QGis from OS Contours to two coloured contour DXF file

  1. In QGis copy the area required using the selection tool.
  2. Create a new project and Paste in the contours.
  3. Use Documents/Mapping/QGis Projects/scale_conversion.numbers to predict the model size based on the depth of the material.
  4. select the contour layer on the left, right click and select properties
  5. select Style and then load previously saved style file “two_colour_contours.qml” (or copy this one, top box needs to be set to rule-based)
  6. Screen Shot 2014-10-24 at 23.41.10
  7. apply the style and the contours should be blue and green.Screen Shot 2014-10-24 at 23.28.48
  8. if below sea-level (low water line) contours appear then it is necessary to remove them by clicking the attribute table button (towards right hand end of top bar). Order by SUB_TYPE and select the low water line items, click the pencil to edit and then click the delete button.
  9. Click Project->DXF Export.  Save with symbology, don’t forget to highlight the item to be saved.

SRTM Contours

contours of the world available from the NASA shuttle mission.



See also DEM data at  http://www.viewfinderpanoramas.org/Coverage%20map%20viewfinderpanoramas_org3.htm


A high quality DEM from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument of the Terra satellite is also freely available for 99% of the globe, and represents elevation at 30 meter resolution. A similarly high resolution was previously only available for the United States territory under the Shuttle Radar Topography Mission (SRTM) data, while most of the rest of the planet was only covered in a 3 arc-second resolution (around 90 meters).

https://tandemx-science.dlr.de/ high res earth mapping

or use OS :



to convert os data to sketchup:


online mapping  :

http://www.openstreetmap.org/#map=14/57.7987/-5.2579&layers=C (roughish 10m contours from opencyclemap)

http://www.arcgis.com/home/webmap/viewer.html?useExisting=1&layers=30e5fe3149c34df1ba922e6f5bbf808f (smooth 25m contours)



http://www.qgis.org/en/site/ http://www.kyngchaos.com/software/qgis

Sketchup tips

  1. In each version, you can get the default plugins path, by opening the Ruby Console and typing: Sketchup::find_support_file(“Plugins”)
  2. To copy a component on a Mac the  “right hand options” key is the right hand alt key. So select the Move function and press right hand alt and a + appears beside the move marker, then just move and a new copy appears.   THEN … to create several copies inbetween the new and old complete the move and enter 5/ to get 5 equally spaced items.
  3. To mark a face with components that are touching it edit the component, select the face and edit->intersect with model.  There is also an option to copy from the touching part and “past in place” http://readwatchdo.com/2012/03/9th-of-10-things-i-wish-i-had-known-about-sketchup/

Creating DXF laser cut paths from Sketchup

A) Using a plugin


Import the plugin using Sketchup->Preferences->Extensions->Install Extensions.  There is a warning so import at your own peril (I imported the plugin and then manually opened the .rbz file with a text editor and checked the code for any potential dubious file activities, it looked clean).

For laser cutter, needs to have the components lying flat on the floor, i.e. view from above or below and export using “lines”.

B) The manual way (slow and buggy) :

Put Sketchup into View->Face Style->WIREFRAME

Select the component(s) and create one large component.

1) Select the component and use the plugin Edit->Component->TF Make Shop Drawings to output a shop drawing style sketchup page. Save and open the drawings file


2) Select the required component, select Camera->Standard View->Left/Top/Bottom etc to get a face on view

File->Export->2D Graphic (TIFF image)

Screen Shot 2014-10-11 at 15.56.37

In Inkscape create a new file and File->Import the TIFF file.

Select the object and Path->Trace Bitmap using (untick Smooth unless you need it):

Screen Shot 2014-10-11 at 16.11.16

Select the Fill tool and Fill in black (black fill and black stroke width 1mm)

Screen Shot 2014-10-11 at 18.20.43

Save the file as a dxf (Didn’t use default LWPOLYLINE) :Screen Shot 2014-10-11 at 16.00.09Screen Shot 2014-10-11 at 16.02.29

Ready for opening with LaserCut 5.3 (objects will need to be resized).