Prototyping Log

CamBam

21 mm birch plywood.

Based on this: http://www.cambam.info/doc/plus/tutorials/3DProfile.htm

Open STL in CamBam.

Object moved, so the topmost point is placed at z=0.

Under “Machining” set Fast Plunge Height to “0.2″.

Waterline roughing pass (3mm chipbreaker)

Profile 3D Method: Waterline Rough

Boundary Margin: 1.5

Boundary Method: Shape Outline

Boundary Taper: 1.5

Clearance Plane: 1

Depth Increment: 1.5

Cut Feedrate: 6000

Plunge Feedrate: 3000

Lead In Move: Spiral, Spiral Angle: 5

Cut Ordering: Level First

Roughing/Finishing: Roughing

Spindle Speed: 15000

Roughing Clearance: 1

StepOver: 0.5

Tool Diameter: 3

Tool Profile: End Mill

Waterline finishing Pass (3mm downcut two-flute endmill)

Profile 3D Method: Waterline Finish

Boundary Margin: 1.5

Boundary Method: Shape Outline

Boundary Taper: 1.5

Clearance Plane: 1

Depth Increment: 0.5

Cut Feedrate: 6000

Plunge Feedrate: 3000

Roughing/Finishing: Finishing

Spindle Speed: 15000

Resolution: 0.1

StepOver: 0.2

Tool Diameter: 3

Tool Profile: End Mill

Here I take a 6.6 x 6.6 km piece of the real world and turn it into a 22 x 22 cm model. This translates to a 1:30.000 scale.

ArcMap

Load the DEM into the Table of Contents.

Draw a rectangle defining the area of interest. Choose some nice round dimensions in whole metres - it makes things easier.

Select the rectangle.

Right click the DEM > Export Data.

Choose “Selected Graphics” in “Extent” and “Use Renderer” under “Output Raster”. I set the “Cell size” to “4″ to get a reasonable file size for a 6.6 x 6.6km square.

Select “TIFF” as “Format”.

Save. Do not add to map.

Repeat the export process, but uncheck “Use Renderer”.

Save. Add to map.

Not the difference between High and Low values, this is needed in AccuTrans.

The reason for exporting two different files is because Accutrans can only read the rendered TIFF-file, but to get the correct height values the unrendered version is needed with ArcMap.

AccuTrans

Open the exported TIFF file by going to File > Open DEM > Bitmap to DEM.

Set “Multiplier 2″ to 1, and “X and Y Spacing” to 1 as well. OK.

Click the “->3D” button. The vertex interval should autoselect to something reasonable. In this case “4″ resulting in 339,488 triangles. OK.

Go to Tools_1 > Adjust Object. Click “Calculate Scale”. Select X axis and enter “220″ into “New Size”. Calculate. OK.

Click “Scale”. The dimensions will update, but the image displayed will remain the same. 

Click “Calculate Scale”. Now take the delta-height measurement (divided by ten) from ArcMap and enter it into the Z-axis box (in this case 6,1 - corresponding to 61m). Calculate. OK.

Enter “1″ into the boxes for “X” and “Y” and leave the “Z”-measurement as it just was calculated. Click “Scale”.

The model now is 1:1:1. Click “Set Min at 0,0,0″ to get things straight.

Click the “Extrude” button.

Enter the material thickness minus the z-height of the surface to be milled. This should be a positive number! Click “Extrude”. Select “Flat Bottom”. OK.

The z-height should now be shown as the thickness of the stock material.

Go to File > Save As > StereoLithography (Binary).

CamBam

Birch plywood.

3mm roughing cutter.

Based on this: http://www.cambam.info/doc/plus/tutorials/3DProfile.htm

Open file in CamBam.

Object moved, so the topmost point is placed at z=0.

