Bowden Extruder

prusaprinters

<p>This is a quite simple bowden extruder, albeit for a very specific mounting case. I couldn't find a ready-to-use solution so I designed this one from scratch.</p> <p>My 3D printer is placed in an Ikea housing (Stuva box with glass door) on which I have several of my filament dispenser boxes (<a href="https://www.thingiverse.com/thing:2754979">https://www.thingiverse.com/thing:2754979</a>). The filament ix fed through the top into the direct drive extruder. This is working fine but I always wanted to try a bowden extruder, just to get familiar with it. This extruder is specifically designed to be mounted on top of the housing, as shown in the images.</p> <h4>Update</h4><p>I added a bowden extruder body for the original Prusa i3 MK2/S. It's basically the original part with the motor mount trimmed away. I also added an additional hex nut to keep the top mounting spot (the second one I added was a mistake, ignore it ;-) ).</p> <p>Since the extruder uses a different drive gear I had to recalibrate the steps/mm for the extruder motor. You can do this with the M503, M92 and M500 commands. There's some excellent documentation on the Marlin website. For the Prusa i3 I adjusted the extrusion from 161.3 steps/mm to 142.1 steps/mm.</p> <p>Furthermore I modified the retraction settings in the Slic3r settings to 5 mm retraction length and 100 mm/s retraction speed. This just a start though and will probably be refined later on.</p> <p>The first print is shown in the images above. I really did not expect it to work so well right out of the box. It still needs some fine tuning though. It appears there's some over-extrusion and the bed height offset is not quite right.<br/> Another issue I noticed is the extruder motor skipping some steps on high load situations. I used a different motor with higher torque, so maybe the current settings are inappropriate. I probably will just switch to the original Prusa motor.</p> <p>Other than that it works suprisingly well. :-)</p> <h4>ChangeLog</h4><ul> <li><p>2018-03-10<br/> Original Prusa motor and drive gear mounted. No more stalls or skipped steps, works fine. Fine-tuning of Slic3r can begin...</p> </li> <li><p>2018-03-03<br/> Extruder assembled and tested.</p> </li> <li><p>2018-03-02:<br/> Original upload</p> </li> </ul> <h3>Print instructions</h3><h3>Parts list</h3><p>The extruder uses/requires the following parts:</p> <ul> <li>1 E3D Hobb-Goblin 5mm drive gear</li> <li>1 E3D groove mount bowden adaptor</li> <li>1 quick connector for Teflon tube</li> <li>1 push fit M5 thread</li> <li>1 625 ball bearing</li> <li>1 5x14 mm cylinder rod</li> <li>2 M6x40 screws</li> <li>5 M3x35 screws</li> <li>1 M3x40 screw (+ spring and washers)</li> <li>2 hex nuts M6</li> <li>1 hex nut M3</li> <li>1 square nut M3</li> </ul>