Joining the Sections

It took a lot of planning and preparation for this step: joining the two halves of the PRT tightly but still able to be easily removed for storage and transport.

My solution was to use 4 inch lag bolts with thin nuts on the outside of the smaller section. This creates permanent pegs for the front half to slide onto.

First I created a notch in the board a bit bigger and deeper than the nut. Through the center of that hole I drilled all the way through the board. You can kind of see the result in this photo.

Once the first board was drilled, I lined up both halves and screwed them together. I continued the holes through the other support.

I then unscrewed the sections and pulled them apart. I then proceeded to install the lag bolts and check for a proper fit. Overall it worked out pretty good. Here is the final result.

Now that this is done I can proceed to panel the rest of the hull and work on a card stock stand-in for the pilot house.

Adventures in CAD Design

Some call it an art. Some call it cheating. I just think it’s fun!

A couple weeks ago, the teacher in my school’s science department bought a 3D printer. Pretty soon there was a long list of requests from other teachers. After designing these items quickly, I wondered if this could be applied to my PRT model.

First I designed the ‘watch house’ and the vents on the bow. These were my first priority because all of my previous attempts at building this failed. I just built the structure itself with holes for the mast and ‘stilts’.

Once this was done I had confidence to move onto bigger projects. Spurred by a lack of desire to mess with small parts and even smaller angles, I decided to tackle the self-unloader ‘house.’ This was more of an adventure but only took me about 2 hours to complete. Here is a photo of the real thing vs. the CAD drawing.

Finally, I designed the bridge and smokestack assembly. I designed this for the same reason as the self-unloader. My oversized hands make it difficult to produce accurate angles. I just made the top part of the pilot house, so I can just drop it on a styrene ‘cube’ with the lower details already placed. Surprisingly to me, this only took about 2 hours to design. It is complete with insets for window glazings and viewing platforms on either side. (Platforms placed in front in the CAD drawing, in order to fit on the print surface.)

Overall, all of these models (with a couple flights of stairs found on Thingverse) will take 45-50 hours to print. It will use just under a kilogram of filament, which is valued at $20. But this price is nothing compared to the hours and the wasted material to build them from scratch.

My next project will be to join the two sections of the model. That should be completed by Christmas break.If you would like something designed, or if you are just curious about CAD design or 3D printing in general, feel free to post a comment and I should get right back to you.

Paneling the Hull

It took a while, but I finally got around to start building the shell of the hull. Here’s how I do it:

Step 1: Sand the face of the board and line it up board with supports. Sanding makes the wood appear to be metal once it is painted. Make sure both ends are in the middle of a support, this makes sure the ends don’t curl out. (All NSM models come with everything pre-cut for optimal building.) I apply ample amounts of extra-strength white glue, with a little bit of CA glue on top. The CA is for a short term bond while the high strength white glue is for a long term bond. I have moved the first part of the model many times, and have never had any issues due to the joints.

Step 2: Push and hold the board onto the supports until the CA bonds. For the best gluing results I generally place a heavy block against the panel to keep it straight. Wipe up the excess glue and move on to the next panel. Here is the finished result:

It sure has been awhile since I have had a chance to post. Thankfully we have caught a week of wet weather, so I should be able to get quite a bit done. I have been hard at work working on spring finals and spring planting, and also planning and measuring the pilothouse and self-unloading boom. Both of those projects are going to take quite a lot of time, so I will just post updates every week or so as I get going with these.

How to straighten warped plywood

I was toiling whether I should call this post “Landen’s Latest Screw-Up.” After I installed the supports, I noticed that the plywood was warped slightly. Only about a quarter inch, but enough to screw with alignment.

To remedy this, I first poured warm water on the convex side of the board (sorry for the misaligned photo).

Once one side was completely covered, I screwed some scrap 2-by-4’s to the bottom to straighten it.

I will soak again it in a couple more days. Once that dries, it should be good to go, maybe before Tuesday. Just thought I should let you guys know how to ward against improperly stored plywood, so it does not get regarded as a waste.

