Category:Mendel Rostock Development

Besides the re-design of existing there was the design of new components for Mendel Rostock (modified in Jena electronic things). With this 3D printer we present you an optimized system and show you in this article the improvements and modifications compared with the previous model.

Framework

The first improvement idea of the system dealt with the framework. In order to the prevent warping of the frame, the bottom, top and side panels were strengthened. The thickness of the bottom and top plate of 12 mm were extended to 15 mm. As sidewalls 12 mm strong plates were selected. A second supporting sidewall and internal angle in the frame should also provide additional stability. The side walls serve not only the stiffening of the system but also the attachment of subsequent components such as the electronics. Figure 1 shows the modified framework from the back view.

Figure 1: The Framework

End effector

The end effector consists of penholder, platform and hotend. The penholder is the holder for the hotend in which the filament is heated and from which it will be extruded. Originally the penholder for hotend's is designed with an external diameter of 10 mm (see Figure 2).

Figure 2: Der Original Penholder

Due to the fact, that the thermal barrier of our Hotend's has a diameter of 16 mm, the redesign of the penholder was necessary. The new penholder was designed in a way so that the old platform could be used (see Figure 3) for attachment of penholder and printer arms.

Figure 3: The platform

So only one component had to be redesigned. The new penholder (see Figure 4) consists of a simple plate with a hole with the size of 16 mm for the hotend. In addition, the hotend will be fixed by two horizontal introduced screws.

Figure 4: The modified penholder

On Figure 5 a standard peek barrier will be figured.

Figure 5: A standard peek barrier

In Figure 6 the modified peek barrier for the Mendel Rostock will be displayed. In the process the standard barrier was slightly extended, in order to introduce on the top a thread.

Figure 6: The modified peek barrier

Here a metallic hose coupling is screwed (see Figure 7 & 8).

Figure 7: The metallic hose coupling

Figure 8: The metallic hose coupling from below

Figure 9 shows the fully assembled end-effector.

Figure 9: The modified end effector

Carriages

Carriages are cars, which are located on the LM8UU camps on the silver steel shafts. Originally, they are driven by a closed belt (GT 2). We use T2.5 endless belt. Consequently, we had to use other pulleys and to larger the carriage design, in order to fix both ends of the belt. Important for the redesign, however, was the idea was to provide an opportunity, so that in the event of extension of the belt, they could tighten them. In this way, the attachment of always new timing belt should have been avoided. For this purpose an attachment is mounted to the cap, which contains the toothing of the belt as notches (see Figure 10).

Figure 10: left: new carriage, centrical: mounting of the toothed belt, right: belt clip with teeth

Jaws

Jaws are the ends of the printer arms, where the arms, the end effector and the carriages are connected together. These were modified and made thicker. Figure 11 shows the original version.

Figure 11: old jaws

On Figure 12 the modified and so more powerful version will be shown.

Figure 12: new jaws

This type of Jaws we need, as we have decided to produce aluminum rods.

Extruder

The feed unit of the extruder through which the filament is guided into the hotend had to be redesigned. In Figure 13 the initial extruder will be displayed.

Figure 13: The old extruder

After several extrusion tests with the original Rostock extruder, we found this not mature. For this reason we decided to change it. We modified an original wade extruder and brought a recess in the side for hotend. Here a mother is positioned, in which a metallic hose coupling is screwed. Figure 14 illustrates the modified wade extruder.

Figure 14: The modified extruder

The choice of another filament screw, is an innovation compared with the original. Figure 15 demonstrates the filament screw that we use for the Mendel Rostock.

Figure 15: Our filament screw

It is the standard filament screw that we mount extruder in Wade and Greg Wade. On Figure 16 the modified and already installed wade extruder will be illustrated.

Figure 16: The modified wade extruder (already installed

Roll mounting

In order to save space for the filament roll, the holder was mounted on top of the printer framework. In order to distribute the weight non-critical, the attachment was carried out as far as possible at the edges, where the panels stabilize the printer additionally (see Figure 17).

Figure 17: The roll mounting

If you have questions about the structure or the printer or the functioning in detail, please contact us via E-Mail to [email protected] or by phone: +49 (0) 3641 50 96 06. The modified RP-parts for Mendel Rostock are in Thingiverse as .stl files uploaded. The complete kit of parts for Mendel Rostock is in our Shop available.