3D Printer Engraver MOD + Inkscape / Gcodetools
Channel: MakeMeMario
Date: 2017-01-22

Some more Details on the Flexible Shaft Adapter:
-- https://youtu.be/wXw-cywOrY0
-- http://www.thingiverse.com/thing:2056326

The Engraving-Path to Gcode COnversion is done using:
-- Inkscape https://inkscape.org/ 
-- with gcodetools https://github.com/cnc-club/gcodetools extension

__Credits__
__Music:
Eric Skiff -- http://ericskiff.com/music/ Album: “Resistor Anthems”
- “Come and Find Me”
- “Chibi Ninja”

__Further Reading:__
- Toms 3D Printer to CNC Mill conversion: https://www.youtube.com/watch?v=MDz1A1XDOt8


---- Transcript ... sort of ----
Tutorial: Engraving with Inkscape Part 3

0:00 - 0:40
Moin und Glück auf! 
Recently I build something for a friend of mine, where some simple engraving would be a nice addon.   I recorded my first steps and after it turned out quite well I thought it might be worth sharing with you.
This Part of the Engraving with Inkscape tutorial Video shows the process of a first test engraving on wood, using a 3D printer. See my other Videos for Installation of the gcodetools plugin for inkscape and a basic setup with some usefull gcode basics.

0:40 - 1:00
I’m using a flexible Spindle Shaft attached to a Dremel Tool, this keeps the weight on the printplatform low. The spindle is adapted to the printplatform with a adapter I build - plans are attached. 

1:00 - 1:30
First thing was to align the workpiece, in my case a flat piece of wood - parallel to the X Axis on my printbed, It’s kept in place by some double sided tape. ThenI need to find get   Z-Coordinate of the surface height as reference. After homing the printer head, I slowly move it down until the tool is ~1mm above the workpiece. 

1:30 - 2:00
That’s the Z-Reference. X & Y Coordinates are missing to get a reference point which will help me to align the shapes shape in inkscape. Moving the printhead to the lower Y side and to the lower X direction. There is it the Orientation Point.

2:00 - 2:30 
To simplify the process in inkscape I prepared a template for my engravings wit the default tool set in gcodetools beeing “CONE”, this matches the dremel tool I use -- a 1.6 millimeter ball-head-engraver bit and a rather slow feed rate of 200 with a Z-Stepping of 0.1mm. The Orientation points control the final cutting depth, which is 1mm in my case.

2:30 - 3:00
Since this is the first engraving in this setup, I testing my final design with just one path and separate it from the rest just not be distracted too much. 
I create one rectangle matching the size of the wood piece that is already sticked with double sided tape to the printbed. 

3:00 - 3:20
It’s 120 mm by 60 mm big. The X and Y coordinates that I noted down will move the selected shapes lower left corner exactly to the orientation point. Inkscape displays the cursor coordinates as well in the lower right corner. This is quite handy for me to compare printer and Drawing coordinates.

3:20 - 3:50
Arranging the test-path within the rectangle.
To generate the toolpath, select the path in inkscape, open gcodetools extension -- path to gcode. Give a file-name and check output-folder. 
Set the surface height, to your measured  Z-Reference. I go 1mm below to compensate for my offset while finding the reference point.

3:50 - 4:30
After generating the gcode file, I always check the code for being sane:
Checkpoint one is travel height - it should be above the workpiece
First engraving depth - should match Z-Reference
The Number of Steps can be counted by Z-Step iteration
The final Depth.

4:30 - 5:23
Ready to start engraving
Unfortunately I missed first seconds of cutting  
Feedrate is ok, cutting is quite smooth though with some vibrations from the dremel
There was no major fuckup in the whole setup,
 the double sided tape - small pieces - sticked very well to the Blue Scotch tape.
Biggest issue I saw would be a not plane surface height, in that case apply more layers of tape on one side to compensate up to 0.5mm, and be extra cautious with initial Z reference to not crush your toolhead
On the longer final engraving, I paused the process to check the temperature, since my PLA adapter would not cope with higher temperature and the spindle might get loose.