3d Printers

3D Printers

Our current setup

Here's the setup and what we currently have:

  • Lulzbot TAZ 3 (Formerly a Taz 2.1 but we updated firmware and power supply)
    • Material: 3MM HIPS, ABS, PLA
    • Dimensions: 298mm x 280mm
    • Acrylic Buildplate heated
    • Raspberry PI B attached as printserver using Astroprint web service. http://172.16.2.3 (may be available at http://taz2-printserver.local if using Bonjour service on a Mac)
  • Lulzbot Mini
    • Material: 3MM HIPS, ABS, PLA
    • Dimensions: 158mm x 158mm
    • Glass Buildplate heated
    • Raspberry PI B+ attached as printserver using Astroprint web service. http://172.16.2.2 (may be available at http://mini-printserver.local if using Bonjour service on a Mac)
  • Supplies: (This may vary over time)
    • 2x 1kg Orange HIPS 3MM Filament
    • 1x 1kg Translucent Blue PLA 3MM Filament
    • 1x 1kg Natural ABS 3MM Filament


Intro

Despite what most people think, 3D printing is not as simple as pushing a button and watching the printer make your object. These days 3D printing requires some trial and error, and a lot of patience sometimes. Printing on the Decatur Makers 3D printers also requires some training before you print on your own. If they are not properly prepared, the printers can be damaged easily simply by sending a print job to them. This kind of damage can be very expensive to repair. Reading this tutorial should be a first step. Next, take a 3D printing class at Decatur Makers, or get trained by one of the members who is certified on the printers before printing your first object.

For now, let's talk about the materials used in 3D printing and then each step from planning to printing.

Materials: We are lucky to have two 3D printers which print in almost any medium, from standard PLA to exotic electroconductive carbon filament. Most of the time, though, you're going to print in one of the standard plastics: PLA, ABS or HIPS:

  • PLA = Polylactic acid, is mostly used among 3D printer and normally melts around 210-230˚C. It's rather hard and more brittle than the others, but has more color options and doesn't necessarily need a heated bed.
  • ABS = Acrylonitrile butadiene styrene, is a thermoplastic polymer. It normally melts around 180-210˚C and is more soft than brittle (the counterpart to PLA). It needs a heated bed to be printed on (around 80˚C) and has limited (but strong) color options.
  • HIPS = High impact polystyrene is the material that made your old CD cases and still makes most of your drinking cups. It's the least commonly used material of these three and prints around 240˚C with a medium heated bed plate.

Here's what you need to print something in one of the materials described above:

  • Something to print in .stl format. You can make your own object with a CAD or other editor, or you can download pre-made .stl files from thingiverse.com.
  • A computer (Mac/PC/Linux) running a slicer program
  • A prepared 3D Printer
  • Time

We have a 3D printing interest group. It is the best place to ask for help and get questions answered. It consists of a slack channel and a google group. Request a slack invite to decaturmakers.slack.com or email [email protected]


3D printer rules

  • All the basic rules of the makerspace apply. Be respectful and considerate.
  • No food or drink is allowed in the 3D printer area.
  • Put failed prints and excess filament (e.g. struts) in the box under the printers.
  • New users should go through basic training before using the machines and demonstrate basic understanding and mastery of a simple print.
  • Basic filament costs are covered by membership fees. If you are printing a more substantial project, you are encouraged to purchase a roll of filament and share any extra with the space. If we are running low on filament, please email [email protected] with a specific request (preferable URL, model number, and quantity needed). We may need to revisit the filament policy if it is being abused. Don't be that maker :)

3D Printing, Step-by-step

Step 1. Prepare your print in a slicer program (Cura or Slic3r)

Software

Prepare Print

Slicer programs examine an .stl file, analyze it in horizontal sections (in the plane of the floor), and convert each section to instructions for the printer. They output a gcode file that you then upload to our 3D printer servers over Decatur Makers' wifi.

Two popular slicer programs are Cura and Slic3r. We recommend downloading the versions of these programs that have been optimized for our Lulzbot printers from lulzbot.com. Cura is recommended for beginning users.

The Lulzbot website also has filament configuration files optimized for our printers. There are more configuration files currently for Cura than for Slic3r, particularly if you are printing on the Lulzbot mini.

Download the configuration file for the software (Cura or Slic3r), the printer (mini or Taz 2) and filament type (HIPS, ABS, PLA, etc.) you intend to use. If you don't see the material in which you are printing, or your printer or software isn't supported, you can set nozzle and print bed temperatures manually in Cura or Slic3r (ADVANCED USERS ONLY). The links are in the Software section above.

After you have loaded the proper configuration file, click "Add" and select your 3D Model, which should be in the .stl format.

After your .stl file loads, you should see a preview of your print in the Plater window (Slic3r) or the main window (Cura). At this point you can reposition your print, and rotate or scale.

Because 3D printing involves printing each successive layer on top of another, your print will fail if the object you intend to print has overhanging edges, i.e. parts of the print that hang out in midair with nothing beneath them. To print objects with overhanging features, you must enable support structure in your slicer program (Cura or Slic3r). In Cura, check the Print support structure box. In Slic3r, check the Generate support material box under the Print Settings tab.

