Tutorial G Code

Overview: Image to Go Code imports most digital image files into G-Code format that can be ran with most computer numerical control routers and mills. The software package includes: A basic digital image editor to allow you to retouch the image before send it to the g-code converter. The converter reads the pixels information directly from imported image and creates the g-code file. Before the g-code file is created the size of the carving dimensions and the maximum tool depth can be increased or decrease without the need to reprocess the image. Image resolution can also be adjusted using several methods like the k-factor, axis combine, reverse, close enough and the x and y axis. Prep-code and post-code can be edited with the G-Code Editor built into the application for easy access and more. Image to G-Code can convert raster images to vectors also. Image to G-Code also imports DXF files from most CAD programs. (AutoCAD release 12 compatible), the importer support most geometric entities including inserts [with nested blocks]. After the DXF file is imported all supported entities are put in list organized by layers. The G-Code setup options form allows you to set layer level priorities including turning on and off the layer, set the tool release plane, close enough, default Z-Axis character, pre-code and post-code, optimize, and more. Image to G-Code also includes a little CAD drawing editor that allows you to modify imported DXF-Files, convert True Type Fonts to vectors, and draw lines, circles, polygons, arcs and more. The built in G-Code editor is a text editor with the basic find and replaced functions, clipboard support, undo and redo, math expression parser, triangle and distance between two points calculators and G-Code M-Code panel that includes most G and M codes formatted syntax including circular interpolation calculations. Image to G-Code is a fully integrated for easy interaction and its graphic user interface is similar to most Microsoft Windows© applications found in the market today.

©Image to G Code ([email protected])

License and Registration; Image to G-Code is a shareware program; you can use Image to G-Code free for a 30 days try period. After the try period the G-Code converter functionality stops and you must register the program to continue to use the converter functions. Image to G-Code Graphics utilities are free. You do not need to register Image to G-Code to use the program graphics capabilities. To register Image to G-Code Click Here.


http://www.shareit.com/product.html?productid=163263&languageid=1&stylefrom=163263&backlink=http://www.imagetogcode.com&currencies=USD,USD,EUR,AUD,CAD,GBP

QUICK START: Step I:

Import the image into the image editor or acquired from you Twain compatible scanner or digital camera using the Open or Acquire menu commands in the image editor File Menu. See Acquiring Images.

Adjust the image brightness and contrast using the contrast, brightness or color tone tools or the respective menu command in the Image Menu. See Working with the Image Editor.


STEP II

Create the G-Code file. Click on File Menu Create G-Code. On the G-Code setup form set the carving dimensions, set maximum cut depth and the x-y resolution adjusting the spin edit controls, click on the create G-Code to open the save dialog box and write the file to the disk.

Optionally before create the G-Code file set the k-factor, the close enough, the x-y combine and the reverse options. See working with the g-code setup form.


STEP III Machine the Image G code file into a finished wood engraving, apply a light coat of wood stain and sand it with very fine paper.


Working with the G-Code Setup Form:

Image to G-Code converter uses two methods to create the g-code file. The first method was designed to emulate laser cut with a cnc router or mill, and is base on color depth. The theory of this method is to prepare the surface to apply some kind of stain that will penetrate the cut indents and create the necessary shades and shadows that will make the image to appear on the cut stock. To enhance the image light sanding is applied. What tool should I do use? Raster images store color information in a pixel unit. The pixel unit size depends on the image resolution and device capabilities. Image to G-Code defaults to 0.01 in. pixel size, the X-Y resolution is set to the pixel unit size. A tool size equal to the X-Y resolution gives the optimal results but the risk of breaking the tool is very high, plus increases the cutting time. The following examples show how to combine the image size, resolution, k-factor, and the recommended tool.


Tools we use to cut the examples shown above.

G-CODE CONVERTER PAGE 1 OPTIONS

Bitmap size: The bitmap size is given in pixel and represents the actual bitmap width and height. The Ratio is the width divide by the height. The size of the bitmap is used to calculate the resulting carving dimensions.

X-Y Resolution: Represents the area of one pixel information and is equal to the maximum tool size required to cut the image without overlapping other pixels information and is directly proportional to the machined area.

Carving dimension: The carving dimension represents the size of the bitmap to be machined projected in the material stock. Image to G-Code will try to maintain the aspect ratio of the original bitmap. The initial value is set by the program.

