5" 38 Mark 28 Twin Gun Secondary Battery from Iowa Class Battleships

Great work so far!

Thanks guys! Actually drawing tires is quite challenging. I haven't done one of those yet and I'm sure it would take quite a while.

It took over a week to draw the projectile hoist. It's complex, ambiguous in parts, had penetrations and curve cuts that needed shape cutting, and finally, required some major rework to get it as right as I can.

The rework was this.

This central core had gotten so messed up with multiple diametesr layered in on each other which created voids, reversed faces, and other anomalies that I couldn't get a decent solid image on the slicer in my tests. I finally bit the bullet, stopped screwing around with it and redrew it from scratch. This time it was perfect. All the discontinuities that plagued me were now gone.

I also figured out the routing of the handwheel linkages. Speaking of handwheels, I wanted to make sure that they would print perfectly since they're quite frail even when perfect. If there were joints that weren't true, it wouldn't hold up. That took a couple of hours.

And speaking of hours, it took an entire afternoon to get the lower doors right. Again, when I put them on the slicer surfaces were showing up as invisible. The "Solid Inspector 2" add-in kept showing surface interface irregularities. I went inside the object using the x-ray function and removed all non-functional surfaces and made sure all the face surfaces were perfectly tight. I was rewarded with beautiful objects in the slicer.

One of my other forums is SketchUp's. I post this in its entirety in five forums. The readers in the SU forum are expert artists and offer good suggestions. One was to not scale the 1:1 object in a 1:48 file, but instead, just load the 1:1 object in the slicer and do the scaling right there saving a whole range of copy/paste operations. With this massive file, those take a lot of time. Another suggestion was to set a camera scene facing directly at the tiny 1:1 component so with a click of the track pad, the 1:1 is instantly brought into the center of view. Otherwise, I have to keep zooming in many times to get the object to fill the screen. These zooms take a lot of time with big files.

Here's the finished object Front view:

And the rear view:


I'm going to attempt to print at least this part of the hoist system as a single part. Here's the part sitting on the slicer. It seems perfect. Will all of the intricacies print... who can tell. I only know when it's finished. That's the fun of 3D printing.



I can now work on the powder hoist part of the system. This should be easier since there is no fuze setting linkage, only a single channel per side, simpler doors, etc. There is one complication; the chute follows a curve and seems to change diameter.

Looks great so far!

Thanks!

While it took less time to design the powder hoist portion of this system, it still took 6 days to do it. It is singularly, the most complex SketchUp work I've ever done. This still conforms to my goal for each project I take to push the envelope further and keep increasing my skills. It had all the same ambiguous drawings as the projectile side, plus some more complex geometry, little links that had to be ferreted out as to their purpose and destination. And finally, I had to keep imagining how it was going to print and ensure that every surface and every little appendage was fully solid and attached properly to all the other parts so it would print with integrity. When it was all done, I did one final fit into the master turret drawing and found that the powder hoists were spaced about 2" on each side too wide. Luckily, moving them inwards didn't create any new problems. They have to slip between the main frame rails. I could have trimmed the rails during assembly, but that seemed like cheating.

I incorporated that fully-modeled diamond-plate floor with the hoists to facilitate wrapping the plates around the protruding hoists and to add another piece of structure to keep their spacing.

This view shows the lower portion of the projectile hoist with their respective access doors. I modeled one open with projectile ready to go up to the gun house and the other closed. This is an accurated depiction since its upper doors are open with another projectile ready to be placed in the gun tray.



Those manual handwheels are going to be very delicate. If they don't hold up when printing with the entire assembly, I'll print some separately and add them later.

The reverse view shows the powder hoists and the little aspect that pokes through the floor. There is an operating foot pedal that's also above the floor plates.



I learned how to find and edit materials in the V-Ray rendering engine that's part of my new SketchUp installation. It's more complex to operate then my previous add-on renderer, Podium. It's also more sophisticated, faster (much faster) and does a much better rendering job.

I gave up on the idea of printing this beast in one piece. Instead I designed the two pieces so they will index together during assembly. I did this by adding some more structural steel at the bottom tying the two powder hoists to the central column. While this is not prototypical, I took artistic license to make the model work.

I also split the floor panels and added a lip to align and give purchase to the asembly joint.



Here's the mess of supports needed to set it up for printing.



It's on the printer now and will be done after 10pm. I'll know then whether it's successful or not. Then I'll have to figure out how to remove all those supports without wrecking anything. Wish me luck.

