APA project

[Fliger747]

Today's design project: To make 40 mm ready storage racks for the fwd quad 40 mm Bofors. Making these in four segments for the tub. We will see how this goes!

[Fliger747]

I made 3/4 of the circle of 40 mm storage racks for the fwd Bofors. Tomorrow I'll see how they fit and if they need to be adjusted, The 4th segment has a gap to allow access into the tub and will be different. The would be easier if the Bofors wasn't already installed. As an aside the 1:192 inclined ladders for Alaska and Missouri printed nicely vertically.

Cheers: Tom

[Fliger747]

1:192 Skeeter Bits, sky lookouts, inclined ladders.

Three of the four 40mm ammunition rings for the forward 40 mm mount.

[BB62vet]

Tom,

You're really going to town on the parts!!! Well done - the ammo stg. racks looks great! Are you using the Phrozen Model Gray Resin or...???

I got a photo w/dimensions on parts of the 3" mount from Willie - hope to work on a jig later this evening. Waiting for paint on my new slide-out surface to dry.

Hank

[Fliger747]

Thanks Hank! Right now I am printing the last segment of the ammunition racks. There is a gap where the tub access is just to Starboard of the MK 51 director (it's a climb over). So I split a ring section into two parts. What surprised me was how substantial the curved racks are!

Tom

[Fliger747]

Those segments printed nicely. So next project is making ammo rings for the fwd 40 mm twins. As it turns out it works better making these in two segments. Inconveniently the aft twin tubs are a different size! Once I got the idea of how to do this, it's not too bad. Being the year 2020 one can't expect things to continue in a smooth manner for extended periods of time. On my Floortop Computer the Chitubox (slicer) went wonky and loads the pieces half submerged and won't platform. Fortunately I also have it on my laptop and was able to slice and hopefully print OK. These needed a slit anyway as the 40 mm is already installed in the smallish tub.

Tom

[Fliger747]

Today I airbrushed a plethora of small (itty bitty) parts and installed the 40 mm ammo racks on the tubs. Downloaded and reinstalled the latest version of the slicer, hoping it works OK. So now to look through photos to see where some of these cleats and whatnot can be installed!

Tom

[Fliger747]

Today I printed circular rail for the foremast SG radar platform, which looks very nice. At the same time I also printed rail to surround the inclined ladders as they emerge on the top bridge deck. However I fat fingered the dimensions so am printing some new ones. The Aft mainmast radar also has a circular rail, however I will need to re design this as it will need to be split as the large search radar is too large to slip the rail over in one piece. For the 1:120 scale the printed rail is very nice, perhaps better than PE with a more three dimensional appearance and not overscale.

Cheers: Tom

[Fliger747]

Fwd Mast platform rail ring. The one for the aft mast printing now has a split for installation.

[BB62vet]

Tom,

That looks excellent - wish my handmade railing for the Mk. 56 Director platform had come out as nice. You're moving right along with the 3D design - kudos!

Hank

[Fliger747]

Hank:

Send me the dimensions and I'll send you a file.

Tom

[DrPR]

Tom,

How tough are those hand rails? Are there non-brittle resins?

The reason I ask is that when I start on my 1:96 Oklahoma City I will have miles of hand rails to build. The dimensions of the tubes were 1.25" diameter to 0.75" diameter. That translates to 0.013" (0.33 mm) to 0.008" (0.2 mm) diameter at 1:96.

I have brass wire for the rails, but I have been trying to figure out how to drill an 0.008" hole in a 0.013" wire. Tricky! However, if I could 3D print the rails life would be a lot simpler! But I don't want to mess with thin parts like that if they are brittle and will break at the slightest touch.

Phil

[Fliger747]

Phil:

These are quite flexible and reasonably tough. It's their flexibility that makes such an airy structure survivable. The flexibility also makes the installation a bit more tricky. The 1:192 inclined ladders that I retrofitted for Alaska and Missouri seem tough enough. In some cases in the smaller scales a slight overscale of hand rails etc seems visually acceptable. I'll be able to comment more as I gain experience.

Tom

[BB62vet]

Hank:
Send me the dimensions and I'll send you a file.
Tom

Thanks, Tom - I'll get a 2D drawing to you today on that particular circular handrail. I may try to get back to DSM today and start with the vent covers - complete redo in metric this time. But, I will save your last .stl and .phz file you sent me as back up.

My guess is that the handrails were 1" dia. (actual), so in 1/144 scale these would be 0.008" (rounded) or 0.176 (0.18)mm. You comment regarding oversizing is completely acceptable and logical. Right now, my handrails are 0.76mm dia. which is a bit large. The stanchions are wider and need thinning down, etc.

I will locate the postions of stanchions - there is also a 5mm gap in the back for the vertical ladder.

Hank

[Fliger747]

Hank:

File on it's way to you. Always possible that some adjustment will be necessary!

Tom

[Fliger747]

Some more life line experiments. The area on the boat deck where the paravanes were located appeared to have removable stanchions connected with chain.

[Fliger747]

Phil:

I have had decent luck making rails down to .3 mm which is a little over 1" at your scale. .5 mm is much more substantial. Pascal with his experience would be much more able to comment with authority.

Tom

[DrPR]

Hank,

On US Navy ships WWII to post Vietnam the normal hand rails were composed of:

1. The top rail was 1 inch diameter pipe.

2. The lower two rails were 3/4 inch pipe.

3. The vertical stanchions/posts were 1 1/4 inch pipe.

Note: These are INSIDE dimensions (ID). Outside dimensions (OD) are:

1" ID = 1.315" OD
3/4" ID = 1.050" OD
1 1/4" ID = 1.660" OD

Normal spacing between the horizontal pipes was 12" between the top two pipes and 15" between the lower pipe and the deck.

Stanchions with caps were normally 38" high from the deck. The top pipe rail centerline was 2" below the top/cap, was notched to fit to the vertical pipe, and welded to the side of the vertical pipe.

Stanchions that did not rise above the top rail were 42" tall from the deck to the centerline of the top pipe rail. They were notched and the top rail was welded into the notch.

Stanchions were normally welded to the deck and to the 3" high coaming around the superstructure decks. However, some railing stanchions were attached to the sides of the bulkheads instead of being welded to the deck. In these cases the stanchions were 1" longer and were welded to the outside of the coaming and superstructure side, with the top rail centerline 42" above the deck.

NOTE: Some rails were not "normal" and might have only two horizontal rails (or 4), or they were made of larger diameter pipes. But most of the rails around the superstructure had the dimensions given above.

Hope this is useful.

Phil

[Fliger747]

Good info as always!

[BB62vet]

Phil,

I certainly appreciate it (your handrail info above)!! Was not aware of the actual details. This will help with 3D design of handrail parts for sure! I'm printing out your info so I can pin it to my bulletin board.

Info like this is sometimes hard to find, esp. if you don't have available design criteria from shipyards.

Thanks,

Hank