Projects:3D Printer

From 57North Hacklab

Revision as of 23:19, 11 June 2019 by Andyg (talk | contribs)

3D Printer
Description Kossel Mini
People User:Nordin
Theme Infrastructure
Website http://octopi.local or
Status Finished

About the Space 3D Printer

For the raw specs, see the original Ebay Item (webpage snapshot). It is a RepRap kit Kossel Mini.

It can print items up to 200mm in diameter and 210mm in height.

OctoPi and the OctoPrint Interface

The space 3D printer is connected via USB serial to a Raspberry Pi V3 running the Octoprint print service, hosted on a custom Raspian build called Octopi. Using this, no PC is needed to run the printer as all features can be accessed via a webpage user interface.

How to 3D print an STL

The Octoprint UI requires a user login. The shared account to access the printer is username:printeruser, password: printeruser.

STLs can be uploaded to the device and stored for reprinting. Users should upload their files to their own user folder if printing for their own projects.

Once uploaded, users will need to convert their STL files into g-coded (*.gco) files. This conversion is called 'slicing' and a slicing engine has been added to the web interface using a generalised slicer profile (57N_Default).

Kossel Mini, June 2019

Preliminary Checks

  1. Check the arms are tight and not loose,
  2. ensure there is hairspray on the bed to aid the initial layer to stick to it otherwise
    1. clean the bed with a degreaser like isopropyl alcohol, ensure to wipe it clean afterwards
    2. spray 3 coats of hold hairspray onto the bed to help the print stick.

Making Your Model

We advice OpenSCAD for the model design, ensure you have enough faces on any circular elements, and export as an stl.

Loading to OctoPrint

Using OctoPrint

  1. look at the files section on the left, If you Don't have a user Directory create one and put your models in there
    1. Upload your stl into the directory
  2. You should see the model on the right that means you are in the slicer
    1. Turn the model to the orientation you would want it to print using the 3d View.
    2. If the model is not flat on the bed you should Select Advanced->Adhesion->"Raft" at the bottom, otherwise select "Brim" for best bed adhesion.
    3. Now click "Slice it!" button at the bottom to create the gco file.
  3. In the files section you should see a new gco file
    1. click on the Folder icon beside it to load the slice.
    2. in the GCode Viewer on the right, check through the slices.
      1. consider whether the think looks reasonable
      2. or the the shell of the model is thick enough for what you want.
  4. If you are happy Click the print button and see how it goes.

If you have problems look to troubleshooting below, and add any issues you have.

Top tips

When printing small items

For prints with quick layer times (from small areas or thin walls), a slower print time allows your extruded filament to cool and set more before the head returns, preventing the hot head from 'dragging' over weak areas of the print, marking or detaching them. You are recommended to either:

  1. Print a second part away from the first print to increase travel time; or
  2. Slow down the print speed as detailed below

When printing any item that detaches from the buildplate

For a good print, a firm wide-contact footprint on the build plate is needed. To better achieve this for parts that have a light contact area (such as a raft), it is recommended to slow down the feed rate and flow rate using either the setting in the slicer engine or the live controls tab on the Octopi UI. For the latter, drop both the sliders to their lowest level and click the buttons below the sliders to set the new values. You will immediately notice a slowdown in printing. Speed this up again after the first few layers.

Common Problems

State: Offline (Error: MINTEMP triggered, system stopped! Heater_ID: bed - Printer halted. kill() called!)

Solution: Warm up the bed with the heatgun then press the connect button on the web interface and it should go away