, or some other suitable wood. I used the Box Command to make it in AutoCad. For the sides I plan to use ½” x 1-¼” dark walnut. The outside dimensions of the frame will be 12.5” x 17.7”, and the top edges of the walnut will be routered with a 1/8” diameter bit. In AutoCad I first made a box ½” x 1-¼” x 12.5” and copied it, then made another box, this one ½” x 1-¼” x 17.7”, turned 90 degrees from the other boxes. I then positioned them correctly and joined them together. After routering the edges by filleting them with 0.125” radii, I joined the frame to the base.
When I was originally considering making this, I got on-line and downloaded images of all of the ship’s patches, gold and silver dolphins, and the American flag. I import these into AutoCad and moved them to the proper locations. I then typed in the text, including the Title, some ship details, the ship names and the scale. The final images show the completed display.
This was a fun little side trip, even though it may not ever get built. It all depends on if I wear out my welcome on Greenling. If I don’t and my buddy is still willing and able to make parts for me I will probably have him make these little guys, as well as a couple of other little projects I have in mind.
If I do get to build it, the first thing I will do is revisit the models. So far, I have just the bare hull, sail, planes and rudders with no detailing. Looking at the 1/700 OKB Grigorov Thresher model I have, and using my handy little Micro-mike, I measured some of the detailing features and found them to be between 0.005” wide and 0.01”wide. So, there is a good chance that I will be adding detailing to the two hulls if I get to build it. I would probably add masts as well, and may even modernize some of them by adding the towed array fairing.
As for the graphics and text, there are multiple options. The easiest and cheapest way would be to make decals out of the text, and print the graphics on photograph paper and then attach them by laminating them between layers of Future, which from my experience looks really nice. Another option would be to go all out and take all of the text and graphics to my local trophy shop and have them all printed on brass. Now that would look classy! Of course no matter how I do it, I will include a glass cover on the front, and mounting brackets of some sort on the back.