Introduction: 3D Printed Town : Lac-Mégantic

About: Software Engineer & Maker

I've 3D Printed my grandmother's hometown as a mother's day gift.

The town is Lac-Mégantic located in Québec, Canada. You may have heard of it because of the rail disaster in July 2013 which claimed 47 lives and destroyed more than 40 buildings downtown.

My grandmother and most of my extended family still live in the area, which is now unrecognizable after the decontamination and rebuilding of the affected zone. So I've decided to recreate how Lac-Mégantic used to be, using a 3D Printer and paint. The result is a 8x6 inch (1:3000 scale) 3D map tile that can be placed horizontally on a shelf or hung vertically on a wall, in a frame.

Since there was a lot of interest on these Redditthreads, I've created this step-by-step Instructables on how I modeled and printed this town. It can inspire you on how to achieve a similar result for your own city.

Things needed for this project:

  • SketchUp
  • 3D Printer
  • White PLA filament
  • Acrylic Paint

Step 1: SketchUp

I've used SketchUp 2016 to model 100% the town from scratch.

The plugin Solid Inspector² is really useful to find 3D errors such as face holes, surface borders, internal faces, or stray edges. They are not fatal but would make the slicing process difficult for printing.

Once the mesh is clear of bugs, I use the STL file Exporter plugin to export STL files to a slicing software.

Step 2: Google Maps & Google Earth

I've used a mix of Google Maps and Google Earth to trace the outlines of the lake, streets, city blocks in 2D from a top-down view. I then traced the individual buildings from the same view for extruding later.

To do that, I take a screenshot of the map and import the image in SketchUp using File -> Import -> .PNG (Use As Image). I then scale it on the XY axis as a reference image to draw the lines on top it.

Step 3: Google Street View

For smaller cities that don't have a 3D mode in Google Earth, such as Lac-Mégantic, Google Street View is useful to get a sense of the shape and dimensions of the buildings. Luckily, there is a Street View available made in June 2013, a few weeks before the train derailment. I used it to draw the general shapes in 3D of the various buildings around Lac-Mégantic.

Step 4: Groups

The easiest way to model a city is to make each city block into an individual SketchUp Group. This way you can move its boundaries around to shape the streets and debug each block individually instead of the whole model. The base is another separate group that can be adjusted downward to control the thickness of the resulting printed tile.

Step 5: Trees

To model trees, I draw cones, they are simple, low-poly, and easy to print and paint.

Simply draw a 24-sides circle on the ground, then extrude it as a cylinder at the desired height. Then scale down the top circle horizontally around its center.

Step 6: Exporting STL

I've attached the STL model for Lac-Mégantic, so you can print it too.

You have to scale it down to fit on your 3D Printer's build platform.

Step 7: Slicing

I use Autodesk Print Studio to slice the model and export the printable file.

I first import the STL file into Print Studio, then rotate, center, and scale it down to fit the build platform for a dimension of approximatively 8x6 inch. If there are any bugs with the model, I auto-repair them. This model doesn't require any support.

I hit the Print preview to visualize the layers that will be printed.

The print time for this build is around 10 hours.
The print volume is around 63cm³ or 40 meters (131 feet) of filament.

Here are the 3D Printer settings I use for my Dremel Idea Builder using 1.75mm PLA filament:

  • Layer height: 0.15mm
  • Number of shells: 2
  • Sparse infill density: 15%
  • Sparse infill pattern: Rectilinear
  • Travel speed: 100mm/s
  • Sparse infill speed: 80mm/s
  • Extruder temperature: 220C
  • Extruder retract length: 1.0mm

Step 8: 3D Printing

First step of 3D Printing is always to level the build platform to make sure the extruder is right above it, with the right pressure to execute the first layer efficiently.

I use a bit of hairspray on the build platform to make sure the first layer will adhere correctly and avoid wrapping at the corners.

I use a spool of 1.75mm white PLA filament suspended directly above the 3D Printer.

After an hour, when the first 5 or 6 layers are printed correctly without any wrapping at the corners, you can relax and let it print for another 9 hours :) If you live somewhere that has frequent power interruptions, a UPS is recommended to keep the printing going after a brown out.

Step 9: Polishing

When the printing is done, detach the tile carefully from the build platform using a flat palette or painting knife.

If the tile has some wrapping at its corners and is not totally flat, you can submerge it in 60C water for a second, then remove it and flatten it on a hard surface. PLA gets malleable around 60C for fine adjustments.

I use a Dremel micro rotary tool to remove any imperfections on the plastic such as stringing, oozing, blobs, zits, scars, or anything you want to remove.

Step 10: Acrylic Painting

Once the surface is smooth, it's ready for paint!

For this type of painting, I recommend pale colors, so dilute your acrylic paints in white.

I started with the water (blue), then the lawn and trees (green), then the streets (grey), then various colors for the buildings. Use a fine paint brush for this type of work.

Step 11: Done!

It's done!

To display it, you can insert it in a picture frame to be hung on the wall. Or if you want to display it horizontally, you could glue it on top of a plexiglass tile.

Post any questions in the comments.

To see more of my 3D Printing projects

3D Printing Contest 2016

Participated in the
3D Printing Contest 2016