HOWTO: text engraving using 3Drag/K8200 Ver. 1.0 1 The Problem 2 Hardware 3 Sofware 3.1 TextGraver 3.2 DeskEngrave 3.3 StickFont 3.4 Inkscape 4 Engraving PLA 5 Toolchain 6 Notes and References 1 The problem To create a 3D printed keyring for the awards of our Bridge club (http://www.thingiverse.com/thing:1235307 ), I wanted to engrave the text "GIOBRIDGE 2015" on the back of the PLA keyring, using 3Drag as CNC. But after breaking two bits without an acceptable result I decided to stop for a moment and review the whole thing. In this document the results of my research and testing on engraving text, it includes also a toolchain using regexfiler, a my filtering program for text files, that automates some operations on G-code, with the hope that my work will be useful to some 3Drag user. 1.2 Features required. ✔ Load the Gcode on Repetier host. ✔ Fix the object to be engraved on the bed, very horizontal. ✔ Place by hand with Repetier the end mill in correspondence of a reference point on the object. ✔ Adjust the height Z based on the depth desired. ✔ Start the drill engine, and then the G-code in Repetier. ✔ At the end the mill head is repositioned in HOME. ✔ Stop the mill and remove the object engraved In other words, I do not want an absolute code, making it compulsory to place objects in the same position on the bed, but a relative code. For the Z axis, I impose in Gcode always 2mm as low value and 5mm as high value. The start position of the mill bit is taken as 3mm (by the initial code G92 X0 Y0 Z3). Therefore, if the work begin exactly 0.7 mm above the surface, the milling depth will be 0.3 mm. I want to do that in Windows 10, using free sw, and in the simplest way possible: after all I am just a beginner in CNC. Note: I tested the software using Windows 10, but Inkscape, Notepad ++, CAMotics and
4 Engraving PLA 5 Toolchain 6 Notes and References
1 The problem
To create a 3D printed keyring for the awards of our Bridge club (http://www.thingiverse.com/thing:1235307), I wanted to engrave the text "GIOBRIDGE 2015" on the back of the PLA keyring, using 3Drag as CNC.But after breaking two bits without an acceptable result I decided to stop for a moment and review the whole thing.In this document the results of my research and testing on engraving text, it includes also a toolchain using regexfiler, a my filtering program for text files, that automates some operations on G-code, with the hope that my work will be useful to some 3Drag user.
1.2 Features required.
✔ Load the Gcode on Repetier host.✔ Fix the object to be engraved on the bed, very horizontal.✔ Place by hand with Repetier the end mill in correspondence of a reference point on
the object.✔ Adjust the height Z based on the depth desired.✔ Start the drill engine, and then the G-code in Repetier.✔ At the end the mill head is repositioned in HOME.✔ Stop the mill and remove the object engraved
In other words, I do not want an absolute code, making it compulsory to place objects in the same position on the bed, but a relative code.
For the Z axis, I impose in Gcode always 2mm as low value and 5mm as high value. The start position of the mill bit is taken as 3mm (by the initial code G92 X0 Y0 Z3). Therefore, if the work begin exactly 0.7 mm above the surface, the milling depth will be 0.3 mm.
I want to do that in Windows 10, using free sw, and in the simplest way possible: after all I am just a beginner in CNC.
Note: I tested the software using Windows 10, but Inkscape, Notepad ++, CAMotics and
Repetier have versions for different OS and the final toolchain is easily adaptable.
2 Hardware
2.1 Mill and 3Drag mount
I am using a mini-drill Valex (Brico) and a fast-clamp mount (see http://www.thingiverse.com/thing:951383 ) but you can also use a Dremel (http://www.thingiverse.com/thing:225465 ), a Parkside (Lidl) (http://www.thingiverse.com/thing:768599 ) or any rotating engine having a 3mm spindle and sufficient speed.
Note: If the cable (220/110 V) is too close to the 3Drag control board I noticed malfunctions.
2.2 3Drag quirksI do not want to alter the Marlin firmware, so the 3Drag as CNC suffers the following
limitations:◦ The 3Drag goes in error state if the extruder thermistor is not connected.
