G199 or how to 3d print a logo on existing STL files

The problem

Logo with 2 different Filaments
Logo with 2 different Filaments

Sometime you want to print you logo or some text on your 3D object with different filament but you only have a single head printer and don’t want to spend all the time sitting next to your printer to wait for the right moment to manually pause the print and change the filament. Like the Motionlab logo on the picture. For sure you could print it separately and glue it on the main printed part but specially with text it’s a lot of tiny parts to take care of and align. If you are lucky and have a dual print head it’s not a problem but there is also a way to do it very simple with a singe print head by editing the G-Code file and add G-Codes by hand.

The solution

There is a G-Code named G199. Regarding to Craftware the purpose of the code is “G199 pauses the print immediately, and moves the head to X0, Y100. (this is the command the LCD screen uses)”. So by adding this code by hand the printer stops printing and moved the head to the side. After changing the filament (and also extrude some more by hand to make sure the printer is ready) you can press “continue” on the printer display.

Prepare the SVG file

If your logo is already in SVG you are lucky. Otherwise try to convert it to SVG and make sure it’s in connected objects. If you need some geeky stuff I can recommend Geeksvgs.

Use Fusion360 to create the STL logo file

Fusion360 insert SVG
Fusion360 insert SVG

In Fusion360 use Insert -> Insert SVG -> Select SVG File to open the SVG file on a Sketch. Resize and stretch it as you like or the dimensions dictate.

Next step is to extrude the logo to a 3D object. This can be done simply by “Stop Sketching” and then press “e” for extrude. Select everything by drawing a frame with your mouse. Unfortunately fusion has no idea witch part of the logo should be extruded and witch not. Press and hold CTRL and deselect the inner parts of the logo. For example the circle in the “o”. I recommend extracting 10 mm even if you only want to rise the logo by 4 mm.

As the single objects are not connected fusion creates several bodies instead of one.

Save single STL
Save single STL

A single STL file with all Bodies included at the right position can be exported by pressing the Component name and press the right mouse button.

Combine both STL in your slicer

Now as we have two STL files we can load them both at the same time in our slicer (no matter witch one). Position your logo at the right place, scale it and change the z access offset accordingly to your needs.

Combine STLs
Combine STLs

As we extruded the logo 10 mm there is enough space to play around. Make sure at least one mm is submerged in your main body.


Manually edit the gcode to add the pause sequence

Find the right Layer
Find the right Layer

Now we need to find the right place in the G-Code itself. Our slicer can help us with the preview mode. The best layer is the second one after the main body is done and the logo starts to be printed.

Mark down this layer and open the G-Code in your favorite text editor. All slicers I used always make nice comments in the code to find the light position. Search for “layer nnn” and add the “G199” statement.

G1 X120.290 Y97.291 E0.0407
G1 X117.699 Y96.872 E0.0884
G1 X115.696 Y96.511 E0.0685
G1 X113.803 Y94.618 E0.0901
G1 X113.662 Y94.477 F2400
G1 E-1.5000 F1800
; layer 156, Z = 39.000
; inner perimeter
G1 X114.840 Y96.357 F4800
G1 Z39.000 F1000
G1 E1.5000 F1800
G1 X111.737 Y95.763 E0.1064 F2400
G1 X110.227 Y95.491 E0.0517
G1 X108.129 Y95.141 E0.0716
G1 X106.311 Y94.873 E0.0619
G1 X105.294 Y94.746 E0.0345
G1 X104.465 Y94.666 E0.0281
G1 X103.842 Y94.638 E0.0210



Just print the G-Code as you always do. As soon as the printer reads and process the G199 comment it stops printing and moves the head to the left side. All heating settings remain the same and you can easily replace your filament and press “Continue” or “GO” on your printers screen. Happy printing.

AstroDIY 3D printed Dobson Telescope

How to print your own Telescope

3D printed Dobson Telescope
3D printed Dobson Telescope

For the last 3 month I worked together with a very good friend of mine (Herwig Diessner aka AstroHD) on a DIY project. The idea started back at the 34c3 conference in Leipzig. Talking the topic “tuwat!” (Do something) serious we decided to 3D print a real size and working telescope. And yes we did it. Tomorrow at the “Tag der Astronomie 2018” we will present our own 3D printed Dobson Telescope.