Sunrise Division

SUNRISE DIVISION

The Sunrise Division continues to work on their modular layout to prepare for display at the next Rocky Mountain Toy Train Show, November 29-30, at the Denver Merchandise Mart.  Our current emphasis is on streets and roadways and commercial and industrial buildings in the town sections of the layout.

For each monthly meeting, one of our members presents a clinic on some aspect of model railroading.  For our October meeting, Doug Semon presented a clinic on 3D printing.   Some of us wondered what 3D printing had to do with model railroading, but it quickly became evident. Such printers would obviously be quite useful for making complicated parts for scratchbuilding, possibly replacing older casting techniques 

He began his clinic with a PowerPoint presentation.  He selected a control panel example for his ‘project’.  For his panel he wanted to mount some square push button toggles on his control panel, and to provide a neat appearance.  To accomplish this, he created bezels to frame the toggles.  Making them by hand proved to be too laborious, so he used a 3D printer instead.  

Next he described the software and steps required to prepare the 3D program:

1. Design the part

2. Save the raw 3D design

3. Import the design

4. Scale the part

5. Adjust the print parameters

6. Save the design on a memory chip

7. Insert the memory card into the printer and print

He demonstrated the software design process for the bezels in PowerPoint.  The software is similar to a CAD program, but less complicated.  If the part to be made is more complicated, he showed a 3D scanner that may be used to scan the design and create the program.

Doug's 3D printer

Finally Doug discussed the economics.  Low-end printers, he explained, can currently be obtained for about $300 - but for quality work, he didn’t recommend those.  His printer currently retails for about $2500. For most of us, that would be well beyond our budgets, unless we are planning to make a lot of parts or want to gain experience. However, the price will probably drop significantly in the near future as the printers gain popularity.

The printer works, not by printing as we think of it, but by extruding a stream of molten plastic in layers.  Two types of plastic are used: ABS (such as Plastruct) or a plastic made from corn starch.  The plastic is extruded onto a glass bed that Doug covered with blue painter’s tape to avoid the plastic part sticking to the bed.  The tape is also pricey, but he explained that one roll will probably last a lifetime.

The printer at work. The reel on the right side contains the plastic feed stock that passes through the white tube to the ‘print head’.

Before starting, the print head must heat up for about five minutes and Doug cautioned us not to touch it.  For this demonstration he copied six bezels onto the design so he could make six parts at a time.  It then took about fifteen minutes to “print” the six bezels.  Doug used orange feedstock for the demonstration, but other colors are also available.  He suggested that if anyone can produce a design, it may be possible to have it commercially produced at a nominal cost.   Candidate parts might include car sides, ends, roofs and underframes.  It would only be a small step to turn Doug’s bezels into structure windows and doors for parts that are not commercially available.  This might include an entire building including walls and roofs.

3D printing opens an entirely new technique for making parts and its application is only limited by our imaginations.

The printer after project completion showing three completed bezels on the bed.

Stewart Jones

Division Secretary