The Ship Model Forum

[b]A set of four Mk.8 torpedo warhead inserts is now available in [color=#0000FF]1/48 scale[/color].[/b]

The larger scale permits the addition of end-cap retainer plate detail. On real PT boats, the end-cap retainer plate was fabricated and installed in the field to prevent the torpedo from falling out of the tube in rough seas. Surely, a live torpedo falling out of the tube was a significant emotional event for the PT boat's crew.

In addition to acrylic plastic, these inserts are also available in several finishes of real stainless steel (including bronze, gold and black stainless steel) for those who desire a true metallic finish.

[b]A set of four, 3D-printed Bliss-Leavitt [color=#0000FF]Mk.8 torpedo warhead inserts[/color] is also available.[/b] The Mk.8 torpedo was used by PT boats early in the war, among other USN and RN vessels. These domed warhead inserts are perfectly scaled to fit 3D-printed Mk.18 Torpedo Tubes, available separately. They are not suitable for destroyer torpedo mounts.

1/72 scale: http://www.shapeways.com/product/55HCHSQ69/1-72-mk-8-torpedo-dummy-warheads-for-pt-boats?optionId=60529123

[attachment=0]1-72 Mk.8 Torpedo Warhead Inserts for PT Boats.png[/attachment]

[b]Model Monkey is very happy to announce that designs for highly accurate, 3D-printed [color=#0000FF]Mk.18 Torpedo Tubes[/color][/b] have passed Shapeways' design analysis software and are ready for purchase. They are available in 1/48 scale now (for Bluejacket Shipcrafters and Merit kits) and 1/72 scale (for Revell) and will be in 1/32 scale (for Lindberg) shortly.

They come in two sets of two tubes, one pair of forward tubes and one pair of aft tubes (their forward carriage slides are differently shaped). Port-side tubes are also slightly different in detail than starboard tubes - their breech door hinges are inboard, for example. Each tube model consists of three parts: the tube itself, the aft turntable, and the forward carriage slide.

1/72 forward tubes: http://www.shapeways.com/product/MEESJMRSF/1-72-mk-18-fwd-torpedo-tubes-for-pt-boats?key=5b5b523e4e9ac608fdccb81e02d04e9b
1/72 aft tubes: http://www.shapeways.com/product/MAWVJ2DPS/1-72-mk-18-aft-torpedo-tubes-for-pt-boats?optionId=60528677
1/48 forward tubes: http://www.shapeways.com/product/FGCDMUVWR/1-48-mk-18-fwd-torpedo-tubes-for-pt-boats
1/48 aft tubes: http://www.shapeways.com/product/53Q863MUA/1-48-mk-18-aft-torpedo-tubes-for-pt-boats

[attachment=9]1-48 Mk.18 Torpedo Tube PT Boats.forward.b.png[/attachment]
[attachment=8]1-48 Mk..18 Torpedo Tubes.aft.a.png[/attachment]
In addition to "Frosted Detail" acrylic plastic, in 1/48 scale, these models can be printed in two finishes of durable [b]stainless steel[/b], recommended for radio control use.

This type of torpedo tube was mounted to many early-World War Two US Navy PT boats such as the famous PT-109 commanded by then-Lieutenant John F. Kennedy. Mk.18 Torpedo Tubes were used early in the war until replaced by roll-off racks for the more reliable and predictable aircraft-type Mk.13 torpedoes. A good reference for various PT boats can be found on NavSource: http://www.navsource.org/archives/12/05idx.htm

[b]Features: [/b]
- accurately scaled from scans of original Electric Boat Company manufacturer's blueprints dated 3 December 1942
- details confirmed from careful study of period photographs
- accurately depicts the different features of the port tube and the starboard tube
- separate aft turntable and forward carriage slide permitting the modeler to display the tubes in their stowed position or rotated outward 8.5 degrees for firing. Tubes may also be displayed dismounted
- detailed concave breech door with stiffener details
- accurate, detailed, tube-top firing combustion chamber
- accurate breach door hinge
- exterior stiffener rings properly sized and located
- accurately shaped and located training gear
- bolt heads accurately scaled in their proper position, randomly turned for realism
- rivet detail
- subtle weld line detail
- tube hollow through to the breech door
- training gear handle, combustion chamber handles, clasps and exterior tubular brace omitted (too thin to print)

[b]Thanks to David Waples for providing high-quality scans of original blueprints.[/b]

[b]Some part cleanup will be necessary.[/b] During the 3D printing process, a waxy substance is used to support certain part features. Although the parts are cleaned by Shapeways afterwards, some waxy residue may remain. It can be safely removed with water and a mild aqueous detergent like [b]"Dawn" dishwashing detergent, baby shampoo (no conditioner)[/b], or [b]"Simple Green"[/b] using an old, soft toothbrush, Q-tips or pipe cleaners. Customers report that [b]"Bestine"[/b] and [b]"Goo Gone"[/b] also work well.

During the printing process, liquid resin is cured by ultraviolet light. Microscopic bits of resin may remain uncured. [b]Let your parts sit in direct sunlight for a few hours to fully cure the resin.[/b] After your parts have fully cured, careful use of an inexpensive [b]"air eraser"[/b] emitting common household baking soda can help smooth surfaces or remove unwanted frost without harming detail prior to painting. An air eraser, similar to an airbrush but much cheaper, can be found on Amazon.com. Models by Harbor Freight and Paasche are popular.

[b]Water-based acrylic paints meant for plastics[/b] is strongly recommended. Other paints, especially enamels, may not cure on Frosted Detail 3D-printed plastics.

[b]� Model Monkey Book and Hobby. This 3D-printed item may not be copied or recast.[/b]