VS3D - Text Carving Tutorial

This tutorial shows how to use VS3D to create tool paths for carving text. Two scenarios are presented:
Scenario 1: The text to be carved is contained in an imported digital image (a scan of a logo, for example).
Scenario 2: The text graphic is created directly in VS3D.

NOTE:
This tutorial utilizes the VS3D "Region Perimeter" tool path type. Subtle improvements were made in the VS3D Region Perimeter tool path calculations. These improvements were implemented in VS3D version 1.33 . Earlier versions will still work, but the resulting tool paths may be disjointed when using VS3D version 1.31B or earlier.

SCENARIO 1 - Import and carve a scanned logo graphic.

The image used in this example is shown below. Click the RIGHT mouse button on this image to download it onto your computer.

1. Import the logo image.
Start VS3D. Select the main VS3D "File -> Import Image Brightness as Height..." menu. Enter the settings as shown below. Use only the "Red" image band on layer 1 (the "Red on 1" setting). Some images are stored "top-down" and others are stored "bottom-up" (this refers to the order in which the pixel rows are stored in the image file). In this case, enable the "Flip Vertical" setting. Set the minimum height to -1 and the maximum height to 0. The resulting surface will be at a Z height of -1 where the image is black, and a surface height of 0 where the image is white. If the image contained gray-scale values, they would be mapped to surface heights between -1 and 0 in this case.

Note that this is a fairly small low-resolution image (400x200 pixels). Higher-resolution images will yield finer detail.

2. Set up the coordinate scales.
Select the main "Edit -> Coordinate Scale..." menu. Enter the X range 0,4 and the Y range 0,2 as shown. Note that the X and Y coordinate scales are proportional to the pixel (surface grid) size of 400x200. In this case, the physical grid point spacing in VS3D is 100 grid points per inch (400/4 = 100 = 200/2).

Switch the main VS3D mode to "Display". Change the "Z Height Shade Range" values to 0.000000, 0.200000 as shown. This will emphasize the apparent relief of the surface. Click on the "Show Rulers" button.

3. Trace the logo.
Switch the main VS3D mode to "Region". Set the "Define/Modify Region" mode to "Contour". Click on the "Geometry..." button. Enter a contour level of -0.1 .

Note that this will trace the existing surface at a Z height of -0.1 (which is between the minimum surface height of -1 and the maximum height of 0). The resulting region will enclose all parts of the surface that are equal to or higher than -0.1 . To switch the region so that it covers the letters and not the background, select "Swap in/out" from the Region "Modify" drop-down menu. The region outlines will look the same, but the red Region Out/In indicator will show that the letters are now inside the region when the cursor is moved across a letter.

4. Find the letter centerlines.
Select "Skeleton" from the Region "Modify" drop-down menu. The region perimeter will now follow the "Skeleton" (centerlines) of the previous region.

For the tool path to be calculated correctly, it is sometimes necessary for the region to have some width to it. To expand the skeleton width, choose "Expand..." from the Region "Modify" drop-down menu. In the "Expand Region" pop-up dialog, leave the "Expand Width" set to "3" and click on "Ok". The perimeter of the skeleton is then expanded slightly.

5. Generate the tool path.
Switch the main VS3D mode to "Machine". Click on the Cutting Protocol "New..." button. Select the desired machine type and leave the other defaults.

The surface will now appear flat because the existing material (before cutting) is now shown.

Choose the tool bit parameters such that they mimic a 1/2" diameter 90 degree V-bit.
Tool Type: Cone
R: 0.25 (0.25 radius = 0.5" diameter)
O: 0.0
H: 0.25
D: 0.25

Choose the Cutting Path type "Region Perimeter". Set the "Maximum Path Depth" to 1.0 (the actual cutting path depth in this case will be limited by the shape of the tool bit, the shape of the letters, and the tool's "D" parameter). The other Cutting Path settings have no effect when the Path Type is "Region Perimeter".

Click on the "Make Cuts / Add to Protocol..." button. If you are running a licensed version of VS3D, you will be prompted to enter additional tool path parameters (cutting speed, etc.) and also the name of the output machine file. Click on "Ok" when the tool path is completed.

Note how VS3D automatically adjusted the tool path up and down so that the V-bit would fill the width of the letters at each point.

Note that VS3D versions 1.4 and newer include additional tools for specifying the "climb" or "descend" direction of the tool path.


SCENARIO 2 - Define the text graphic in VS3D and then carve it.

1. Set up the surface.
If VS3D is already running from Scenario 1, select the main "Edit -> Erase Surface" menu, and switch to "Region" mode and click on the Region "Reset" button. Then skip the rest of this Step 1 and go to Step 2 below.

If just starting VS3D, select the main "Edit -> Resize Grid..." menu. Enter a Grid X size of 400 points and a Grid Y size of 200 points. Set up the coordinate scales in the same manner as Step 2 from Scenario 1 above. Then continue to Step 2 below.

2. Define the logo geometry.
Switch the main VS3D mode to "Region". Set the Define/Modify Region mode to "Polygon (X=Y)". Click on the "Geometry..." button. Set the coordinate system to "Data Units" and enter the values as shown:

Switch the Region Add/Remove mode to "Remove". Click on the "Geometry..." button. Enter the values as shown:

Note how this removed a portion from the region (due to the "Remove" mode), leaving a crescent shape. Also note that if you make an error, you can Undo the last change made to the region by selecting "Undo Region ___" from the main "Edit" menu. This will be the second choice from the top of the Edit menu (the first item in the Edit menu is always an Undo/Redo function which applies to changes made to the surface heights, not changes to the region outlines).

Switch the Region Add/Remove mode back to "Add". Change the Region Define/Modify mode to "Text". Click on the "Geometry..." button. Enter the values shown in the "Define Text Region" dialog as shown. Different systems will have different True-Type fonts available, so you will likely have to choose a different font and/or Height setting. Click on the "Display" button to see a preview of the text as blue outlines drawn on the surface. Click on "Ok" when ready to define the text region.

3. Prepare the logo for machining.
Set the Apply Region "Z:" value to -1. Select "Plateau" from the "Sculpt" drop-down menu. This will set all the surface Z heights within the entire region (text and crescent) to -1. The exact depth is not critical, so long as it is deeper than the maximum depth you plan to cut.

4. Find the letter centerlines.
Select "Skeleton" from the Region "Modify" drop-down menu. The region perimeter will now follow the "Skeleton" (centerlines) of the previous region.

For the tool path to be calculated correctly, it is sometimes necessary for the region to have some width to it. To expand the skeleton width, choose "Expand..." from the Region "Modify" drop-down menu. In the "Expand Region" pop-up dialog, leave the "Expand Width" set to "3" and click on "Ok". The perimeter of the skeleton is then expanded slightly.

5. Generate the tool path.
Now just follow the instructions from Step 5 in Scenario 1 above.

 

A complete tutorial for VS3D / VScad3 is available via the main VS3D "Help" menu, or by clicking on the link below:
VS3D / VScad3 Documentation


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