One of the most vexing parts to make for many large scale model ships is the classic “cowl vent”. The things defy verbal description, but you merely need to look at a picture to realize that a correctly shaped vent is a bear to make. In smaller scales, they can be made in solid, and are also readily available from model ship fittings suppliers. But the larger scale parts need to be hollow, and that’s the tough part.
Some will suggest that they can be made in the original fashion, fabricated up from bits of sheet material… but I have yet to see anyone make several good looking parts with such an approach. And while some prototype vents actually are built up in segments, many are hammered into smooth forms to hide the segmentation… and that’s more than I’m willing to do.
Then, even if you succeed in making a fair master part, the cored interior makes replication by resin casting techniques all the more difficult.
As an alternative to all this grief, I’m making my “3D printed” cowls available.
What is 3D Printing?
For those unfamiliar “rapid prototyping”, the process can be quite amazing… actually, I am familiar with it, and I still find it amazing. There exists a number of available process, but all start with a 3D CAD model of a part. The part model is then sliced into layers, which are “printed” one at a time on top of each other to build up a solid form. The printing process involves a laser tracing out the shape onto a thin layer of plastic. The laser’s energy sometimes solidifies a liquid polymer, or in other processes, fuses powdered plastic into a solid.
Moreover, several enterprising small companies make the process available to anyone submitting a model. The best one that I have found is Shapeways in the Netherlands, who have created an easy to use e-commerce site at http://www.shapeways.com/.
You can read about my experience with Shapeways and another 3D printer at this RC Groups posting.
Pat’s Cowl Vents
So I made a model in 3D CAD of the classic ship’s cowl vent, and scaled it to several sizes. The models can be found at Shapeways by using this link to my “shop” there:
My vents might be best suited for modelers needing several large parts; the largest listed uses a 3/4″ (19mm) tube, with a 1-1/2″ (38mm) diameter cowl. The smaller vents might be a bit clunky due to the minimum wall thickness I needed to apply. For smaller vents, commercially available cast parts should also be looked at. But you’re not likely to find anything like the larger parts I offer here.
Shapeways offers a selection of materials (even sintered metal!). Feel free to select anything that looks good to you… but I recommend the “White Detail” plastic for best surface finish… “White Strong & Flexible” is lower cost, but may require a bit more hand finishing.
Since the material is laid down in layers, parts will have a stratified look on some surfaces. You will need to sand down and/or fill the surfaces to your own satisfaction.
Shapeways handles the orders. You need to sign up on their site (easy), and order directly from them. They accept Paypal, and ship quickly; I’ve received parts in the USA within a week. Only one hitch: They have a US$25 minimum order. VAT will apply to European buyers.
Use the table below to select the size you need, then find that part at the Shapeways site.
Let me know if you have any questions or feedback on the parts. Also note that I can scale the model to any desired size.