5"38 Cutaway Turret Complex; CAD and 3D Printed

Finished up with the guns for a while until painting and assembly. Added or fixed the broken levers and handles. I permanently glued the gun mounts to the frame. It’s okay to do that now since it makes a stable assembly for further work on all the ancillary equipment. I also got the rammer hydraulic lines in place and replaced the first long one with a more properly shaped one.

I cut out my gun house patterns, applied a light coat of MicroMark Pressure Sensitive Adhesive and stuck them onto a large piece of 0.040" styrene sheet. This represents about 2" in scale, close to the scale 2.5" armor on the gun house. Instead of using the right and left side gun house templates, I just cut one and used it to trace the other side. I then clamped them together and sanded their edges lightly so they identical. When possible, I used the corners and edges of the sheet for at least one of the sides.

Here’s a closer look at the gun house side…

All four of the top pieces had to be exactly the same width and the gun slots had to line up. So I used one of them to trace the other three, even though I had drawn them and they equal in the drawing. This eliminated the slight variations that would crop up depending on which side of the line I was cutting. I got most of them cut out today. I tried the sides onto the 3D printed curved back wall and was rewarded that the corner rabbett that I printed perfectly blended with the styrene sides. I don’t have any drawing stuck onto the side piece that I traced, but I will need the location of the side access hatch. For the actual hatch cuts I will trace the real one. I’m also going to located and drill all the holes for the foot rungs while it’s all in the flat. I have to do some finish sanding on the edges and the gun slots. I also have to sand bevels on the mating surfaces of the angle pieces so they mate properly. All joints will have 3/16" styrene angle as does the prototype.

Meanwhile, while printing parts for another project a calamity happened. After a major print failure… and I mean “major” in the sense that the only thing that printed on the build plate was the base raft. All the rest was a series of variously shaped blobs stuck to the FEP teflon film at the resin vat’s bottom.

I was able to remove the crap on the bottom without destroying the FEP (I hope), then I looked at the LCD protective plate and saw a series of bad cracks propagating across the LCD. I thought it was the tempered glass protective plate that I bought to protect the delicate LCD below. But when I removed the undamaged cover plate, I realized that the cracks were in the LCD itself. I did a light test and it failed miserably. Half the screen was disfunctional. The cracks are quite obvious in this image. I need to understand why the print failure happened in the first place. I’ve tried printing this part three times with not very good success before the complete mess that this attempt was.

I ordered a new screen from Amazon which will be delivered soon and I’ll install it on Monday and hopefully, all my projects will continue uninterrupted. Elegoo has a new machine out that uses a Texas Instruments DLP chip. This device has been around for a long time and since it projects its pixel image though lenses and mirrors to the resin vat and doesn’t get any physical pressure from the z-axis lead screw and stepper motor. It was the plate attempting to compress those hardening lumps on the vat’s bottom that caused the damage to the LCD screen. I think my next printer is going to that technology. So this summer I’ve added a new motherboard, new touch screen and now a new LCD screen. Wish me luck. I can continue to build the sheet work without the printer running, but I really need it.

I found out from Ryan today that the splinter deck is only 30" high, made up a massive series of square compartments with manholes separating each of them. I will only be showing a little bit of that detail. It’s only function is too isolate the magazines below from any shrapnal that may attempt to get there from action above. I don’t believe any of the Iowas saw any action that involved this structure.

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