This was the last of the really complicated parts on the project. The rest is downhill.

Great work so far!

I hope your print went well

I was able to get good parts for the projectile hoist after three tries. The first, for some reason, came out 20% over-sized. Something occurred when I made the scaling in the slicer. I don't think it was loading the wrong factor (2.08%), but rather was my entry. I may have double-clutched and got an erroneous value.

It was a shame. It was a pretty nice part.


The powder hoist portion was decent, but the control links were too fine being close to scale size. I doubled their thickness, and also increased the floor thickness by 2X to increase its stability and make the diamond plate texture more pronounced.

The 2nd projectile print, while correctly sized, needed a lot of repair. I broke one of my cardinal rules: Scale thickness doesn't always translate well in the 3D printed 1:48 world. I made the columns prototypically hollow with the twin bores extending full length. The resulting wall thickness was so thin that it ruptured all over the place. It was actually translucent. I attempted to rebuild them with Bondic, and while structurally stronger, looked awful.




As with lots of SU projects, fixing is often more difficult than making it right the frist time. And this was no exception. Took about an hour to fill the bores. I also took the time to strengthen some other dubious connections. While doing this I also fixed a lot of drawing stuff like hidden layers that didn't do anything.

I was rewwarded with a really nice print. I only had to go back and reattached some tiny links and further strengthen the door hinges.


Get a load of those very fine pull handles compared to that #11 blade. I was impressed. I also added some mid-run supports for the long-run link rods so they would have a better chance for printing and after-printing survival.





I had to notch the floor at the front corners to nestle over the gun mount's rear feet. I was worried that after all this work I couldn't install them, but if I moved the powder hoist as far aft as it would go, carefully inserting the projectile hoist sideways between the frame rails, I was able to lower it and twist it into position. I did have to relieve the width a bit at the cross-girders to make it a slip fit.




This was, without a doubt, the most complex parts I ever produced, and is the apex of complexity on this model. With it successfully done, I can breathe a bit easier.

I drew and printed the floor pans that sit between the frame rails under each gun. These are sheet metal affairs in the real deal, and have a curved floor that follows the arc of the gun. I made perfect prints. Perfect, but for the fact that they were about 5 scale inches too wide! I used the drawing of the frame rails for sizing assuming that my printed part was the same. For some reason, it is not. I will redraw and reprint. They weren't the only thing that was too wide for the frames rails. The gun itself was too wide to drop down between the rails. More about this later.

The oil filters and pedestal were easy to draw and print. I drew the tiny hand screws on their caps, not knowing if they'd survive printing and support removal, They did!

I added more stuff and took this image. Starting to get interesting!

![5IP Gun House Auxiliaries

About the guns…

I was unhappy with the prints that I had. The entire trough didn't print well, and the drawings were a mess with lots of hidden layers and voids that lead to print troubles. With the new print settings I was confident that I could do better. The wrong width gave me an excuse to attack it. Like before, making changes can often be more difficult than starting new, but in this case I did sort of a hybrid attempt using some old and some new. Spent all of yesterday afternoon and more time today to get the internal and external geometry right. I have a lot of time to draw as my wife is recuperating from major breast surgery. She had breast cancer 16 years ago, and it came back. The best of bad news is that it appears to be self-contained. She had full diagnostic scans that were all negative and the surgery went well. So we're very optmistic.

I'm having a lot of SU crashes. Sometimes it occurs when doing tricky things like using BoolTools2 on big complex interfaces, but others occure just when I've made a couple on moves. I never lose too much work since I'm doing auto-backups every minute. But it's annoying!

For some reason, connecting the straight side walls to that compound curved rear panel drove me nuts. I know how to do it, by intersecting the flat into the curves and removing the intersected parts, but it was a lot harder to do than it should have been. The assembly was built from a bunch of geometries that would cause surfaces to disappear unannounced if I erased the wrong line.



This geometry was the worse part. I'm very happy with how the curved trough is now designed and it should print perfectly. I still have a lot of stuff to add on, but I'm not worried about that.

Not seeing any of your pics!!!

Looks great so far!

Great work so far!

Really great work!

Looks great so far!

With my wife recuperating from breast surgery, I had a lot of time to do drawing and printing. She's doing well, but will need a short cycle of chemotherapy to make sure there are no bad actors floating around looking for trouble.

Here's some eye candy to look at before I get into the major work done today. The gun house design and printing is about 98% complete. I have a small platform for the gun captain to stand on when he wants to have his head sticking out of the hatch to use the manual site on the roof. I also have that sight to design and print along with some of the communication equipment at the gun house rear.



