A journal following the history, design, construction and operation of Bernard Kempinski's O Scale model railroad depicting the U. S. Military Railroad (USMRR) Aquia-Falmouth line in 1863, and other model railroad projects.
©Bernard Kempinski All text and images, except as noted, on this blog are copyrighted by the author and may not be used without permission.
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May 28, 2024

Get to the Choppa!


The punch list on the diorama is shrinking. On Saturday, Jeff Hammer stopped by and installed most of the remaining barbed wire sections.

Meanwhile, I started scratch building the Landing Craft Tank Mk 5 (LCT) number 2227. 

I decided to use styrene parts applied to an acrylic base. I cut the acrylic base on my laser. I also used the laser to cut some of the larger styrene parts. However, the laser cannot cut small parts ins styrene, especially those with sharp angles. So, it was time to...

GET TO THE CHOPPA!

LCT almost ready for paint


It has been a while since I scratch built using styrene since most of the work on the Aquia Line I do with wood. I have an old NWSL Chopper that has seen better days. But it did a good enough job cutting the parts for this model. Styrene is easy to work using scribe and snap, model cement and putty. The chopper allows making repeat parts easy.

One of these days I need to upgrade to the Ultimation Slicer. It is a great tool. Some of my friends have the Slicer and say it very handy.

I have the Ulimation Sander and Repeater shown at the left. That is an excellent tool for working with styrene and wood. I use the Ultimation Sander to clean up cuts. The miter table is very precise. The gap between the sander and the disk is very small, making it easy to use on small parts.  You spin it by hand, so it doesn't melt plastic and it doesn't shoot dust everywhere.

I used to have a small Proxxon disk sander for modeling. It was cheaply built primarily with plastic.  It broke when it fell on my floor. The miter table it came with was toy like. It could not do small parts due to the gap in the table and the disk, and it was very loud with a shop vacuum attached. 

When using the laser to cut styrene it seems best to have the laser make slashing cuts that extend beyond the part you wish to cut. For example,  to make a right angle you would make a X-shaped cut instead of an L- shape. That seems to minimize the time the laser is in contact with the styrene at the vulnerable sharp corner, as the laser will speed by the spot where the corner will be, giving the plastic some time to cool 


thus minimizing melting. Or course, this technique doesn't work on parts with interior corners, like a window frame.  The other technique one can try on styrene is multiple light passes with a lower power setting that does't cut through fully. 

For the LCT model, I used some photo-etched stanchions and 0.015 inch phosphor bronze wire that I had on hand to make the hand rails. They are very sturdy with just CAA. I had a set of stairs and some plastic ladders in my spare box that worked.

I printed some additional parts such as the life raft, watertight doors, bollards, and vents. I added lots of punched styrene disks and other small plastic parts. 

The LCT lost its ramp during the fighting due to a mortar strike after the tanks unloaded. It became beached in the shallow water for quite a while. Its anchor also malfunctioned. While it was stranded,  it received numerous hits from small arms fire and fragments, some which created holes. But none of the crew were injured, as they stayed in the armored part of the hull until they could get moving again.



LCT 2227 loaded with trucks probably before D-Day

Nice color photo of a different LCT in Italy. It shows extensive weathering and provides some detailing ideas.

2 comments:

  1. Does the ultimate slicer make perfectly square cuts, or does it leave an angle due to the shape of the blade (which then needs to be filed flat)?

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    Replies
    1. AnonymousMay 28, 2024

      Supposedly, yes. Square cuts due to special blade.

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