V-Carving Tutorial
(V-Carve Almost Anything Using F-Engrave Image Mode)
<![if !vml]>
<![endif]> <![if !vml]>
<![endif]><![if !vml]>
<![endif]>
To successfully use this tutorial F-Engrave and Potrace need to be installed and working. Help installing these programs is availableat: F-EngraveSetup
Step 1. Select animage to v-carve.
Any image that is black and white or that you can convert toblack and white.
Step 2. Convert theimage to a format that F-Engrave can import.
Assuming Potrace is installed andworking properly the image types that can be imported are: BMP (WindowsBitmap), PBM (Portable Bitmap), PGM (Portable Graymap)and PPM (Portable Pixmap).
The input image should be converted to black and white usingany image editing software. If pixelvalues other than black and white appear in the input, they will be convertedto black and white within F-Engrave (Potrace actuallydoes the work). Color or grayscalepicture will produce a result but the internal conversion does not allow you topreview the true input. (additionally,the size of true black and white images is dramatically smaller than grayscaleand color images.)
Step 3. Import theimage into F-Engrave
3a. Open F-Engrave
- Windows:Double click the f-engrave.exe file.
- Linux:Type python f-engrave-xx.py at acommand prompt. (where xx is the version number)
3b. Change the mode to image [ Settings - Image Mode ]
<![if !vml]> <![endif]><![if !mso]> 3b.
<![endif]><![if !vml]>
<![endif]>
3c. Open your image file by selecting [ File - OpenDXF/Bitmap File ] then use the file open dialog tonavigate to and select an image file.
<![if !vml]> <![endif]><![if !mso]> 3c.
<![endif]><![if !vml]>
<![endif]>
Step 4. Change themain window settings to set the output size and cut method.
4a. Adjust the size of the image. This is accomplished by changing the Image height property. The resulting image size is displayed in thestatus bar.
4b. Change the FeedRate and Z Safe values to valuesthat are suitable for your machine and material. The defaults are pretty safe for mostoperations (when using English units) increasing the Feed Rate and decreasing the ZSafe can help improve the speed of the carving process. (for V-Carving the Cut Depth is determined by the v-bitgeometry, which will be set later, so there is no need to change this valueunless you are using engrave mode)
4c. Since we will be v-carving, select V-Carve mode at the bottom of the window.
4d. The Origin option can be modified to changethe zero position of the g-code output if desired. The current position of the origin isdisplayed on the preview window by red and blue lines (shown in the lower leftin the image below).
4e. After changingsettings on the main screen click the Recalculatebutton to update the display.
<![if !vml]> <![endif]><![if !mso]> 4e. <![endif]><![if !mso]> 4b. <![endif]><![if !mso]> 4c. <![endif]><![if !mso]> 4a. <![endif]><![if !mso]> 4d.
<![endif]><![if !vml]>
<![endif]><![if !vml]>
<![endif]><![if !vml]>
<![endif]><![if !vml]>
<![endif]><![if !vml]>
<![endif]>
Step 5. Change theV-Carve Settings
5a. Open the V-CarveSettings window [ Settings - V-Carve Settings ]
<![if !vml]> <![endif]><![if !mso]> 5a.
<![endif]><![if !vml]>
<![endif]>
5b. Set the V-Bit Angle and V-Bit Diameter to match your cutting bit. The V-Bit Diameter can be set to diametersless than the actual cutting bit diameter to limit the depth of v-carving.
<![if !vml]> <![endif]><![if !mso]> 5b. <![endif]><![if !mso]> 6a.
<![endif]><![if !vml]>
<![endif]><![if !vml]>
<![endif]>
Step 6. ExecuteV-Carve Calculation
6a. All of thenecessary settings have been changed.Executed the V-Carve calculation by clicking the Calculate V-Carve button on the v-carvesettings window.
As the calculation is performed the display will update anda status window will give an estimate of the time remaining. When the calculation is complete the blueareas will be replaced by black and the tool paths will be shown as whitelines. This process can take a long timefor complex designs.
<![if !vml]>
<![endif]>
<![if !vml]>
<![endif]>
Step 7. Review theResults
The areas that will be touched by the v-bit are shown inblack and the tool paths are shown in white.As seen in the screenshot some areas of the image have not beencarved. These regions can be cleaned upusing the cleanup section of the V-Carve Settings window.
<![if !vml]>
<![endif]>
Step 8. Clean UpSettings
8a. Enter the cleanupcut data:
Cleanup Cut Diameter:Diameter of the cleanup bit to be used. (typically, a straight flat nosed bit)
Cleanup Cut Step Over:Step over distance for the cleanup cuts.Entered as a percentage of the bit diameter
Cleanup CutDirections: The cut direction to use for the cleanup bit, "X"lines in the x-direction, "Y" lines in the y-direction, "P"cut the perimeter of the uncut area.
8b. Enter the v-bitcleanup cut data:
V-bit cleanup is cutting the tight corners that the cleanupbit cannot reach. The v-bit specified for v-carving is used for this operation.
Cleanup Cut Step Over:Step over distance for the cleanup cuts.Entered as a distance.
Cleanup CutDirections: The cut direction to use for the v-bit cleanup, "X"lines in the x-direction, "Y" lines in the y-direction, "P"cut the perimeter of the uncut area.
<![if !vml]> <![endif]><![if !mso]> 9a. <![endif]><![if !mso]> 8b. <![endif]><![if !mso]> 8a.
<![endif]><![if !vml]>
<![endif]><![if !vml]>
<![endif]><![if !vml]>
<![endif]>
Step 9. Clean UpExecution and Save
9a. The cleanup calculation can now be executed using the Calculate Cleanup button on the v-carve settings window.The first time this button is pressed after a v-carve operation thecleanup areas are calculated. The areasare saved and reused until the CalculateV-Carve button is press again. Afterthe cleanup calculations are complete the display will be updated. The cleanup cut area will be plotted asreddish/brown areas with white tool path lines and the v-bit tool path will beplotted as yellow lines.
The cleanup g-code and the v-bit cleanup g-code can now besaved using the buttons on the v-carve settings window. Each of the two cleanup operations should besaved to separate files. (Don't forgetto save the v-carving g-code file from the main window file menu)
The saved g-code files can now be run on a CNC machine. The output from F-Engrave is compatible with LinuxCNC and Mach3.
<![if !vml]>
<![endif]>
Extra Credit
To make the second carving shown at the beginning of thisdocument two settings need to be adjusted.First the normals of the image need to be flipped(in the v-carve settings window). Thischanges the side of the image that gets carved so that the white gets carveinstead of the black in the image.Second a bounding box is added to the image to limit the amount ofmaterial that is removed around the image (in the general settingswindow). A screenshot after all of thecalculations are performed for this case is shown below (next page). See if you can do similar with your image.
<![if !vml]>
<![endif]><![if !vml]>
<![endif]>
<![if !vml]>
<![endif]><![if !vml]>
<![endif]>
<![if !vml]>
<![endif]>
Additional notes
Looking closely at the images on the first page reveals thatsome detail is missing from the carving.In the left image detail is missing from the eagle’s face. The image on the right is clearly missingdetail from the eagles feet. The g-code output included these details butthe v-bit used to carve the images did not come to a true point. The diameter of the tip is 0.040 inches soany features less than 0.040 inches in the output design will be lost becausethe bit is cutting air.
Good Luck!
Scorch
F-EngraveHome
