1:72 Complete Iowa Battleship 16"-50 cal Turret with interior down to the magazine (1 Viewer)

[Builder 2010]

I've been wanting to make a detialed 16" turret for years, but the tech wasn't available to enable me to do it. Then along came my resin 3D printer in 2019 and this year Takom issues the gun house of the Missouri Turret in WW2 configuration. The Takom model is just an empty shell, but that's alright since I was fully prepared to build all the interior. I started collecting drawings and images for this eventual project years ago when I was building my second Tamiya 1:350 Missouri in 2012. That ship turned out to be an award winner.

I was led to contact the curator of the USS New Jersey Museum Ship in Trenton NJ, and after presenting my preliminary drawings, was given a green light that the model would be put on display at the ship. I was also given a similar offer for the Missouri build in the captain's cabin of the Missouri on display at Pearl Harbon. In that case, I had to get the model there on my nickel without wrecking it and that didn't happen. In the this case, I can hand carry the turret model to the ship since my wife and I travel from Louisville, KY to Philly several times a year to visit family and friends.

The most challenging aspect of the entire turret project were the main guns themselves. I lacked dimensioned drawings giving a complete picture. The curator measured a couple of points on the actual gun and gave me two critical dimensions from which I was able to approximate the rest of the guns' shape. I then found an image of a separate gun slide casting which enabled me to finally get that difficult geometry close.

I have a new Elegoo Mars 3 printer which is 8X the resolution, 4X the speed and 30% greater capacity than my Mars Classic which it replaced. All of these improvements made this new project possibe.

Since I'm blogging the day-to-day on several other forums, I won't repeat all of this, but I'll give you some highlights.

Takom Iowa Class Mark 7, 16"50Cal Turret with Full Interior Start-to-Finish

Thanks! Moving along… Started the print for the interior cylinder of one of the two projectile decks. This is a complex five-hour print that will determine the process going forward. It will be done before 8 p.m. tonight. While that was printing I cleaned up the projectile hoist prints and...

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I purchased the after-market turned metal gun barrels, but they needed further modification. The model uses plastic, two-part guns that are glued to the faux gun bloomers which in turn are glued to the glacis of the gun house. Since I've created the entire gun system that lies behind this, I needed to the guns to mate with the actual gun slide. So I turned the diameter of the gun's tail to 7/16" and made my gun slides to be able to accept this smaller diameter. The kit's bloomers just wrap around this.

Here's the gun system: The little-seen undersides show the massive recoil cylinder. The gun is fired by a primer cartridge inserted by the primer man from below while standing on a platform on the pan deck that lies directly below the guns.

The gun's topside shows the two counter-recoil cylinders that are predominent details in any pictures of the gun room. They bring the recoiled gun back to the battery (loading) position after firing. I had to draw every single thing you see and the number of drawings is getting massively large.

The forward part of the gun slide was a single print as was the yoke (breach block) and the breach plug. This is 1:72 scale so the details are small and delicate. I had to do a lot of repair on some of these parts due to that fragility.

Everthing, everywhere in the turret on all decks is heavily partitioned to reduce the spread of fire from any section to any other section. Each gun fits in a tightly spaced compartment with just inches on each side for clearance. The back area of each gun pit has the powder hoist access door, the projectile hoist ending in the cradle and the spanning tray that extends to guide the projectile and the powder bags into the gun's chamber. It also has the ramming mechanism. And it has all the controls to make this stuff work. I'm positioning two guns in the 5° elevation loading position with their breaches open and one in the 45° maximum elevation firing position. . I chose to print this entire area as another single part print.

I opened the gun house roof to show the insides and haven't yet decided whether or not to inlay a piece of clear acrylic. I've had differing input on the subject. I've asked the curator to describe how the model will be protected in the ship and will base the decision on that input.

This image is just trying stuff inside.

The gun house back portion is the officer's cabin. It is separated from the gun pits by a bulkhead penetrated by 6 entry hatches. The three larger doors access the guns and the smaller ones to a tiny compartment where the powder hoist operators sit for each gun. It also contains the massive long-base optical range finder. All three turrets had these during WW2, but the RF was removed in the forward Iowa Class turrets during the 1986 refit due to their propensity to absord sea water in heavy seas. I'm keeping the RF so I'm following the WW2 configuration.

