Pausing the printing process allows you to embed internal components seamlessly. Once you go over this instructable, you’ll be able to add sensors (RFID), hardware (bolts, nuts) and even reinforce your plastic 3d printed part with metallic inserts. Let’s begin!
Step 1: Things You Need
-3D Model with a cavity.
-Slicing Software: Any slicer builds g-code. In my case, I use Craftware since it is a free slicer and provides the control and information needed to get the job done. It is recommended you use a slicer you are familiar with.
-FDM 3D Printer or 3D Hubs printing service.
-Elmer’s white Glue (It will make sure you can 3d print on top of your internals)
-3D printing material depends on the application. In this case, I’ve picked nylon because of its strength.
-Internals: RFID sensors, hardware or metallic inserts. As an example, I’ve picked the insert.
Step 2: Modeling
In order to be able to embed anything within your model, you’ll need to make some room by creating a cavity.
The images show a steering wheel, its cavity and the metallic insert.
In this case, the insert acts as a skeleton which is going to add the strength and stiffness to the nylon body. It is a simple 2D design.
I had the aluminum part water jet cut. Thickness is 5mm.
-Nylon or plastic
body which will provide the overall external shape. As an example, I chose a steering wheel but you could use the same cavity concept on prosthesis, drones, tools or other cool stuff.
Make sure the gap between the metal insert and plastic body is at least 0.35mm, all around. Plastics expand and contract with temperature changes, so a good gap is important.
Step 3: G-Code Manipulation
Watch this step on the YouTube video link attached:
Detailed Written explanation:
The idea is to split the G-Code in two parts. This step is very quick and simple if you follow the steps below.
General idea: Part 1 goes from layer 0 to layer x and Part 2 goes from layer X+1 to the final layer.
For the steering wheel:
Part 1 goes from layer 0 to layer 34 and Part 2 goes from layer 35 to layer 196. Images attached will help you visualize when the printing process pauses. Part 2 starts when the layer containing ‘3D” is printed (Layer 35).
Specific G-code Steps to automatically Pause printing:
-Click the red G1 Save button on the right menu of the Craftware slicer to save the gcode file.
-Once it has been saved, open the G-code on Notepad. Make sure you switch from “text documents” to “All Files” as shown on the image attached.
-Since we need to pause at layer 34, we’ll delete part2 (Layer 35 and up) Go to Edit/Find and Type in: ; Layer #35
-Next, select lines from “; Layer #35” to the last g-code line except the Footer section which tells the printer to home your extruder head and cool everything down. To select the lines faster, hold shift, scroll down and click right next to very last number of the final line. Once you’ve selected part 2 code lines, hit delete and save the file as: Part1.gcode
-For Part 2 G-code, reopen the original g-code to delete the part 1 section. Select from ; Layer #0 to the very last code line of Layer #34. To get to the very last line faster. Go to edit/ Find and type in “; Layer #35”. This will take
you to the very last line of code of layer 34 (See Images below ). In this case, make sure you don’t delete the header section.
-Finally, save this new g-code as: Part2.gcode.
Step 4: 3D Printing
Assuming your printer is warm and ready to go. Upload the g-code and start printing. The printer will stop once
part 1 is finished. Here is where you come in and embed you internal part. Remember to add glue to the top face to make sure the plastic sticks to your internal part.
Once your internal component is embedded with glue on top; start part2.gcode. The printer should start on layer 35 and not layer 0.
When printing large parts; use Elmer’s glue to improve bed adhesion of the first layer. After the entire
process is done, you can remove the bed glass and use water to dissolve the glue and remove the part effortlessly. Let the part dry for about an hour or so.