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

Amazing.

Utterly amazing.

Great update, yeah, sometimes you have to make decisions in design, and hope, it will get right in the building

Thanks guys. As you'll see in today's monster post, I had a lot of field mods to do.

All right sports fans, get ready for a big photo dump (22). Unlike the 3D printing phase, the construction phase produces a lot of WIP photography with lots of various things going on. I was concentrating on finishing up the pan deck to get it ready for paint, and was still fussing with the gun girder. First let's tackle that.
I found out why the trunnion caps weren't aligning properly. After checking my master SketchUp drawing I found out that I had them on backwards. When I turned them around they fit fine. I also needed to check how the guns were fitting since the position of this girder on the kit base was further forward than the last girder I printed. Glad I checked. The new position was pushing the guns forward by about 1/8" and they were jamming in the kit opening. I didn't want to move the girder back since everything else about the position was perfect including the ofc's booth fit. To solve this problem I made some relief cuts in the gun manlet and the guns fit fine.

I then checked them with the kit's plastic bloomers and everything still worked including how the metal barrels engaged with the gun slide. Whew! Dodged that bullet. All of this mayhem is completely invisible in the finished model.
I then spent a lot of time fitting the gun rear compartments and the powder hoist operator's booths. The reason for all this fussing was the addition of the kit turret floor piece. I did not have that part as part of the design phase. It was just too hard for me to figure out what was what with it and I fully expected to do a lot of "field mods" to get it all to work. My expectations were correct.
The first problem was relieving the bottoms of the compartment prints so they would drop down and back to the correct final position. This was a trial and error affair. I did the cutting with the Dremel Flexishaft and a diamond coated cutting wheel. This job creates a huge amount of UV resin dust and I wore my dust mask so I wouldn't kill myself.

I also kind of knew from the start that my design of the powder hoist operators booths was going to cause a problem since in the rear ship, they share a common wall in the double hoist area as the powder trunks do. I produced them with two side was each. This is what it looked like when those two walls were trying to occupy the same space. Physics won't allow this.

I had to surgically remove on of the walls. I also had to do major surgery on the edges that mated with the powder trunks themselves. Again, I new as I was drawing all this that I had absolutely no idea just how all these pieces were going to interact until I had the physical parts. After removing the wall, they do work together better. I CA's each respective hoist booth their gun compartments since the little observation window openings had to align for the booth to be at the proper height. I'm not worried about the open space beneath since the rear bulkhead butts up directly to these parts.
The other two guns powder carts will be down at the powder flat.

The right gun is going to have the powder door open with the cart in the upper position. It was especially trying to get the cart, the trunk and the rest of it to all work together. This is how it ended up. Again, the alcove part back wall with conceal that opening you see showing the cart's flank.

The last gun girder task was putting the thin styrene veneer on the rear compartment to act as the turret base plate. I made a paper template and then transferred this to the 0.020" styrene using the same PSA technique I used before. I will be using this technique a few times before the job is done.

I test fit the rear compartment print to make sure that small lift the floor gave didn't cause any problems. it did not. This floor will have the non-slip flooring in the walkway like the prototype does.

I believe I can paint the gun girders now.
I got bacl to work on the pan deck. I had made a paper template of the transverse bulkhead that runs athwartship just behing the training machinery. I pasted the paper template onto a heavier strathmore stock and started doing the final fitting. I don't know why, but I found it necessary to make relief cuts in this bulkhead in SU. The guns were impacting it. I don't know the actual dimension of this bulkhead in the real ship. Since so many of my measurements are estimates I could have some stacking errors that crept in with the guns themselves. Just because they look great doesn't mean they're exactly scaled.
I added some height to my original drawing so it matched the height of the pan deck's walls. I then glued the strathmore template onto the 0.040" styrene.


I had to keep adjusting the width and positioning to get it just right. I went back and measured my full-size SU drawing to capture the distance from the front of the shell to the bulkhead and then divided by 72 to get the actual number. My positioning was very close.
Another critical dimension was the positioning of the slots that the B-end hydraulics drive shaft that must align to the holes in the gear heads. It took a bit of fiddling to get this one right.