Solution: put a connector (eg. DB9) on the 8 wire extruder cable. After removing the extruder insert a plug with only a resistor of 100 KΩ that simulates the thermistor at room temperature.
Alternative: you can fix the resistor to a two pin connector that plugs directly on the controller board instead of the connection to the extruder thermistor (cable yellow/blue).
◦ The output E is disabled if the thermistor does not reports at least 170 ° CSolution: Okay so (I do not use the exit E) but just need to reduce the value of the 100 KΩ resistor in order to simulate a temperature greater than 170 ° C.
◦ X, Y, Z must have only positive valuesNote: unfortunately this is true even if you switch to Relative Positioning (G91), which makes this mode completely unusable (Marlin bug).
Solution: use appropriate starting and trailing G-code, use offsets for coordinates always positive.
2.3 Repetier: preparationIn Repetier/Printer Settings you must create a new profile, for example "3Drag-CNC", cloning the profile 3DRAG. (Repetier must be disconnected from 3Drag to do this).In "3Drag-CNC", you must delete all scripts: initial code, final code, etc.
2.4 G-code: simulation on screenI found very useful to use a simulator for a first impression about the result, or to evaluate some measures, or to see the effect of changes in Gcode, After some tests my choice is CAMotics (http://camotics.org/download.html), previously also called openSCAM.
2.5 Simulation on paper using 3Drag
After the unfortunate initial attempts I found useful, before milling, to do some tests on paper, and verify the results.
It is necessary to fix a pen on 3Drag, better using a support for pen/pencil easy to assemble. This is mine: http://www.thingiverse.com/thing:1196997.
• Uses the TTF fonts installed in Windows (see Note 2).
• Allows the definition of start and end G-code.
3.1.2 AGAINST
• Allows only straight writing.
• Allows you to save in three formats (.gc, .nc, .tap) but the content is identical. I use .nc
• Accepts only integer multiples for the size, then the minimum size can be obtained only placing the minimum height of the font (in points) in the Font Menu. (In figures: font Microsft Sans Serif. 8 points → text 6mm x 68mm)
• The origin (0,0) is in the top left, and corresponds to the corner of the rectangle that contains the first character plus more space between characters (negative Y coordinates).
• Does not save the setup: it must be re-entered at each run.
• Countries using Arabic numerals with decimal comma: I recommend the use of the decimal period with this program (see Note 1)
3.1.3 USO: Very simple and easy. Only caveat: adjust the Y Offset in setup.
1. run the "View / Generate code" with Offset X = 0, Offset Y = 0
2. put Offset Y = Y max (negative)Note: use PC-local decimal separator
Parameters – Rapid Height = 5mmLine Number – Start at = 1Line Number – Increment = 0Note: so all line numbers are N1
• Save (File – Save As G-Code) using the extension .gcode
• With an ASCII editor (e.g. Notepad ++):If required (note 1) replace all the commas (,) with a period (.) Replace all "Z-2" with "Z2"Replace all "N1 G" with "G"Replace all "N1 X" with "G00 X"Replace all "N1 F" with "G00 F"Enter START and END code, see note 3.
• Save and load in Repetier.
• Using Repetier commands, place the pen (bit) at the point of departure.
• Lower the pen (bit) until it touches (use a paper: it must be removed without breaking).
• Lift the pen exactly 1mm, (bit: 1mm less the cutting depth)
Approach Z = 3Deep Z = 2Pludge Feedrate = 200Feedrate = 100
• Initial Code (Note 3): G90 G92 X0 Y0 Z3
• End code (Note 3): G00 Z30G28 XG28 Y Z
• Save as .nc
3.3.4 USE WITH SIMULATOR (CAMotics)
• With an ASCII editor (e.g. Notepad ++) or in CAMotics, choosing "Edit File" in the context menu of Files:
• If the local do not use the decimal period (note 1) replace all the commas (,) with a period (.)
• Delete the last lines. (G0 Z30 G28 G28 X Y Z) .