Roughing Pass

Profile 3D Method: Waterline Rough

Boundary Margin: 2

Boundary Taper: 1.5

Clearance Plane: 3

Depth Increment: 1.5

Cut Feedrate: 3000

Lead In Move: Spiral, Spiral Angle: 3

Cut Ordering: Level First

Spindle Speed: 15000

Roughing Clearance: 1

StepOver: 0.5

Tool Diameter: 3

Tool Profile: End Mill

Scanline Finishing Pass

Profile 3D Method: Horizontal

Boundary Margin: 2

Boundary Taper: 1.5

Depth Increment: 0

Cut Feedrate: 3000

Roughing/Finishing: Finishing

Spindle Speed: 15000

Resolution: 0.1

StepOver: 0.2

Tool Diameter: 3

Tool Profile: End Mill

I decided to cut the model into four pieces and cut one of the 11x11cm pieces.

Having printed the same object sliced with Makerbot Desktop and Skeinforge and using hairspray or glue stick on masking tape, one of the combinations was clearly winning.

Hairspray + modified Skeinforge raft. 

The hairspray kept the first layer better adhered to the tape, and the Skeinforge raft code just worked better, partly because the Makerbot code printed too fast, and that my homemade code created a significantly larger raft at a slower speed.

I might want to use part of the Makerbot starting code that draws a line along the perimeter of the build plate to clear any old filament. The Skeinforge approach is to extrude a blob for two seconds, which almost always gets stuck in the print. So I have removed that line - it is "G4 P2000".

After running the point file information tool in ArcMap I could see that many of my LAS-datasets had an average point spacing of about 0,25 points per metre compared to the 0,40 that the publicly available GeoTiffs are provided with, so I regenerated a raster to see the difference. I'm not sure if it will make a huge difference when I print this house out in 1:500 with 0,1mm layer height, but if the information is there - why not use it?

0,1mm layer height in scale 1:500 corresponds to 5cm in real life, which is the vertical uncertainty of the model, so it probably doesn't make any sense to go any further anyway.

3D-prints of the Danish terrain model.

Gentofte Kommune, terrain model, 1:40.000

One of the reasons for changing to Cura for slicing is that the Brim feature is integrated. Luckily some clever people have made a mod for Skeinforge that allows this as well. I found a file called skirt_with_brim.py somewhere online, searched for the file skirt.py on my computer, renamed the old version skirt_backup.py and the new file to skirt.py.

Within the skeinforge settings in the slicing profiles there is now a possibility to set a brim width. 

"Activate skirt" needs to be checked, "Convex" can be unckecked, if you want the brim to follow the shape of the print. "Gap over perimeter width" I set to 0, since I wanted the brim to hug the base and meld together with it. "Layers To" is the height of the brim in layers. The "Brim Width" defines the width in lines, so this will change according to the filament size etc. Remember to disable rafts, or things will look strange.

Opening up the resulting file in Repetier Host clearly shows the brim - and a problem I read on the internet, that objects are completely off center. An stl/g-code centered in Replicator G will have its centrepoint on one of the cornes in Repetier Host.

I checked what happens with the width of the brim when using my standard settings for a Replicator2 by exporting g-code with and without a brim and checking the dimensions at http://gcode.ws/ - a handy website for previewing g-code.

15 layers of brim gave me 6,6mm extra width, which makes 0,22mm per layer added, since there are 15 layers on both sides of the model.

After fiddling around with Repetier Host and Cura for slicing, it occured to me that I had no idea if the settings in the configuration would work or not. So even though the slicing time was impressive, I went back to skeinforge on ReplicatorG, because I don't have a machine to do extensive testing on.

So to fix the slow slicing speed, I changed to a different Python interpreter, in this case PyPy. Since ReplicatorG uses Python 2.7, you need to make sure to get the right version from here.

Unpack the file somewhere handy, go to ReplicatorG settings and navigate to the PyPy.exe in the Python interpreter settings. Slicing should be 5-10 times faster now. Not sure how muchn I gained, but what used to take at least 45 minutes now takes about 5, so I'm happy!

To make a 3D mesh model from raster data in ArcMap.

Draw a rectangle defining the area of interest. Keep the dimensions to nice whole numbers like 26x38m.

Select the rectangle.

Right click the raster layer > Data > Export Data.

Set Extent to "Selected Graphics".

Check "Use Renderer" and "Square".

Choose a location, name and set Format to "TIFF". Click "Save".

Open Accutrans.

Go to: File > Open DEM As > Bitmap to DEM > Select the TIFF-file.

Set "Multiplier 2" to "0,5", "Minimum Height" to "0" and "X and Y Spacing" to 1.

