New Naval Destroyer – USS Zumwalt

The US Navy is developing a new class of guided missile destroyers known as Zumwalt.  Designed as a multi-role ship, the main focus will be on land attack. State-of-the-art stealth technology is incorporated into the design, which will result in the radar signature being similar to a fishing boat, despite being over 40% larger than the current Arleigh-Burke class destroyer, which is 510 feet long.

It will be constructed out of composite materials, and features a tumblehome wave piercing hull. Water sleeting along the sides, in addition to passive cool air induction in the mack, lead to reduced thermal emissions.

Many of you probably remember the WW2-era destroyers and battleships that employed dozens of large-caliber cannons to provide naval fire support, and have probably noticed the absence of such large cannons on today’s ships in place of guided rockets. The Zumwalt class of destroyers has a planned naval surface fire support role and will have two 155mm guns. They will fire guided artillery shells that can travel 63 nautical miles inland. It will also be built to house the new electromagnetic railgun that is being developed by the navy.

An interesting article on the Zumwalt can be found here.

 

 

Picture this

One of Janis’ concerns was just how big the front and rear windows of the house would be. She has some difficulty visualizing how things will look when done – especially when all we have is some drawings and the plans. Rather than just press on and risk a very costly redo later I find it a worthwhile exercise to take the time to mock up a project if it is possible. Since we are creating the window bucks, which are the same size as the final windows it was an easy matter to stand up the biggest windows of the house and space them out as they will appear in their final configuration. While we will do one more check after I weld up the structural steel and put all the pieces of the window assembly together, doing it now while we had just the plywood cutouts meant getting an approval at this stage would take away all expensive risk down the road. I had cut out two plywood pieces for each window. These were fastened together with two by fours in-between so they mimicked the actual windows in depth as well as all the other measurements. Here’s a shot before the second sheet of plywood was screwed on. I won’t glue these pieces so we can reuse the pieces that are large enough.
I measured things out and even drew a few lines on the bucks to show where the window frames would go. Then I called Janis into the shop so she could see for herself. These windows will be two feet off the floor so I provided Janis a clean place to kneel, giving a better feel of just how high and BIG this window set will actually be.
All fears of possible being too small vanished in an instant. We checked out the other windows as well and now we can go forward with no fear of changes down the road.
Stay tuned for more…
-dan

Published with permission from precisionboard.blogspot.com. Source.

Making the pieces puzzle shaped

This morning I fired up the MultiCam to cut the pieces for the window bucks. There were sixty-four pieces in all, cut from 25 sheets of half inch plywood. In spite of having other projects on the go that distracted me the task was done in less than two hours.
Now it is time to assemble the many pieces to create the forms or bucks for the windows.
-dan

Published with permission from precisionboard.blogspot.com. Source.

First pieces of the puzzle arrive

We’ve routed a lot of Precision Board into some pretty wild signs over the years. In the next days our MultiCam will be pressed into service once more. But instead of routing our normal three dimensional stuff the machine will be used to cut up a whole lot of plywood for the window bucks of our new house. 
The materials arrived today. 
I’ll be posting pictures soon of how all the pieces go together.
-dan

Published with permission from precisionboard.blogspot.com. Source.

The Method Part II – Demolding the Parts

Following up on my previous post on my method of making high quality, re-usable tooling with CNC machined foam and Stretchelon bagging film, here’s how things tend to go on the demold side.  First, turn off the pumps, and then remove all the secondary fabrics/films that are bagging the part:

I’ve left the peel ply on here, because the parts are still pretty darn soft, but everything else has gone into the trash.  Now, simply get some air underneath the layer of Stretchelon covering the mold, and then pull the parts up, along with the film:

Now, just simply peel the Stretchelon off the parts – if you’ve used mold release, it should come off very easily more or less in one piece:

Presto!  And the molds are totally unharmed – same as they were when we started.  Here’s a closeup of the surface texture of the finished part:

Yes, a bit of texture, but like I said before, a few swipes with some 80 grit to prepare for primer and the texture just vanishes.  Or, if you really want a smoother texture, just get more dense tooling foam.

Published with permission from Better Living Through CNC.