When you have finished preparing your print, click Export G-Code (Slic3r) or Save GCode (Cura). This is the file you will send to the 3D printer when you have finished preparing the printer.

RECOMMENDED SETTINGS

Taz 3 ABS filament

  • Slice your stl file with one of the TAZ 3 profiles in Cura.
    • Extruder Temp: 230° C
    • Bed Temp: 80° C

Taz Mini ABS filament

  • Slice your stl file with one of the TAZ Mini profiles in Cura.
    • Extruder Temp: 230° C
    • Bed Temp: 100° C

Step 2. Prepare the 3D printer

Before printing, you must make sure the print bed can move freely and is clean.

Do not add anything to print bed. Kapton tape is not needed with the current printbeds. Hairspray or “juice” will damage print surface. Do not add anything to print bed.

There are Cura plastic profiles available for the mini which generate gcode that will automatically clean the nozzle and level the print bed.

If you need to print to the Taz 3, you may need to level the print bed manually according to this video

https://www.youtube.com/watch?v=EdB8jbXFfns&ab_channel=LulzBot

This is not typically necessary if the printer has not been moved.

If leveling the print bed, make sure you bring the bed UP to the nozzle, in the 3 corners after the home corner, rather than moving a corner that is too high down. This minimizes the likelihood of scratching the print bed with the nozzle.

You can check the level of the Taz 3 print bed by printing the bed leveling calibration gcode file.

Special Taz 3 Preparation

  • Press silver knob on LCD.
  • Highlight Prepare.
  • Press knob
  • Highlight Preheat ABS
  • Press knob
  • Wait for bed temperature to reach 2° higher than desired temperature (see above).

OPTIONAL Taz 3 step:

Prime the extruder. When extruder temperature is reached, extrude 10mm of filament until a little filament comes out of the nozzle.

Special Taz MINI Preparation

OPTIONAL Taz Mini step:

Prime the extruder. Use Astroprint to preheat extruder to 230° C When extruder temperature is reached, extrude 10mm of filament until a little filament comes out of the nozzle.

You are now ready to send your print to the print server.

Step 3 - Astroprint Servers

Our 3D printers are connected to two raspberry pi computers running AstroBox 3D printer server software. You can only connect to them using a computer connected to the Decatur Makers wifi network.

Before you send your print to the server, make sure the area around the printers is free from obstruction, that the print beds of each printer are not blocked by anything - cans of hairspray, laptops, Windex, tools, etc. The print beds must be free to move out from the printer to their furthest extension. Check also to make sure the nozzle rails aren't blocked by anything. The nozzle carriage must be free to move to its furthest extension above and down to the print bed.

After the print area is clear, you may send your gcode file to either the Lulzbot mini print server http://172.16.2.2 (may be available at http://mini-printserver.local if using Bonjour service on a Mac) or the Taz 3 http://172.16.2.3 (may be available at http://mini-printserver.local if using Bonjour service on a Mac)(http://taz2-printserver.local/).

First, open a browser window and direct your browser to the appropriate print server. After you have connected, log in with [email protected] and the password that matches our wifi [NOTE 2016-07-23: This password will be changing shortly].

Click Upload, and select your gcode file. You should include your initials in the gcode filename so we can identify your print on the astroprint server.

After it has uploaded, click the print icon. If you are using Cura with the Lulzbot mini, you will see the temperature change, the filament retract, and the nozzle move to the wiping area for self-cleaning. The bed will then auto-level. All of this takes some time, so be patient.

If you are printing to the Taz 3, you should be able to see the temperature target change, and then watch the nozzle and bed temperatures come up over time. If the Taz 2 starts printing without the temperature changing, or if for any reason you suspect the printer is making an error, cancel the print job by clicking cancel, and troubleshoot your gcode.

Even small print jobs can take a long time to complete, but they can be fun to watch! Be patient!

Step 4 - Removing your print

When your print finishes, the nozzle will retract, and the print bed will move backward. The nozzle and bed will still be very hot. Wait until the bed cools down a bit before you attempt to remove your print.

Wait for bed temperature to cool to below 50° C, then the bed will move forward. Room temperature is better.

Remove print as gently as possible. A sharp but gentle tap on the part should release it.

You may need to use the spatula knife to get under a corner of your print to remove it from the bed. DO NOT SCRATCH THE GLASS/TAPE with the spatula! The glass is very delicate, and scratching it even a little will greatly reduce the life of the printers.

When your print is finished, make sure the nozzle and bed temperatures come down - you can watch it on the print server graphs on your browser.

Please leave the printers and raspberry pi's on for the next user.

Step 5 - Final steps

  • As always, please leave the area you are working cleaner than when you found it.
  • Share your work! Post a picture of your 3D print on our Facebook page or write a blog post about your project. Email [email protected] for more information.

Step 6 - Additional documentation

There are quickstart guides and copies of some Taz 3 profiles on our google drive 3D printing folder.

Still needed: Documentation on how to change the filament.