Click the 3D-button in the toolbar at the left side of the window.

Take a look at the Min and Max Heights to see if it looks right. With the 0,5 Multiplier from the last step, it appears to be spot on every time.

Set the "Vertex Interval" to something that keeps the Triangle count below 1.000.000 for 3D-printing. Or preferably less, but it of course depends on the purpose of the model. Click "OK".

Rotate the model by depressing the "C Rotate" button at the bottom of the window to see if things look alright.

Now go to "Tools_1 >  Adjust Object" which should have appeared in the menu bar. 

Type "0,4" into the X, Y, Z boxes. The 0,4 is the distance between the points in the elevation model in ArcMap. Click "Calcualte Scale" to change the model size to anything else. Click "OK".

Click the "Extrude" button in the left-hand toolbar.

Set "Thickness" to -0,5 to give the model a 5mm base.

Select "Flat Bottom". Click "Extrude" and then "OK".

The model can now be saved as "STL" directly for 3D-printing, Collada, 3DS or anything else for further use and post-processing in MeshLab, SketchUp or whatever.

This was a tough one... but somehow I managed to work it out! The address-layer I have is point based. The Excel file has the addresses and a description in two columns.

Guide

Import the excel file by adding it to the Table of Contents.

Right click the address layer > Joins and Relates > Join.

Choose "Join attributes from a table".

Choose the address column in the address database.

Choose the Excel file as "table to join".

Choose the address-field from the Excel file.

Join options: "Keep only matching records".

OK!

Now the points which match those in the Excel file will be the only ones shown, but we need to get the descriptions as well.

Right click the address layer > Joins and Relates > Relate.

Choose the description field in the address file - or add a new empty field to receive the description from the Excel file.

Choose the Excel-file and the right worksheet inside it.

Choose the description column from the Excel file.

Name it whatever you want.

Bingo - you can now show the data with labels by changing the settings by right clicking the layer > Properties > Symbology.

Before converting LiDAR data to raster, you need to know the sample density. I found a guide that explains that quite well: Assesing LiDAR coverage and sample density. For my Danish data, the values for my approx. 70 1x1km blocks were anywhere from 0.25 to 0.65 points, so I chose to use 0.40, which is what the official rasters are presented in.

In this case I wanted to generate a raster showing only points classified as ground or building.

Extract the LAZ-files needed with LASzip and put in a folder.

Use "Create LAS Dataset" in ArcMap to get the files to show as one in ArcMap.

Activate the "LAS Dataset" toolbar and fool around a bit to see what happens.

If the "Data Percentage" in the "Table of Contents" is zero, you have to zoom in further to see anything.

Open "LAS Dataset to Raster", input the LAS dataset. Set "Value Field" to "Elevation".

Choose "Triangulation" and set "Natural Neighbor", "Point Thinning Type" to "NO_THINNING".

"Output Data Type" should be "FLOAT", "Sampling Type" to "CELLSIZE", "Sampling Value" to "0,4" (for Danish data with 0,4m spacing) and leave the "Z Factor" alone...

Click "OK" and wait patiently... for an hour or two.

The new DTM for Denmark is downloaded in 10x10km blocks, which each contain 100 1x1km blocks of information. 

For the area I was interested in, I needed to work with two adjacent data blocks, and since I didn't have the "Advanced" ArcMap licence to be able to make a Mosaic dataset out of the raster blocks, I had to find another way of working with the data.

For Sjælland and Fyn anyway. It can be found here.

The resolution of the new data is amazing: Every 1x1km block of data contains about 1 million data points, the vertical resolution is 5cm and the horizontal resolution 15cm. Each points is classified as vegetation, building, water etc. which makes it easy to get the data you want.

It can be downloaded both as a point cloud in LAZ-format (compressed LAS) and as GeoTIFFs showing Surface or Terrain.

I have taken a look at the data to see what I could make of it. 

LAZ-files

ArcMap doesn't understand LAZ-files at the moment, so I had to use the free tool LASzip to decompress them, This inflates them to 10x the size, but at least they can be used.