• If you have used an editor, save as .ngc and load in the simulator
3.3.5 USE WITH 3Drag
• With an ASCII editor (e.g. Notepad ++):If required (note 1) replace all the commas (,) with a period (.) Replace all "X" with "G00 X" But not in the 2nd line: "G92
X0 Y0 Z3"Replace all "Y" with "Y" (space + 'Y')Replace all "Z" with "Z" (space + 'Z')Replace all "F" with "F" (space + 'F')
• Save and load in Repetier.
• Using Repetier commands, place the pen (bit) at the point of departure.
• Lower the pen (bit) until it touches (use a paper: it must be removed without breaking).
• Lift the pen exactly 1mm, (bit: 1mm less the cutting depth)
• then do the button "Start work".
….....3.4 Inkscape 0.91https://inkscape.org/en/
This program is different from the previous ones, because it is a generic vector graphics program, then more powerful but undoubtedly more complex. For example, these are the instructions to get circular texts (http://tavmjong.free.fr/INKSCAPE/MANUAL/html/Text-Path.html):
Text on a path is initially placed on the “left” side of the path (referenced from the path direction) starting at the beginning of the path. One can change the direction of the text (and the side it is placed on) by reversing the direction of the path (e.g., Path → Reverse (Shift+R)). If the text is
center justified prior to being put on a path, it will centered along the path.
To place text on a circle so that it reads from left to right on both the top and bottom, two circles must be used as seen on the left. The larger circle has been flipped horizontally (Object → Flip Horizontal (H)) so the text is placed inside the circle starting from the
left. The smaller circle has been rotated 180 degrees. (The path of a circle when first drawn starts from the rightmost point. The circle must be rotated or flipped to move the
starting point of the path to the left.) By turning the circles into half circles and setting the text to center-justified, the text will automatically be centered at the top or bottom of the
circle. Note that kerning may be necessary as the characters of text placed on the outside of a curve will be too far apart while those on the inside of a curve will be too
close together.
3.4.1 PRO
• Powerful free program for vector graphics.
• Uses the TTF fonts installed in Windows
• Allows the use of “single line open” TTF fonts: but the glyphs have to be opened by hand or with the extension reopenSingleLineFont (see Note 2).
• For linear or inclined text you can use Extensions / rendering / Text Hershey (included), which uses a private set of 'single line' fonts (not TTF), but generates graphical objects, not text.
• For text following paths you must instead use TTF font.
• You can make custom fonts (limited and requires .FontForge)
• Sizing the spacing between characters (kerning).
• Extension / Generate from path / Paths to OpenSCAD (to install) for export to OpenSCAD (http://www.thingiverse.com/thing:1065500): tested, very good.
3.4.2 AGAINST
• The use is complex, it takes longer time.
• Almost essential (wiki-Manual-see note 8) the use of the decimal period (see Note 1)
• Char sizing in Pt (but text can be resized after in mm).
3.4.3 Inkscape and G-code
I found three Inkscape extensions to create G-code:1. Gcodetools (included with Inkscape). The latest version (1.7) can be downloaded here:
http://www.cnc-club.ru/forum/viewtopic.php?f=15&p=101) . Very comprehensive but not well documented on the site, I found it difficult use, although it has nice features, such as the parametric G-code (accepted by the simulator but not by Repetier), bas-relief, etc ...
Note: I gave (with Inksape 0.91) the error "AttributeError: 'module' object has no attribute 'unittouu'". The solution shown in this post worked for me: http://www.tylerforsythe.com/2015/02/inkscape-laser-engraver-bug
2. Generate G-Code for Repetier, download (http://www.repetier.com/repetier-g-code-plugin-for-inskscape/ ) and install. It seems to be a simplified version of the previous. Very simple to use, the generated code is optimized for laser cutter and not for cnc, but this is not a problem.
3. Save As / EMC GCode: This will create a single file containing all the layers toolpaths and Extension / Export / Export as GCode: this will output one file per layer in a specified directory. This can be downloaded here: http://wiki.linuxcnc.org/cgi-bin/wiki.pl?InkscapeHowto .
Note:With the version 0.91 of Inkscape it gives me some errors.