Combine: When YZ Axis is checked linear motion on the Y and Z axis are combined, creating a wave effect. If not checked change on the Z Axis offset 90 degrees with respect to the Y Axis motion.

Depth: Maximum depth penetration on the Z Axis. In the color table white is equal to 0 and black is equal to the depth value. If the reversed option is checked then black is equal to 0 and white is equal to depth value. K-Factor: X-axis scan line interpolation, a value of 2 will move the tool every other line, a value of 3 every two line etc… Close enough: Minimum distance before tool change


position on the Z Axis.

The math between bitmap size, X-Y resolution and carving dimension.

X-Y resolution has an initial value [default] of 0.01 in A 240 x 200 bitmap has a carving dimension of: 240 * 0.01 in. = 2.4 in. and 200 * 0.01 in = 2.0 in. Image to G-Code does not allow changing the original bitmap aspect ratio. Example A:

Increasing the carving dimension x times. Carving Dimension. X-Y Resolution. X = 2.40 in. * 3 = 7.2 in. Y = 2.00 in. * 3 = 6.0 in.

X = 7.20 / 240 = 0.03 in. Y = 6.00 / 200 = 0.03 in.

If the tool size recommended is equal to the X-Y resolution then the effect of increasing the carving dimensions allows for bigger tool diameter, in this case from 0.01 in to 0.03 in. This method was used to cut three of examples shown above using a 0.03 flat end mill. Because the cut time is proportional the bitmap size and the amount of color shades in the image; projecting the image to larger size does not have an increasing effect on the cutting time. Example B:

Using a sharp pointed vee cutter (90 degrees or 60 degrees) In general a very sharp vee tool works the best. For better details use the defaults value set by converter and uncheck the K- Factor and Close enough Boxes. To reduce the amount of overlapping (tool collision) Set the K-factor to a value of 2 and ensure that the check box is checked. This also reduces the cutting time by 2. For less detail and small output files set close enough to about 1.5 % of the maximum depth value. In other words what you really need is the tool to go deep into the dark areas and barely touch the surface in the sections with very light colors. After the image is cut apply the stain and remove the excess, let it to dry. After the stain is dry start the sanding procedure. For vee cutters keep the maximum dept of cut between 0.02 and 0.03, going deeper will cause the wider part of V to penetrate and destroy the previous cut or left no material for the next one. If you want to go deeper then reduce the image size in the image editor and then increase the carving dimension. This will increase the X-Y resolution and allows for bigger tool diameter. Remember raster bitmaps only contains color information (pixels), modifying the pixels information will also modify the appearance of the image. This is why Image to G-Code uses projective transformation.


Example C:

The Child and the Dog example. To cut this example we use the following procedure: The image was converted to gray scale, (the image was very well defined and not adjustment was required) On the G-Code Converter the X-Y resolution was set to twice the default value (0.01 * 2 = 0.020). Note that the carving dimension does not change with a change in the X-Y resolution. In this case Image to G-Code resample the original image to a factor that results in the projected image (x * X-Y resolution = Carving dimension). The depth value was se to 0.035, the K-Factor was check with a value of 2, and Close enough was unchecked. Because the tool size was increased by changing the X-Y resolution and by using a K-Factor of 2, this allows us to go deeper into the wood and create a lighted 3-D effect. Example D:

The Marilyn example: For the Marilyn example we use a procedure similar to the Example A. the only change was to use a piece of stock that was pre stained and varnished. This appears to give a cleaner cut. Also when we apply the stain to the cut area this did not penetrate the areas with the varnish applied, after sanding some of the hair areas took some type of golden color.


G-Code converter Options II:

The option II of the G-Code converter was designed for images composed mostly of solid colors, like shapes and letters, and allows the user to have more control over the tool selection and material removal. The method is also base in color depth similar to a mesh created from the image. See example bellow.


Figure 1 Bitmap object

Figure 2 Tool path


Bitmap size: The bitmap size is given in pixel and represents the actual bitmap width and height. The Ratio is the width divide by the height. The size of the bitmap is used to calculate the resulting carving dimensions.

Combine: When YZ Axis is checked linear motion on the Y and Z axis are combined, creating a wave effect. If not checked change on the Z Axis offset 90 degrees with respect to the Y Axis motion.

The tool diameter.