Fugroviewer

Alternatively they can be viewed in many programmes in their original format. For example Fugroviwer which lets you view the data in different ways, e.g. as a section or as a TIN (Triangulated Irregular Network).

Having generated a fabulous 3D mesh in SketchUp from dtm points it would be nice to get some contour lines in place to make it easier to understand. 

This can be avoided if you have built your landscape from height lines already, but this will make a much less accurate mesh due to the interpolation used to generate the lines. And the filesize is up to 40% bigger. 

Create a new layer for the contour lines and make this the active layer.

Draw a rectangle bigger than the mesh along the x-y plane. 

Group the plane.

Move the plane below the lowest point of the mesh. 

Toggling the copying function of the "Move" tool by pressing the CTRL button when moving the first layer. Make sure it's stuck to the z-axis by pressing the up-arrow button. Type the distance you want between the contour lines e.g. "50cm". Pres Enter and write the amount of times you want it copied. E.g. "x50" for a model with a maximum height difference of 25m. 

Delete any extra copies that aren't intersecting with the surface.

Hide the surface layer.

Select all the planes and group them.

Turn the surface layer back on.

Select all, right click > Intersect > Intersect with selection.

Wait patiently. This could take anywhere from a few minutes to hours depending on the model size and your CPU. SketchUp will look as though it has crashed... but it hasn't, it's just pretending.

When the operation is complete, select the group of planes and delete it. The contour lines will now be visible.

Get the digital terrain model point cloud into the "Table of Contents" in ArcMap.

If you don't have the data as a point cloud, a raster image can be converted using "Raster to Polygon".

Draw a polygon defining the area of interest. Right click on "Layers" in "Table of Contents" select "Convert Graphics to Features".

Save as shapefile somwhere convenient. Click "Yes" to add the exported data to the map.

Go to Geoprocessing > Clip. "Input Features" is the dtm. "Clip Features" is the the newly drawn polygon. "Output Feature Class" is the resulting file from the clip operation. Save it somewhere you want.

Now the points need to be turned into 3D-objects. Locate the "Feature To 3d By Attribute" tool. Input the newly generated clipped dtm in "Input Features". "Output Feature Class" is the name of the file to be generated. The "Height Field" drop-down menu shows the column headers of the data file. To make sure you get the right one, right click on the layer in the "Table of Contents" > "Open Attribute Table". Here you can see which header contains the height data. You need 3D Analyst to perform this operation.

Now the data is ready to be exported. Right click on the new layer > Data > Export to CAD. Choose whatever "Output Type" and "Output File" you want.

Before opening SketchUp, make sure you have downloaded and copied the files delaunay2.rb and points_cloud_triangulation.rb to Users/<username>/AppData/Roaming/SketchUp/SketchUp2015/SketchUp/Plugins. The files can be found somewhere on the internet.

In SketchUp go to File > Import. Choose "AutoCAD Files" in "Filetype" and find the file generated from ArcMap. Click the "Options" button at set "Units" to "Meters".

The points should be visible now. If they were exported as a DWG, they will be grouped. DXF does not do this. Open the group and select all points. Go to Extensions > Triangulate Points. Click "Yes" to pu triangles on specified layer and give the layer any name you want.

Depending on the speed of your CPU this operation could take a bit of time. A 200x200m area with 1,6m (which makes for 15625 points) between each point takes about 6 minutes on a basic office laptop. 

You can now hide the layer containing the points, right click on the new surface > Soften/Smooth Edges. Set the "Angle between normals" to 180 and check both boxes about "Smooth normals" and "Soften coplanar".

The surface has now been created. Enjoy.

Just to be able to remember my current workflow...

ArcMap: Export dtm points.

SketchUp: Import points, triangulate to surface with plugin and draw buildings.

SketchUp: Export to .stl with stl-export plugin or Collada .dae.

AccuTrans: Import, scale to size in mm. Extrude flat base -5mm.

Accutrans: Export .stl.

Netfabb: Repair model (or online at Modelrepair).

Netfabb: Import and cut oversize files into pieces. 

Repetier-Host: Open .stl file and slice with CuraEngine.

Repetier-Host: Save G-code.

ReplicatorG: Open G-code and build to .x3g for Makerbot.

Makerbot: Print file.

Coffee: Make.