Silicone Extruder Assembly

Silicone extruder is the most important component of this project. Since we are using two-part platinum cure silicone material as our ink, the mixer needs to mix both part A and B together before extrusion. When the part A and B mixed and extruded on top of the heated bed the silicone material needed to be cured immediately so that the 3D printed object holds its shape. For that we came up with convective heater mechanism to cure the material in combination with heated bed. On the right handside you can see the illustration of our silixone extruder mechanism.

 

 

 

Let's start building our extruder. Here is the shopping list.

Shopping List

1. Dispensing tip  (as many as you want but we suggest 3 to 5 units)
2. Male threaded pipe: Part number: 51525K318  (you need at least 3 units, feel free to get more units)
3. Shaft seal (1 unit)
4. O ring Part number: 9263K287 (1 unit)
5. Motor (1 unit)
6. Coupler (1 unit)
7. Screws (you need only 2 unit, feel free to get more untis)
8. Voltage regulator (1 unit)
9. Electric cables: I assume you guys have some to connect pur small DC motor into voltage regulator. Regular cables are enough its going to be less than 1A and 12V.
10. M3 screws (this set will be enough)
11. M3 wing nuts (6 units)
12. M4 screw set

3D Printing List

For the rest of the extruder parts you need to 3D print them. We used Formlabs Form 2 as our 3D printer to manufacture our extruder parts with high precision. If you don't have a 3D printer or if you are not able to get the high resolution with the one that you have we suggest you to use Hubs or Shapeways. For extruder parts we suggest you to select clear resin with Form 2 SLA 3D printer. Here are the stl files and resin suggessions for fabricating the silicone extruder parts. 

You can download the stl files of the parts that needed to be 3D printed from the zip file called "silicone_extruder_stl_files.zip" which is attached to the end of this page.

Here is the list of the parts and resin preferences. 

Parts to 3D print

Part name	Resin preference
Bottom_Nozzle	Clear Resin
Upper_Nozzle	Clear Resin
Upper_Seal	Clear Resin
Mixer	Clear Resin
Extruder_mount_anet_a8	Grey Resin
Pillar_anet	Grey Resin
Heaterholder_right	Tough Resin
Heaterholder_left	Tough Resin
Wing_joint	Tough Resin
Wing_arm	Tough Resin

 

 

 

 

 

 

 

 

 

 

 

Assembling the extruder

After collecting the necessary equipment and 3D printing the required parts it is time to assemble. Here is a presentation of the extruder parts in the order of assembly from bottom to top. 

According to this repsentation here are the steps of how to assemble the extruder:

• Step 1: Get the dispensing tip and connect it into male threaded pipe
• Step 2: Connect the male threaded pipe into bottom nozzle. Make sure that you tapped the 3D printer part where the male threaded pipe is going to attach with 1/4-28 tap.
• Step 3: Insert the mixer into bottom nozzle
• Step 4: Connect the O ring into upper nozzle and merge the upper and bottom nozzle while encapsulating the mixer part
• Step 5: Connect male threaded pipes into upper nozzle and again make sure that you tapped the 3D printer part where the male threaded pipe is going to attach with 1/4-28 tap.
• Step 6: Insert the shaft seal
• Step 7: Insert the upper seal and put the screws in. Make sure that you tapped the 3D printer part (bottom nozle) where the male threaded pipe is going to attach with 1/4-20 tap.
• Step 8: Connect the coupler into mixer via set screws
• Step 9: Connect upper nozzle with pillar_anet with M6 screw and make sure you tapped the 3D printed pillar part
• Step 10: Insert motor and connect the motor shaft into coupler.

Also we have prepared a youtube video for how to assemble the extruder and start the mixer. Here is the youtube video: 

After completing these steps it is time to attach the heat wing arms as seen in the picture down below and in the video. Use your M3 screws with the wing nuts. To learn how to attach this silicone extruder into Anet A8 3D printer base please refer to our youtube video:

 

Power connection of the mixer

After assembling the silicone extruder into our 3D printer here is the last step to power the mixer. First solder two cables into our mixer motor as seen in the figure down below (A). Then connect those cables into our voltage regulator circuit's output socket (B). Later, connect other 2 cable from voltage regulator's input socket into 3D printer's power supply (C). The final connection can be seen in (D). Good thing about this regulator circuit is you can on/off the mixer with the button on it. (on/off operation is shown in the youtube video). Also you can arrange the speed of the mixer by changing the voltage output of the cirucit. 

After completing this section, let's move into the our heater system's assembly.