I used a square to hold it in position while I started with solvent cement to tack it in place.

After the solvent cement set a bit, I went back and sealed all the edges with thick CA and accelerator. I will attach the B-ends AFTER all the pan deck is painted.
With the front bulkhead done, I crafted the center bulkhead that lies above and between the two gear heads. I had to notch this out just like the tranverse bulkhead to clear the gun, especially when they elevate and all the recoil mechanism on the bottom swings down. I'm only elevating the left gun, but the bulkheads have to look like the others could too.
This piece also stabilizes the flimsy area in front as a result of all the cutaway work. Again, started with Strathmore, then transferred to styrene when it was right. This shows the Strathmore.

When the fit was right, I made the real one. In this case, I radiused both cut outs. I then added some 0.020" X .125" styrene strip to act as the typical welded webbing on all the perforations in all the bulkheads throughout the entire ship. This was fun, good old, old school scratch-building.

I did a final test fit, and liked it.

Now I had a decision to make. I couldn't glue this in if the training gear wasn't installed since I couldn't get the training gear in with this bulkhead in place. But I wanted the bulkheads to be all glued in before painting. I bit the bullet and prime painted the gear head, and installed it with thin CA. I then final glued the front bulkhead in place with solvent and CA as before. I then added some reinforcing blocks around that front butt joint. I didn't want it breaking loose. These are behind the wall and won't be visible through the cutaway. I'll just have do some fancy brush painting to do the gear head.
I put the webbing on the center buikhead so I had to put it on the transverse one. Finicky, but fun.

With everything glued in place, it's now ready for paint.

Here's the view through the cutaway.

I did one more print job.
I was trying to figure out how to support the model on the display base. I was going to machine a part out of brass, but then said... "Draw it and print it". It's going to be below the base underneath in the circuitry box. The leads for the LEDs will come out of the hollow CPVC tube below the base. The screw holes are just place holders since I don't know what hardware I'll be actually using.
The printed through hole is a couple of thousandths under 5/8" so the copper tube wouldn't get all the way through. i turned it into a ream by grinding a slice in the tube's edge and a cutting lip and by twisting it, let it open the hole up enough to pass it. It worked. And the plastic tube is a nice tight slip fit. This is the bottom that will be in the box.

And this is the mounting surface that will go up against the base box surface. I notice a discontinuity on the one of the screw bosses. The radius didn't form a solid around that one. I hope it will work as it is.

I did a quick estimate of the center column height and cut it off with my big chop saw. I put the stack together just for fun. It does not penetrate the electric deck. It sits in a socket, but as I'm writing this I realize that I will need to find a way to get all the wiring from the this deck, the pan deck and the gun house through that tube and down to the base. There's a lot of bulkheads that aren't going to have cutaways or be transparent so it shouldn't be a problem. Just have to keep it in mind. It's why doing all this journaling actually helps me produce a better model.

I don't actually know the wood thickness that my friend is going to use so the spacing below the powder flat is just an estimate. The actual boss diameter is .79" which is bigger than 3/4" and I don't know of a drill that size. I needed to give the walls some meat to support the tubing and the tube is 5/8". The boss is supporting the tube, not the base so the hole can be any size bigger that the boss.
Tomorrow I will tackle the electric deck. It too is going to have some scratch-built add-on small bulkheads.

Builder 2010 said:

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.
View attachment 669065

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. View attachment 669066

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.
View attachment 669067

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.

View attachment 669068

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.View attachment 669069
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.View attachment 669070Right 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.


View attachment 669152The 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.
View attachment 669154

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

Click to expand...

Amazing work. I'm envious of your talent and attention to detail. Amazing is a word that I use here…just because…because there's so much amazing people here on this site.

Far Out Man!
has this been used yet?

Thanks guys! It truly is an amazing site!

More work proceeds on the pan deck. Again using Strathmore art paper, I made three templates for the fore and aft partitiions. I then transferred to styrene, final shaped them and started to install. I'm not going to use transparent styrene. I have to use Med/thick CA to glue the styrene to the base UV resin and solvent cements have no effect on the UV resin. That means CA and it can cloud clear styrene. instead I'm just going to continue using the cutaways that were started with the outer shell.