1. Install the chosen font (in the example: the “stick font” 1CamBam_stick_3.ttf) in Windows (just copy it in the dir. C: \ Windows \ fonts)
2. Select File / Document Properties, then on the Document Properties / Page / genaral choose default units: mm. (Ditto in Grids / unit)
3. Do the text, choosing (Text / Text and character) the stick font just installed. Go to Object / Fill and stroke, then select fill: no paint, stoke paint: flat color.
4. Complete the editing, possibly with Path (in the example, circular), here online help.5. Kerning: Select the Text Tool (A), select the letters of interest in the text, and use the buttons
in the toolbar.6. Place the object in the lower left corner of the sheet (origin 0.0).7. Select all, then Object / ungroup8. In view mode / display mode / outline, and select Object / Unhide all9. Clean: select and delete one by one all the items that are unnecessary.10. Select the entire written remaining, then do Object / group11. Save (The design is finished and clean).
Estension: “Generate G-Code for Repetier”:I use this extension because it is simpler than Gcodetools.
12. Select all, then Object / ungroup13. Turn text on path: Menu Path / From Object to Path14. Execute Extensions / Generate G-Code for Repetier /
Repetir Laser Tool15. Set:
Travel Speed = 100Laser Speed = 10Folder = enter the output directoryFilename = xxxxx.nc
16. Now theApply Button
3.4.5 USE WITH SIMULATOR (CAMotics)
• With an ASCII editor (e.g. Notepad ++):Delete all lines starting with ‘M’ (M3, M5, M18, M452)Replace all "F100" with "Z5 F100"
Replace all "F10." with "Z2 F10." note: using Notepad++ set Search mode/Normal
After the row “G21” insert START code (Note 3):
G92 X0 Y0 Z3Delete last rows:
G91G90G00 X0 Y0
Insert END code, (Note 3):G00 Z30G28 XG28 Y Z
• Save the file as .ngc and load it in the simulator.
3.4.6 USE WITH 3Drag
• With an ASCII editor (e.g. Notepad ++):Delete all lines starting with ‘M’ (M3, M5, M18, M452)Replace all "F" with " F" (space+F)Replace all “F100” con “Z5 F100” Replace all “F10.” con “Z2 F10.” note: using Notepad++ set Search mode/Normal
After the row “G21” insert START code (Note 3):G92 X0 Y0 Z3
Delete last rows:G91G90G00 X0 Y0
Insert END code, (Note 3):G00 Z30G28 XG28 Y Z
• Save the file as .gcode and load it in Repetier.
• Using Repetier commands, place the pen (bit) at the point of departure.
• Lower the pen (bit) until it touches (use a paper: it must be removed without breaking).
• Lift the pen exactly 1mm, (bit: 1mm less the cutting depth)
• Pin on a sheet the coordinates X, Y, Z used, then the button "Start work
4 Engraving PLA• I used a bit for PCB, 15°, 0.1 mm, with low speeds (F10, drill with speed control halfway)
and 0.1mm deep step, with 2 or 3 passes (using 2 END)
• Acceptable results. The PLA does not melt
• Good operation of the XY axes; curves well designed, repeatability of positioning XY adequate: no problem with the second or third time.
4.1 Problems encountered:
• Excessive eccentricity of the spindle of my drill, for which the incision is larger than expected, and a milling bit is broken. On the other hand it was really small letters, only 3.6 mm high. (Solution: change spindle or change drill)
• Bug in sw Repetier (but not in Marlin): the sequence G90 G21 G92 X0 Y0 Z3 G0 Z5 F200 correctly position the tip to Z = 5, while Repetier indicates Z = 8. (Solution: ignore the indications of Z in Repetier)
• Always write the coordinates of the starting point !!! If you have to start again they are essential !!! (Solution: be precise and tidy!).
• It would be useful to carry out, before a new engraving, the tests indicated in http://www.precisebits.com/tutorials/calibrating_feeds_n_speeds.htm to find the right balance between speed / feed rate as a function of the bit and material. (Solution: provide, for the next work, a sample of the material where performing the tests)
5 Toolchain
Now I want to automate the process described above, to have it running faster and error free. We need another program and a minimum of setup.I limit this to the programs that I found most interesting: StickFont and Inkscape, for use with Repetier, and CAMotics, supposing this programs already installed and operating.
