VS3D Image Embossing/Engraving Tutorial
This tutorial shows how to use VS3D to create tool paths directly from a digital image.
To illustrate the process, the exact steps to perform within VS3D will be shown below, using an example image of a young girl. A "jpeg" (compressed) version of the image is shown below. This image can be used, but a "tiff" version will give slightly better results. Click on the image to download the tiff version to your computer. You can also use a completely different image in this tutorial if you wish. Images with broadly-diffused lighting and no harsh shadows provide the best results, usually.
1. Import the Image.
Start VS3D and select the main "File -> Import -> Image Brightness as Height..." menu.
In the file selection dialog, choose the "girl.tif" file that was downloaded by clicking on the above image.
The "Import Pixel Image as Surface Height" dialog will appear. Enter the settings as shown:
Since this is a color image, there are three brightness bands contained in it (Red, Green, and Blue). Use the Red band and insert it on VS3D Layer 1 (the "Red on 1" setting). Some image formats are stored "bottom up" and others "top down". For this example, leave the "Flip Image Vertically" setting on "No" (but you may need to specify "Yes" if using a different image). The minimum brightness/height setting should be -0.125 (minus one-eighth of an inch). The maximum brightness/height setting should be 0. This will map the darkest parts of the image to a surface height of -0.125 and the brightest parts to a height of 0. Leave all the other fields with their default values and click on "Ok".
2. Set up Coordinate System.
The Z coordinates (surface depths) have already been defined via the image import process (-0.125 to 0.0). To define the physical XY dimensions of the part, select the main "Edit -> Coordinate Scale..." menu. In the "Data Coordinate Scales" dialog, enter values as shown:
This will set an X scale range of 0 to 4 (4 inches wide), and a Y scale range of 0 to 5 (5 inches high). Click on "Ok". Since the aspect ratio of the image is not exactly 4:5, the Y scale will be adjusted automatically:
Click on "Ok".
Switch the main VS3D mode from "Hammer" to "Display". Click on the "Show Rulers" button. You can now see exactly what the size of the part will be:
3. Set up Machining Parameters.
Switch the main VS3D mode from "Display" to "Machine".
Click on the Cutting Protocol "New" button. In the "New Machining Protocol" dialog, leave all settings as is (but you may want to change the output type from "G-Code" to something else, depending upon the type of machine you have):
Click on "Ok". The surface will now look flat. That is because you are now seeing what the existing material looks like before any cuts (a flat surface at Z=0, as specified by the new machining protocol). The image surface is still in there - it will be revealed by applying appropriate tool paths.
Enter the following "Cutting Tool" parameters:
Press the keyboard "Enter" key in any of these fields to see a plot of the tool's profile.
Enter the following "Cutting Path" parameters:
Type: Traverse Horizontal
Entire Surface mode
Step-Over Spacing: 0.0625
Maximum Path Depth: 0.25
4. Output a Rough-Cut Tool Path
Click on the "Make Cuts / Add To Protocol..." button.
In the "Tool Path File Parameters" dialog, enter appropriate "Spindle RPM", "Feed Rate (XY)", and "Plunge Rate (Z)" settings for your situation. Leave all fields with their default settings (note that if you are running VS3D in "Demo" mode, this dialog will not appear, and version 1.55 or newer of VS3D has additional fields not shown here):
Click on "Ok". A file selection dialog will appear for you to select the name of the ".cnc" G-Code file (or other type) to save.
The proposed tool path is plotted over the surface as circles and lines:
Click on "Ok" when the path is finished.
Note that VS3D versions 1.4 and newer include additional tools for specifying the "climb" or "descend" direction of the tool path.
The predicted results of the cutting pass are shown in the surface display. Note the horizontal grooves left by the ball-end cutter:
5. Overlay a Second Tool Path.
Switch the main mode from "Machine" to "Region". Click on the "Select All" button. Switch back to "Machine" Mode.
Change the "Cutting Path" Type to "Traverse Vertical". Change the region mode to "Region Only". Since the entire surface is in the region (due to the "Select All" operation), the tool will not lift from the surface even when it is not cutting anything. Change the "Step-Over Spacing" to 0.03125 . Click on "Make Cuts / Add to Protocol...". The vertical tool pass will cut down most of the ridges left by the horizontal pass:
6. Generate a Finishing Pass.
Change the "Cutting Tool" Type to "Cone". Change the Cutting Tool "H" parameter to 0.2165 . Press the enter key while in the "H" field to plot the updated profile. Note that this is a 1/4" (diameter) 60-degree V-Bit.
Change the "Step-Over Spacing" to 0.025 .
Click on the "Make Cuts / Add to Protocol..." button. The final part after the cutting passes will look like this:
If you are cutting in a relatively soft material (wood, plastic, etc.), you can probably skip the roughing passes and go straight to the final V-Bit pass using a narrow step-over.
You may also save your work, in case you want to apply different tool paths later. Just select the main "File -> Save Relief..." menu. Next time you start VS3D, use the main "File -> Load Relief..." menu to restore your work.
Wayne Locke ran the part on his ShopBot router. After a light snading and painting, here is the final result:
Below are links to three sample G-Code files output by VS3D. These carve the girl image above, approximately 3/8" deep, with an overall size of 8" by 12" (coordinate origin at center). A 60-degree 0.5" diameter "V" bit should be used for all three passes. The first pass is a horizontal traversal using a "climb" cut. The second pass is a vertical traversal using an alternating cut. The third pass cuts the letters. The horizontal pass should be run before the vertical pass.
A complete tutorial for VS3D / VScad3 is available via the main VS3D "Help" menu, or by clicking on the link below:
VS3D / VScad3 Documentation