Again, I printed the entire rear compartment as a single piece which includes the RF, the ramming machines, and the fire suppession water tanks.

Right now I'm working on the one of the projectile flats. There are two of these decks that consist of three deck rings: The middle ring is connected to the rotating cylindrical core that rotates with the turret; the outer ring which is stationary attached to the barbette's outer walls; and the inner ring which rotates independently with its own electro-hydraulic power system geared to a ring gear in the inner structure. Active ammunition is stored on this inner ring and can be brought to the three projectile hoists as needed. Additional ammo is stored on the out ring. All active ammo comes from the inner ring. I'm printing the central core as a single piece, but the machinery as a separate print. The middle ring is finished including the three projectile hoists.

The gypsy heads protruding from this deck are also powered and enable the crew to parbuckle the 2,700 lb projectiles to be moved around and into the hoists. The decks appear to be sheeted with copper. every surface that touches powder or projectiles is non-ferrous so there are no chance for sparks to cause havoc. The only steel that is contacted is when the ammunition is finally loaded into the gun chamber. I chosent to screw the two halves of the gun house together so it can be opened in case something is amiss. I epoxied wood blocks to the corners to accept the screws.

There is still an amazing amount of work to do until this project is finished. I am going to light various places with small LEDs. The cylindrical parts will be strategically cut away. I thought about making the cylinders using clear acrylic, but am concerned about makings such small cylinders that will work.

This is what's been drawn so far. I'm still noodling how to assemble the massive roller bearing that supports the 2,500 ton rotating turret assembly. The turret weighs as much as a small ship all by itself. I may or may not enable it to rotate. Depends on how it all goes together.

I'll keep you all posted periodically as it moves along.

 

[Crimea_River]

Incredible work and an interesting subject.

 

[rochie]

very nicely done indeed

 

[Wurger]

 

[vikingBerserker]

That's just Brilliant!

 

[Capt. Vick]

Cool...cool, cool, cool.

 

[Vic Balshaw]

Amazing, there no other word for it.

 

[T Bolt]

Fantastic project!
I'm a regular watcher of the Battleship New Jersey YouTube channel

 

[SaparotRob]

With all above.

 

[Gnomey]

Great work so far!

 

[Builder 2010]

Thanks Guys! I love the full-throated support I get on this forum.

I finished cleanup of the projectile flat core. I also made the first cutaway of this assembly. Some aspects did not print as well as I would have liked, partially due to my efforts to print as much as a single part as possible. Even splitting out the machinery (which helped) wasn't sufficient to make a perfect print. But, I'm not one to let the perfect be the enemy of the good and made it work. I am making changes for Projectile Deck #2. The two mating decks had some roundness issues and I'm afraid this is an artifact of the printing process. Printing creates stresses in the part and this can be expressed by warpage. I can't chuck the parts in my tiny Taig lathe so I can do a truing cut to round them out. I had to remove some stock from the inner piece on the disc sander and this was FAR from perfect. I also had lots of supports which created many blemishes that I had to deal with.

Regardless, I'm going to use this assembly. Very little of it will be seeable based on where it is in the stack, and the 16" projectiles that wil surround it except for the cutaway part (which I'm making in the same places as the hoist structures.

I will have to put some of the LED lighting in these spaces since they will be in the dark.

While working on this project I'm assisting my HS graduating senior create his capstone project. In this case it's a small Tesla Coil being driven by a high voltage power supply constructed from a TV flyback transformer. Today we wound the 1,000 turns of 32 awg magnet wire onto a piece of 2" PVC pipe. It took almost two hours with me turning the spindle and apply some slight pressure sideways on the advancing turns as he guided the wire onto the spindle and kept tension on the wire spool. We first tried to power it with big DeWalt, but found out very quickly that it was impossible to control. By turning manually I was able to stop immediately if we got a crossed conductor. You can have no overlaps or gaps of the voltage will jump the gaps and it will not function.

He and I built the winding rig out of parts left over from another school project with his older brother a few years ago.