To make the changes in G-code, I use a my old java program, regexfilter, which carries out multiple substitutions in a text using the "regular expressions", much more powerful than the simple search / replace.For details and the regular expressions syntax, see the file:///C:\regexfilter\README.html after installation.
To launch easily regexfilter (it is a filter without GUI) I will use the potential of Notepad++, because it has features not found in other editors.
To make it even easier, I use systematically the three extensions ".nc", ".ngc" and ".gcode" to distinguish the various types of files:
.nc: initial files, from StickFont and Inkscape,
.ngc: modified files for CAMotics,
.gcode: modified files for Repetierand I associate the "nc" files to Notepad ++ the ".ngc" files to CAMotics and the ".gcode" files to RepetierHost.
So using Windows Explorer just a click (double click) on the file to open the correct application.
5.1 Installation:I make reference to a standard PC Windows 10.
Note for other OS: regexfilter is in Java, so it can be used in all OS. For not-Windows PCs, you need to adapt doFilter.BAT (e.g. write a dofilter.sh), then plug it into a suitable directory (e.g. usr / bin) and then add it (see steps 6, 7, 8, 9) to the menu of Notepad ++.You can also set the associations based on file extensions (see step 11) as required by the OS in use.
1. If it is not already on the PC, download and install Notepad ++ from https://notepad-plus-plus.org
2. Launch Notepad ++ and install the plugin NPPexec (menu: Plugins / Plugin Manager)
3. Unzip the file regexfilter.zip in C:/. The directory regexfilter is created, and the main file is C: \ regexfilter \ regexfilter.class, used by C: \ regexfilter \ dofilter.bat
4. Java verification - 1Regexfilter has been tested with Java version 1.7 (and 1.8) If your version of Java is earlier you should upgrade from https://www.java.com/it/download/ The Java version test can be done online: https://www.java.com/it/download/installed8.jsp (also possible from Control Panel / Java or from the prompt: >java.exe -version).
5. Java verification - 2.Launch "Command Prompt" and write “Java”, then enter.If you see the Java instructions: all okay, you can continue to 6. If you read a message like this:
you must look for java.exe path (on my PC is in C: \ Program Files \ Java \ jre1.8.0_66 \ bin \ java.exe) and modify the file C: \ regexfilter \ dofilter.bat using Notepad++ (Notepad does not fit).
6. Add new commands to Macro menu in Notepad ++.
Launch Notepad ++ and setup the first tool as follows:
"java" is not recognized as an internal or external command, an executable program or a batch file.
In Command(s) write (or copy / paste) the following three lines:
SET local OUTFILE = $(CURRENT_DIRECTORY)\$(NAME_PART).gcodeC:\regexfilter\dofilter.bat StickFont_3drag "$(FULL_CURRENT_PATH)" "$(OUTFILE)"NPP_OPEN "$(OUTFILE)"
Press the SAVE button and write the name (internal) of the command:Script name: StickFont 2 3dragPress again the button SAVE and then OK to exit the pop-up.
Back in Menu: Plugins / NppExec / Advanced Options:
In Associated script, choose the command just entered: "StickFont 2 3drag"
In the Item name enter the name used in the menu, eg "StickFont -> 3drag"
Click Add / Modify, the new command will appear in the Menu Items.
Note: You can delete commands by selecting Menu Items, and then Delete button. To change the position of the selected command in the Menu Items use the buttons Move up, Move down.
Close using the OK button
As required, quit and relaunch Notepad ++.Verification: In the menu macro is the new command.