PRT Rear Supports installed/ How to

I have recently completed installing the 2×6 supports, and I want to share how I do this. Installing the supports is by far the most difficult part about North Shore Models’ kits, but with practice it is pretty simple.

Step 1: Line up the first and last support. This is the most important part of this whole how-to, because it makes sure the supports stay straight as an arrow. First, I measure the distance (I recommend 1 inch) from either side of the base to make sure it is centered. When you are content, drive one 3-inch screw from the bottom, while putting pressure on the support. Once this screw is in, you can move the unscrewed end until it is at a perfect 90 degree angle to the base. Once this is accomplished, place a screw using the same method in the other side.

Once the first support is in, it is a fairly simple task to install the last one. To do this, You must first know the length of the vessel to be modeled, which is included in the spec sheet of all North Shore Models’ kits. I figured the length of the back half by taking the length of the base of the first half (8′), multipling it by 12 to get 96 inches. I then took one inch off for the space between the bow of the model and the edge of the base to get to 95″. Multiply this number by 87 and divide by 12 to get the length in scale feet of the first half, (with models less than 8 feet in length this is the last step). In my case the number was 688 feet, but will vary slightly. Take the footage for the first part and subtract it by the overall length of the prototype (688-1013.5). This gives me 325 feet. Divide that number by 87 to transfer it to 1:1 scale, which gives me 3.75 feet, or 3’9″. This means that the last support’s outside face should be 3’9″ away from the outside face of the first one. Maybe it is not so simple after all :). If anyone gets lost at any point during this step, leave a comment and I will get back to you.

First and last sections installed with scrap pieces to keep plywood from warping

Once you have the first and last supports on, you are nearing the home stretch. First you will stretch a length of tape tightly between the two supports.

This will give you a straight line to work off of. Just butt the support up to the tape check it by looking down the line and screw it down.

Repeat this until you have all the screws set on one side. Now rotate the model to get to the other side. Measure the distance between the anchored ends of supports 1 and 2.

Then slide the tape measure down the support to line them up.

Once the loose end is wiggled into the correct position, it can be screwed down like the other side.

So there you have it. Its a little more complicated than other models you might have built, but it is the strongest model I have ever come across. I hope to start gluing on basswood by next week, but I have to get other things with the PRT lined up first. Remember, for any modeling help, or you are considering purchasing a North Shore Models kit, just leave a comment or email me at landenmelius@gmail.com, and I will get back to you as soon as possible.

“Back-Half” Agenda

I am excited to announce that construction of the last four feet of the Paul R. Tregurtha is underway! Since the first eight feet were more of a learning curve than anything, I am making 3 main changes that will increase the quality of my models without raising the price.

  1. 6 inch supports instead of 12 inch. This will give the model more stiffness, and basswood panels will be less likely to warp while moving the model.

2. Instead of using 4 inch deck panels, I am moving to 8-to-12 inch panels. This will take out all but one of the seams on the PRT, while also opening a door for me to produce seamless decking for older AAA-style vessels.

3. Last but certainly not least, I am increasing side-hull thickness from 1/16 inch to 3/32 inch. This does not seem like a huge change, but it makes a whole world of difference when it does not splinter when drilling. It will also help ward against panel warping while moving, similar to solution 1.



Thank you for visiting this site, and I wish everyone a safe and happy Easter.

-Landen

Wire Working Tips

To make my handrails, I use standard brass wire that I straighten myself. This process is not only simple, but is also a lot cheaper than buying brass rods. 

Step 1: Cut desired length of wire (with a little extra).

Step 2: Put one end of the wire in a vise, and put the other end in the collets of a power drill. 

Step 3: Pull the drill back gently while running it fairly slow. With larger gauge wire, this process may heat the wire excessevly. This process can take 10 to 15 seconds. Make sure to always wear eye safety equipment, as the wire could break.

Step 4: Trim the ends of the wire where the the vise and the drill made contact. These finished wires can be made at any length and for any modeling purpose. Please note that larger diameter (18 gauge) stays much stiffer than the smaller size (24 gauge).

With a little bit of practice, a wire like this can come from from the spool to perfectly strait in under a minute!