I made another critical decision: I was originally going to apply the prototype's method of having the partitions go straight down from the turret ceiling to the pan deck. This would have meant inserting the entire girder from the top and still be able to glue it in place at the bottom of the pan deck. That was bad enough, But the partitions sit ON TOP of the trunnion caps, meaning the guns would have to be installed first. The guns completely block access to the pan deck! This simply wouldn't work.

Instead, I'm splitting the partitions with the lower pan-deck portion being measured and installed completely, then painted and have all the appratus installed. The gun house base structure gets painted, and all the apparatus installed. Then the guns go in with their trunnion caps and finally, the gun house partitions get glued to the flanks of the gun girders. I suspect that due to the spacing variations, the upper and lower pieces may not align perfectly, but they will be very hard to see and it's the only way I can envision getting it together.

This shows the split template. These were originally a single sheet. Notice how the partition is cut to go on top of the trunnion.



I make the template larger than needed and then creep up to the correct fit. It is critical that the pan deck apparatus fits between these partitions. The elevating gear goes in the same space as the gun pit and the training B-end goes in the in-between spaces. My gun pit spacing and even the gun girders themselve ARE NOT as accurate as I would llke and the spacing has some variability in it. But the appratus has to fit so I'm using them as the final positioning guide.



I made all three templates first. Two of these, the middle ones, will be in pairs. The outer one is on the back wall, but not in front since it would block the cutaway.



The port side partition needed some more fiddling to have it clear the reinforcing girder that encircles half of the pan deck base. This too was cut out and shaped while still using Strathmore. Paper is much cheaper than scrapping badly cut styrene.



This piece was then transferred to styrene, solvent glued to the other styrene and bonded to the base using accelerator and medium CA. After installation I wanted to add these side bulkheads. There appears to be lightening/access ports in them which I cut, first in paper and then in styrene. While they would have had webbing, the radius is too tight and the styrene would split under action of the solvent cement. So I left it off here. These could have been 3D printed, but I had no idea of how big they would be until building it. This is the paper template.



Here it is with the styrene. The tapered sides of the drum certainly make it interesting.



Here's a view showing positioning of some of the apparatus with the next partition set in place. I haven't cut the cutaway on this so nothing is glued here. On my original plans I had another tranverse builkhead going across the back, but after careful review of the plan I realize that this dotted line was something that was below the deck. I also am not sure if there's a passage across the back from one pit to the other. I highly doubt it since this violates the whole philosophy of segregating anythng that could pass fire from one area to the other.

There would be one more side bulkhead spacer, in the fore part of that chamber, but it would be right in the cutaway. I may pit it in and cut it away too. That strange object that's on the bottom of this image is my lovely Browne and Sharpe small combination square viewed end-on. I use it during the gluing to help keep things plumb.

Your decisions seem to make a lot of sense.

And yes, this is quite the site!
All looking to pick up itty bits we can use in our own decision making!

Thanks guys!

Didn't have much time in the shop... was buying stuff for the Hawaii trip. That said, did get some more stuff done.

The pan deck partitioning is almost finished.

I was able to position all of them so the apparatus fit, but the variances I introduced in the gun girder land width definitely knocks the alignment off between the bottom and top partition halves. I was so concerned to get the gun spaces centered and correct width that I ignored the fact the the pieces in between the spaces were no longer equal. Forest and trees syndrome. Can't do anything about it. That ship has left the dry dock. It will almost impossible to visualize these erros in the finished model since the guns and the aft gun compartment parts hide almost all the happenings in the pan deck below. That's why the cutaway is so critical. Here's what's done so far. The apparatus is just there for spacing.

The relief cuts on the top of the middle two partitiions is for the piece of 0.040" styrene that I installed to give a positive stop to the middle gun compartment print. It protrudes into the pan deck space and the notches let the pan deck seat evenly all around.



I put on the gun house base and a gun to see what the view will be looking straight through. This is how viewers will see it. While it seems very light in there now... so why worry about LEDs, when all the stuff is on top it will get much darker and lighting will be necessary.



