Re: Katten Koffietafel Spoorweg
« Reply #15 on: March 20, 2019, 12:01:39 am »
Adventures in Construction
The switching yard depends on troughs in the middle of two of the spurs that allow wagons to coast to neutral positions without locomotive support. This means that the underlying roadbed must be fabricated with accuracy. There will be adjustable feet and a spirit bubble to ensure proper leveling.

I considered a flat switch yard but could not make the automation work without inclines and troughs.

Kudos to AnyRail: I could not have completed the layout without AR's slope tools.

AnyRail can export a variety of 3D files in various forms. The two that appear most useful are .STL and .STP formats. .STL files are used, typically, for 3D additive printing, where objects are built by material deposition. .STP files, in contrast, are used, typically, for 3D subtractive printing, where objects are built by computer numeric control milling. Additive construction is good for producing small parts. CNC milling is usually a requirement when dimensions greater than 20cm are involved.

I got some practice with additive printing by visiting the Boston Public Library, where patrons can print (at no cost) using .STL files. There, I made a Beatles Yellow Submarine (see attached image) and found that .STL files are generally unit-free: if you don't constrain the units to be, say, centimeters, you can end up with a life-sized submarine!

To make KatPunt, I visited more than several businesses but found only a few that are active. 3D printing may be "The Future" but it is not really yet "here." More than one firm I checked out was no more than an empty room. Did they have capabilities and have since folded ... or are they merely hopes and dreams? I have provided a list, below, of businesses that I actually saw as operational.

A highlight was that I was able to watch milling operations at a General Electric facility and gleefully saw an incredible technological ballet as machines churned through billets of aluminum, steel, and even titanium. Also, I found a great restaurant in Boston.

AnyRail exports 3D files but such files seem to have a deficiency: they create objects rather than roadbeds. Refer to the second image I've attached; it shows that portions of the layout have both the rail and ties described. If there's a means to prevent this, I have not found it. As can be seen from the image, the .STL file was produced with only the Track category selected. I did try with the Ground category selected (only and in conjunction with Track) but still got rails and ties. There are a variety of editors for .STL and .STP files, some freely available from printing vendors (see eMachineShop). I'm just starting to use these applications.

Even with CNC milling, it is best to fabricate in smaller elements. I intend to use closed cell polyvinyl chloride (PVC) foam (often branded Azek) because it is dimensionally stable and resistant to deterioration due to humidity and volatility. It is somewhat difficult (even dangerous) to carve, but it accepts acrylic glue (for grass) and paint well.

I will report my further adventures here.