Mill vertical and Mill Horizontal define the direction of milling process. When both checked the g-code file contain code for a vertical pass and then for a horizontal pass

Tool geometric

Carving dimension: The carving dimension represents the size of the bitmap to be machined projected in the material stock. Image to G-Code will try to maintain the aspect ratio of the original bitmap. The initial value is set by the program.

Depth: Maximum depth penetration on the Z Axis. In the color table white is equal to 0 and black is equal to the depth value. If the reversed option is checked then black is equal to 0 and white is equal to depth value. Adv. Steps: The steps required to advance the tool its full diameter base in the tool geometric. Side Steps: The steps required to advance the tool its full diameter each scan line base in the tool geometric.


Creating a new project:

Click New Photo project.

Enter the width and height of the carving dimension and select the unit type.


In the project editor click on the open image button and select the image file.

The default image position is one unit from top and one unit from left.



Selecting, moving, resizing, and rotating objects:

To select an object: Click anywhere inside the object, if the object is selected it gets focused showing the editing handles according to the object type and the document edit mode. To move the object, click and drag the object holding the mouse button down. To resize the object: move the mouse to one of the object handles until it gets selected, click and drag holding the mouse button down.

To select more than one object: hold down the ctrl key and click the objects you want to select. When selecting more than one object the last object selected gets focused. Move: apply to the selected objects; resizing and rotating only apply to the focused object. To apply an action on multiple objects click the group objects button. To ungroup the object select the objects group and click the ungroup button.

To rotate the object: Click the rotate button to set rotate editing mode. When rotate editing is set selected the objects editing handles on the four corners of the bounding box change to round dots, move the mouse over the rotating handle, press and hold the left mouse button while moving in the direction you want to rotate.

To send the object back: select the object and click the send to back button. To bring the object to the front: select the object and click bring to front button. To add caption double click to invoke the input text box.

Add text object:

After the bounding box for the text is created double click any where inside the box to invoke the text editor

Type your text in the edit box and click Ok button. After the text is added you can change the font and font color, move, rotate, and resize the object as you like.


Preparing the image for create the g-code file:


Reset Scaling to 100 %. Click create final image button. Click the finish button to bring the g-code converter setup form. Optionally send the image to Image Editor for additional processing, or save it to file.


Raster to vectors: The image editor includes several methods for converting raster images to vectors. To access the raster to vector options select any of the RTV…. commands in the file menu.


RTV Outlines:

• Convert the image to black and white. • Select RTV Outlines from the file menu. • Select the vector output (Poly-line or Bezier-line) • Click the scan button (Scan the image palette and create matrixes). If the scan

procedure succeed the program enable the execute method (Run Button is visible). • Click the run button (A new vector layer is created and added to the layer list) • Click the finish button finish.


Once the new vector layer is created you need to set the Z-Values for the new vectors.

Click on the Cad Editor Button to send the image to CAD Editor.


The CAD Editor allows you to edit and modify the new vectors entities and set the Z-Values. In this example we going to remove the image border and set the Z-Value as specific.

Actions in the CAD Editor are controlled by the program task manager. To start a new task you must select one from the draw panel. For example to draw a new line you click on the Line Button. The new line task initializes and expects you to select the line start point followed by the line second point. Deleting entities: Click the delete button to start the delete task. Select entities to be deleted (move the mouse and click on any entity segment). The delete task must be explicitly confirmed To confirm a task: Right click on the editor view port and from the pop menu select accept or cancel menu command.


1. Delete button (delete task initializes). 2. Mouse pointer changed to select entities. 3. Target entity to be selected. 4. Pop menu to confirm the task action.


Changing the Z-Value:

Enter a value on the Z-Value spin edit control For example -0.003 inches. Right mouse click the view port and select [Use area to select objects] menu command.

Click on Z-Value Button to start the z-value task. Draw a rectangle big enough to enclose the entities. To abort the operation you must cancel from the view port pop menu before the second point of the selection rectangle is defined.


Creating the G-Code File:

1. Click Create G-Code button command. 2. In the save dialog box select folder a type the file name 3. Click the save button.


• In the Convert Entities to G-Code dialog box: • Click the optimize button. • After the optimize procedure the Make G-Code button shows. • Click the make G-Code command button. • After The G-Code file is created the Preview button shows. • Click the Preview command button to preview the tool path.


Tutorial G Code

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