Painting all this will be fun...especially masking the walls so I can airbrush the deck surfaces. i thinking of outlining the cut edges of the cutaways with red or green to highlight them... thoughts?

The elevating box is the wrong hand for the right gun so the elevating screw is not engaged in it. Doesn't matter. it was just to get an idea of view.

Have a great, and for US readers, happy and safe Labor Day weekend!

If possible just the cut edge in green? That may be what you mean.
Mahhhvelous work.

Yup! That's exactly what I mean… Green it is!

Tend to agree with Burt on Red. think about cutaway engine blocks, in my minds eye I see the edges painted in red.

Okay… I'm going red. That's the trouble of putting stuff out for a vote. You get a lot of opinions.

Even though it's Labor Day I did get some shop time. Finished up the Pan Deck partitions with the small cut down one in front. I cleaned up the edges a bit more and it's waiting for paint. LED wiring will come down behind one of the back bulkheads out of sight.



I started working on the electric deck and almost got it ready for paint too. I glued in that complex mid-section print with the training system and one of the projectile hoist power packs. I also had to do the cutaway on the this part's port side wall so you can see into it. I used the Dremel with a carbide router to make the cuts. Resin doesn't melt like styrene and works well with burrs and other high rpm cutters. Styrene melts so fast it just gums up the tools.

I did the fill-in bit like I did with the projectile flats to close the rectangular holes for the old design powder trunks.



There are six, small bulkheads that fill the fore space where the training pinions are. They reinforce this critical bit of turret infrastructure. This took most of the afternoon. Each had to be hand measured and cut since there are some slight variations from side to side. What made it more challenging was the training pinions had to slip between nos. 2 & 3 and 4 & 5. When I first assembled them to look nice, they didn't fit and I had to start ripping them out. Since it's a styrene/UV Resin interface I had to use CA. This is good since the styrene has a so-so bond with the CA and I was able to rip stuff out (more than once), sand off the old CA and reglue until I got it right.



The Fit is quite tight. And then I had to put the pan deck on top with both pinions in their respective holes in the training gear heads, and then try and fit it together with the pinions not being cocked in one direction or another. This entailed more ripping out and refitting.



I finally got all six in and spaced so the pan deck worked. Then I had to go back and relieve all the slight misalignments with all these printed parts. I have reinforcing ribs under the pan deck with corresponding slots in the electric deck walls to accept them. I'm sure this is not prototypical, but I needed the ribs to reduce warpage of the big, flat pan deck base. They did the job, but they're a pain in the butt to get to fit into the electric deck slots. I almost got it done when it was quitting time. My daughter and son in law were coming over for burgers. They're now empty nesters with my youngest grandson starting as a freshman at Washington University of St. Louis in engineering and my oldest grandson entering his senior year at University of Illinois engineering.

Here's the completed bulkhead scheme. As you can see by the above image, you realy can't see any of it. What it did do was enable me to pull in the electric walls so they're true vertical. That large cut out area for the pinions left the wall unstable and it was warping out a bit. I put some filler pieces in the middle bulkheads to hold their spacing since it was so critical for the pinion fit.



Once I get all the inpingement areas cleared out and get the pan deck to drop flat onto the electric deck, I will be done with the electric deck and it too is ready for paint. All the other apparatus will go in AFTER paint. Actually, lighting goes in before paint on all the decks. I mask the tiny LEDs, but the paint hides the surface mount copper conductive tape. There will be a lot of non-viewable areas on this deck also which will make it easy to get the lighting wiring down to the central column with terminates under the electric deck.

Assembly progress is moving along pretty well and it may not take as long as I was anticipating to get it built. We'll see. There will always be more surprises.

This is the illustration I'm going to include in the display along with the callout list. When I first developed the list I went into MUCH more detail, but realized it would bore people to death. Museum display designs usually have three levels of explanation. Level one is for the person who's breezing through and just looks at things that catch their eye. The model does that. Level two is broad head type that gives a quick view of what's what, and Level Three can actually get into paragrph text for those who want to stop and read. It was the level three depth that I'm still not sure about.



Here's the text to go with the callouts. Should it be more? Less? Just right? Feedback is requested.