Repeat the above steps for the other three commands (commands are similar, it uses 4 different DAT files in C: \ regexfilter) as follows:
7. Command(s):
SET local OUTFILE = $(CURRENT_DIRECTORY)\$(NAME_PART).ngcC:\regexfilter\dofilter.bat StickFont_CAMotics "$(FULL_CURRENT_PATH)" "$(OUTFILE)"NPP_OPEN "$(OUTFILE)"
SET local OUTFILE = $(CURRENT_DIRECTORY)\$(NAME_PART).gcodeC:\regexfilter\dofilter.bat Inkscape_3drag "$(FULL_CURRENT_PATH)" "$(OUTFILE)"NPP_OPEN "$(OUTFILE)"
SET local OUTFILE = $(CURRENT_DIRECTORY)\$(NAME_PART).ngcC:\regexfilter\dofilter.bat Inkscape_CAMotics "$(FULL_CURRENT_PATH)" "$(OUTFILE)"NPP_OPEN "$(OUTFILE)"
10. Verification:In the Macro menu of Notepad ++ they should appear the four new commands just entered.
11. AssociationsFacilitates operations to associate the Open command for .nc files with Notepad ++:In Windows Explorer, select a file with the extension .nc, then click with the right mouse button ( you can find such files in C: \ regexfilter \ examples \ )Click Open With, then choose “another app”.In the pop-up window choose Notepad ++. If it is not present, choose “another app” yet, and search for the file Notepad ++. exe (e.g, C: \ Program Files \ Notepad ++ \ notepad ++. exe).Also select: “Always use this program to open files .nc”.Click OK to finish.
Repeat the above steps to associate:
.ngc files with the program CAMotics (e.g.: C: \ Program Files (x86) \ CAMotics \ camotics.exe)
.gcode files with the program RepetierHost (e.g.: C: \ Program Files \ Repetier-Host \ RepetierHost.exe)
5.2 Use:Open a file .nc in Notepad ++ (just double click it in Windows Explorer).
Select in menu / Macro one of four new commands to run the required filter.The filter reads the input file selected in Notepad ++, applies the changes described by the regular expressions in the .dat file, and writes an output file.
The output file is in the same directory and has the same name as the input file. Only the extension will change: .ncg for CAMotics and .gcode for Repetier.The output file is automatically opened in Notepad ++ to check the result, or for further manual editing.
Note:• If the output file already exists, it is overwritten without warning.• If the input file and output file are the same, the input file is deleted.
Clicking (double-click) on a file .ngc, the simulation (CAMotics) must start automatically.
Clicking (double-click) on a file .gcode, Repetierhost must start automatically.
5.3 Modifications:
• To edit the files that contain the requiered regular expressions (the four files C: \ regexfilter \ xxxxxxx.DAT) use Notepad ++.
• The regular expression syntax and the syntax of the DAT file is described in f ile://C:/regexfilter/README.html
• The Java source files of regexfilter are in c: \ regexfilter \ src \ src.zip
Note 1 – Use the point as decimal separator.Many countries uses the comma (“,”) as decimal separator.Some programs do not take into account local settings and expect instead the period (.).In particular, the G-code for Repetier or CAMotics uses period as separator, while some of the programs examined generate commas (from local setting).You can change the Gcode using an ASCII editor and changing all the commas (,) in points (.), But when this is not possible or desirable we can proceed in another way: to get numbers that use the period (. ) as the decimal separator we must change just temporarily the settings for the local language.
HOWTO:1. Go to Control Panel / Clock, Language and Region / Language - Change date, time or
number formats.or:Control Panel / All Control Panel Items / Language / Change date, time or number formats.
2. In Additional settings choose Decimal "." (Period).3. Remember at end to restore the local standard.
Note 2 – Font True Type
True Type fonts always consist of one or more closed paths, with the interior filled.For the incision lines are used instead.Using for engraving normal TTF fonts, it is used the outline of the glyph and then you always get a double perimeter inside / outside.However, there are special TrueType fonts designed just for cnc engraving, for laser cutter etc.
TTF stickThese special TTF are formed by a closed line that runs through the glyph twice, thus obtaining a route suitable for linear incision.PRO:
• Stick fonts are TTF fonts standard, usable in every application
• There are versions in 1 line, 2 lines, 3 lines ... to simulate the filling of wide areas
AGAINST:
• The double passage of the bit doubles the running time and can fail.