He told me something today that made me very happy. He said that his choice of engineering at Washington University of St. Louis was the direct result of all the time we spent working in the shop. His older brother is also going into his senior year at U of IL in engineering and says the same thing. Pretty darn cool! It's all because we decided to move to Louisville when they were little kids. It was a great decision. Priceless!

 

[Wurger]

 

[Grant Barr]

Just WOW!!

 

[Builder 2010]

Thank you!
Yes! It is priceless! We moved here 13 years ago when I was laid off from the building industry in 2009. The kids were little (7 & 5), and we thought that it would be good to be in a place where we could be part of their growing up. Staying on the East Coast, while being a more expensive place in which to retire, was also 11 hours away from the kids and grandkids. Our son, and family (two granddaughters) live in State College, PA, but Louisville offered us more. It was probably the best strategic decision of a lifetime (besides marrying my wife of 54 years). It worked out exactly as we would hope it would and we were an integral part of their growing up and they became terffic young adults.

Here's Jack with the finished and (non)working Tesla Coil. The used flyback transformer was defective and produced no voltage, but burnt out the 22ohm 2W resistor. There was no way to test this device. One of the TV repair shops near us closed down two years ago, and another, which we did find, no longer had any test equipment to test such a device. Flyback transformers got their name from providing the high voltage to the electron beam inside CRTs and drove the beam back to the starting position for the next raster, ergo "flyback to the start". They're an obsolete technology, and while they are still readily available on eBay, their wiring is a mystery with 10 to 12 pins at their base all leading to different configurations of voltage taps driving a lot of the CRT requirements. But the project looked great! Jack learned how to do precision soldering, cut and glue acrylic, read schematics, build circuits, wind coils, etc. He didn't care if it worked. It was fun and probably out last project together in the shop.

Here we were doing the two-man job of winding 1,000 turns of 32 gauge magnet wire. you can't have any gaps or cross-overs so it's quite a finicky operation. Took about 1.5 hours to wind. You put down a coat of clear uretahne first, let it set until tacky and that holds the wires from unraveling when you let off the tension.

I was turning the drum while pressing the last loop tight while Jack appled the wire with one hand and provided resistence on the wire spool so it wouldn't unravel and kept the strand running tightly against the previous one. I found a video where a guy built an Arduino computer controlled winder using two stepper motors. You just dialed in the wire gauge and number of turns and voila, a perfect coil. Great if we had an unlimited budget and lots and lots of time. We built this in four days.

When I left public school shop teaching in 1975 to start a career of industrial and business training, I really didn't know the effect I had on my students. I knew that my shop(s) were kind of a lessez faire environment, where the kids could relax a bit and we did some great things, but I really didn't know if I was making an impact. Two years after I left some former students visited me at the company in which I worked and explained what a personal loss it was for them when I left. If there was a way of conveying that before I left, I may have made a different decision. As it was my decision to leave was a good one.

I realized that I forgot to open up the powder hoist access holes on projectile ring that contained the hoists. These didn't have to be nicely done since they're out of sight, but they need to be able to pass the powder trunks through to the powder handling flat. I traced the opennings from the center rotating piece and cut the openings with the Dremel with a carbide 1/16" router.

I realized that I can print every deck, the roller ring, and the ring gear ring in their entirety on this new larger printer. I decided that making an operating roller bearing ring was an excercise in futility since no one should ever be in a postion to rotate it. I could then, thereofre, make it as a non-working assembly saving a lot of grief in figuring how to build an operating one. By making this and the ring gear each as single parts solves the problem of them being out of round.

One of the biggest pieces to make is the Pan Deck floor. I was just able to fit its diameter on the machine. I was assembling the traversing machine in my head and was having trouble figuring out how that was going to go. Then I realized that there was sufficient capacity to have the machinery attached to the part for printing. I also able to include the gun pits in the print solving another fabrication challenge.

It's a huge print as seen in this shot of it hanging on the machine when it was finished after 11 hours of print time. Just for comparison, my old printer (which couldn't fit this part) would have taken 44 hours to print this part.

The part cleaned up nicely and after some minor sanding and post-hardening, here's the finished floor. I will have to wrap the slightly tapered skin to finish it up. Inside go all the partitions, the projectile and powder trunks, a ladder, and lighting. Topside view: Notice there are three floor hatches to the Eletric Deck that lies belore. One is in the center compartment floor, but the two side entries are in the gun pits themselves.