Things are quiet on the homefront. Due to the nature of my wife's cancer, even though the pathology was clear, will undergo a short cycle of Chemotherapy. All of this will be over in mid-March and we'll be happy when it's done.

With all that drawing time, this is an example of one load with lots of odds and ends for gun house details. This pile includes shaped junction pieces to help me glue the roof plates at the correct angles and those really neat "tractor seats" for the trainer and pointer positions. I had found a bar stool with the correctly shaped seat on the SketchUp 3D Warehouse and then modified it to print and conform to the ship's seat size and shape.



Here's a closer look at the seats. There's one more that's printing now. It's the bicycle-shaped seat for the sight setter position. It's in the pile above, but, the bottom mounting flange was a separately grouped drawing that I neglected to combine with the overall model. When I conveted to the STL and then the printer, that flange wasn't there so the seat pole was just dangling in open space.

This is the pointer seat:



And this is trainer seat. Both are REALLY delicate, but well cured and formed.



The assembly process has officially begun. I glued the gun house base plate to the underframe. Styrene to UV rensin? Only with CA or epoxy. UV resin is impervious to most common plastic solvent.



The print package was the flooring pieces. Ryan sent me photos of all the floor plates in the gun house and I was able to reproduce them with reasonable fidelity. I was struggling with the diamond plate. I had downloaded a piece of this from the 3D Warehouse. The artist didn't group the pattern separate from the substrate so when I attempted to trim or enlarge the sample to fit my various piece shapes, I had to deal with the substrate disappearing, reversing faces, or just being a pain in the butt. Finally, I decided to separate the diamond patterns and group them. This allowed me to shape the substrate, which is quite easy, and then drop the diamonds onto the surface. Since they are their own group, I was able to erase them in one tenth the time it was taking before.

I designed he little box steps at the rear hatch openings to assemble with the curved angle brackets.



Here's where they fit nesltled into the rear curved wall.



I assembled the floor pieces on the frame for fit and understnading the assembly process.



With the base plate in I'm able to test fit and locate all the gun house details starting with the elevation and training pump systems. The training pump was easy since it just has to nestle up against the piping I printed that come out of the b-end hydraulic motor. I marked the base, but when this is painted, those will disappear so I'll probably go back and make some punch marks.



I then test fit the small, diamond-plated flooring pieces.



I did the same for the pointer's side. This was a bit more complicated since the spacing is fixed by the very small floor piece that spans between the pointer regulator, where it sits on a built-in ledge, and the a-end of the pump system. I had to add a small piece of angle to support the aft end of the floor.

The angle:



And the floor piece. It was very hard to see just how this little bit of floor was attached in the real thing. Ryan's photos only show it from above and all the drawings don't detail it sufficiently. I had to fake it.



There are hydraulic lines eminating from the a-end of the pump which I will probably add old-school with solder wire.

The entire mechanism assembly needed some possible positioning on the gun mounts. i chose to use 0.022" phos-bronze wire. I broke way too many carbide drills doing this.



It took some trial and error to get the pin holes in the two pieces so they'd line up. I then drilled and pinned the mounting for the fuze setting regulator. This simple job almost went completely south. I kept breaking the 0.03 2" drills doing this simple operation. I ended up having to drill three diffferent holes to get one without a piece of broken carbide in it.



Fitted, but not glued. This will be glued after the gun trunnion cap is installed on that side.

I drew and printed the sight checker's telescope. This station is only used during trainining exercises to evaluate the trainer and pointer proficiency. I made a lug on the mounting point that serves as a trunnion pin on that side. This solved a problem for me.



While there's a just a couple of details left to do for the gun house, I'm starting on the upper handling room. I first tried to fit the entire wall structure as a single part, but as you can see, the setup on the printer was not ideal. Way too many supports for my liking.





I have a friend with a bigger printer and talked to him about it, but I don't have his printer model available on my slicer. So I went to plan B. Separte the four wall maintaining the nice curved corners. It's those corners that dissuaded me from doing it out of styrene sheet. This permits me to leave on wall open if that's the way I want to approch the cutaway. I did this same scheme when producing the little n-gauge buildings for the exhibition layout. They're printing now and will finish in a couple of hours. Notice, no supports on cosmetic surfaces. Just the way I like it.



Happy to report that the print came out perfect, including the replacement bicycle seat assembly. It's in the ultrasonice cleaner now, and I'll finish them up tomorrow.