In the figure, you can see how looks a Stick fonts (Inkscape):above: Filling: yes, outline: No (Objects menu / Fill, Outline)under: Filling: no, outline: yesThis font are also called "Single Line Fonts with 2 lines". example
Single line open pathThese TTF fonts contain closed paths which must be "open" with the elimination of the last segment. This additional step can be performed in a vector graphics program, after transforming the text in graphic objects and after ungrouping objects. For Inkscape exists a special automatic extension reopenSingleLineFontIn the figure, appearance of a single line open font (Inkscape):
1. filling: yes, outline: No (Objects menu / Fill, Outline)
2. filling no, outline: yes
3. After removed the closing segment
example
PRO
• true font with single line
AGAINST:
• Requires an extra operation executable only in a vector graphics program
• After cutting we get paths, not more fonts. (I.e., the cut must be the last action to be able to take advantage of "text" features in the graphics program)
• Few fonts in the Web.
Note 3 – G-code, Start and EndNot all G-code are supported in the simulator or in 3Drag + Repetier, or by various software. Also it can be interpreted differently in different environments (see Manual RepRap G-code).For example, the simulator correctly interprets "G00 X4F100", but this gives an error in Repetier, who always requires spaces: "G00 X4 F100".
This involves, in general, the need for many checks and modifications to the code produced by different SW, as before indicated in each case.
START 1:For the required functionality (see), after placing the pen (bit) 1 mm (bit: 1mm - cutting depth) over the starting point, we have:
G90 absolute coordinate mode (perhaps superfluous, is the default) G92 X0 Y0 Z3 the current point assumes coordinates (0,0,3)
END 1: My pen (bit) in HOME is left of the bed, but lower, and every time I do not want to calibrate the zero Z axis. This sequence (which also I use by hand-in Repetier) prevents damages.
G28 X Home of the only X axis G28 Y Z Home axis Y, Z
START 2If you want to always start from home to reach the piece, you can do the following:
• Using Repetier place with the pen (bit) at the start of engraving.• Get down with the pen (bit) until it touches (use a piece of paper: it must be removed
without breaking).• Lift the pen exactly 1mm, (bit: 1 mm - engraving depth)• We call AA, BB, CC the coordinates X, Y, Z that we read on Repetier• If there are no obstacles, we can use CC + 5mm as Z height for the rapid moves.
We call this value SS• Starting from HOME the code could be:
G90 absolute coordinate mode (perhaps unnecessary)G00 ZSS F100 lifts the pen (bit) to travel heightG00 XAA YBB moves to the starting pointG00 ZCC down to required valueG92 X0 Y0 Z3 the current point assumes coordinates (0,0,3)
END 2Sometimes you may want to end on the same starting point, for example to make a second pass at depths greater:
G00 X0 Y0 Z3 back to the starting point, coordinates (0,0,3)
References:
CAM 2, 2.5, 3:The text incision does not exhaust the panorama of CNC applications of 3Drag:
• Good start point for CAM sw: http://www.shapeoko.com/wiki/index.php/CAM• Basic workflow 2D
Inkscape:I did not use Inkscape before of these tests, but it seems interesting and deserves attention:
• Brief notes for new users • InkscapeHowto
Gcodetools:Gcodetools also, in my opinion, deserves attention, for example to make incisions in low relief from photos, etc.
• Inkscape and Gcodetools Tutorial: Cut Out a Shape ,
• Spanish manual with instructions for PCB,
• Generation of G-Code: InkScape and G-Code plugin
Fonts
This seems to be a critical point, with relatively few viable solutions. I think I will try to develop it soon:
• font TTF stick download.• single line open font TTF download.
• Resources: free font TTF: Google, Fontspace, 1001fonts, daFont• Editor for TTF fonts: FontForge• Tutorial Single line open TTF fonts using Inkscape• Font stick sell: 10$-100$ (esempio)• The sw SFEdit by Roland (included in "Dr. Engrave") should transform the TTF windows
fonts in Stick fonts, but it is only distributed with the HW Roland (sic).
G-code• Manual RepRap G-code
Materials, cutters and speedThis is one area where I must do quickly experience for better results
• ShapeOko good start point.
3Drag• Collection of Add-on for 3Drag using Fast Clamp
Windows 10• To get back a programs menu with all applications, two-level, I installed it and find it very