Bottom view: showing the massive pinions that drive the entire turret around the traverse ring gear.

The 16" projectiles needed painting. After a quick Google search I found that the high-explosive rounds were O.D. with yellow tips and silver fuse tips, the armor-piercing were black with yellow tips and silver fuses, and the training rounds were all light blue. I airbrushed the first colors.

I then filled a small container with yellow to a level corresponding to the depth of the tip paint and dipped the projectiles into the yellow to paint the tips.

After doing the same to paint the silver I tried them on in the deck. I chose to dip instead of masking because it just seemed a more efficient way to go.

I'm getting itchy to start painting and building all of this, but there's still more to do. With the success of printing the big parts, the build phase is coming sooner rather than later.

 

[Wurger]

 

[Vic Balshaw]

I think I've used the term 'Gobsmacked' before. I repeat 'Gobsmacked'.

 

[Gnomey]

Lovely work so far!

 

[Builder 2010]

Gobsmacked is a great word!

Last week I experimented in printing the entire electric deck with all the partitions as an integral unit. I didn't include the machinery. It printed about 95% good. The 5% bad was so bad that I sraped the part. But it taught me what needed to be done to make it successful. The very lowest supports on this massive part were too short to properly form well and provide the correct mechanical strength. For the next attempt I'm raising the part 5 mm more off the build plate and adding more supports in some strategic areas.

I chose not to print it again... yet... since I just finished drawing ALL the machinery and chose to print some of the machines integral with the center to partitions. I'll explain later on. The machinery load on this deck is freaking awesome. I can imagine that being a sailor having to work at the four stations on that deck must have been driven nuts. There were 7 electro-hydraulic systems whining away. One of them, the training drive was powered by a 300 horsepower induction motor. It had a main hydraulic variable displacement pump and two auxilary pumps. Some of the other pumps also had scavenge pumps in addition to the main pumps. In addition to the noise, the overwhelming smell of hydraulic oil would have been overpowering. It wasn't a job for wimps. And through all that bedlam, they had to pay very strict attention to instructions and matching dials that elevated and traversed the big guns.

Here's the entire machinery suite on the electric deck.

The key is:

1. (3) Projectile Hoist motors and a-End hydraulic pumps (B-ends are at the projectile flats at each hois)

2. (3) Elevation System motors and a-end hydraulic pumps (B-ends are up one deck on the pan deck)

3. (1) Travese System motor and a-end pump (twin b-ends are up one deck on the pan deck)

You will notice on the above the pressure manifolds from the travese pump in the middle compartment. Once again I was challenged with the dilemma to get the printed motor system into those openings in the partitions. Also, the center projectile hoist lies across one of those partition openings.

To solve the problem, I extracted the two middle partitions and will print them with all the machinery attached. I will then just be able to drop them during assembly. All the rest of the pump systems will be printed separately and which will facilitate painting.

So the main print will look like this.

In addtion to the pump machinery I also finished the crew stations. These are the jobs I was lamenting as being plug awful.

That covers most of the hydraulics. What was left was the machines to drive the powder hoists. I had previously draw the hoist drum and b-end, but neglected to draw the a-end motor and pump. These lie together as a single installation in the spaces between the main guns.

Here's how they're positioned.

And here's what I'll be printing. It's not 100% accurate, but it gives the flavor.

I'm also going to reprint the projectile flats. After further study, I've got the hoists positioned improperly and the central rotating part needs taller partitions. I just have to keep ordering resin...

We're rescheduling our Philly visit to before (or after) July 4th and I want to reschedule the Big J tour also. I'd like to have more to show Ryan by that time. What's left to do is probably about a solid week of printing. Painting, lighting and assembling will take time too.

 

[Vic Balshaw]

Awesome!

 

[BertUS]

Great work, I see you prining with the Elegoo Mars 3? What kinda resin you use, I think you can lower a bit in Exposuretime, some parts looks like a bit overexposured and seeing the printinglines it's also a bit overexposed. But for the work, excellent, I know how much time it's cost to desing, draw and print all the stuff, so respect