lully the 3D printer

Lully is the BTU Lab’s live-in 3D printer, located in ATLAS room 105. All lab members are allowed to use it! We provide filament, but encourage you to bring your own as our supplies are limited.

Our printer is a Lulzbot TAZ 5 with a single-extruder hexagon hot end. It has a 290mm x 275mm (11.4in x 10.8in) build plate and can print about 250mm (9.8in) vertically. It runs off of Cura Lulzbot Edition, which can load .stl files. For a list of materials you can print at the lab, see our 3D Printer Materials page.

Getting Started

Before you come in to print, make sure that the printer is available for that time slot! A link to the 3d printer’s calendar is taped to the printer table. If you have no idea how long your print will take, estimate at least 4 hours (we’ll go over print time estimation later on in the guide).

Once you have a .stl file to print (we’ll have a guide on how to make a file soon), the first step is to load it onto the 3D printer computer. For files from a website like Thingiverse that’s as simple as downloading it, but if you made the file yourself you may want to bring a flash drive or email it to yourself. With that out of the way, the next step is to open up Cura – the updated version with the square logo works best, not the old version with the cube logo! It should be pinned to the far right side of the task bar.

Once you’ve opened Cura, visit File>Open to load your .stl file. Cura should load a preview of the model, and you can use the buttons in the bottom left corner in order to resize and rotate.

Loading your Filament

This portion of the guide assumes that the material is PLA; for other materials, please see our 3D Printer Materials page and substitute the bold for your material. Skip this step if your material is already loaded into the printer.

Before you touch the filament, visit the Prepare tab in Cura, towards the top of the window. On the right, you’ll be able to enter temperatures (Celsius) for the head and the bed. Set the head temperature to 205°, and the bed temperature to 60°. On the printer’s LCD, you should see two icons – one showing the head, and one showing the bed. Above each is the goal temperature, and below each is the actual temperature. Wait until the actual head temperature is at least 180° (Don’t worry about the bed temperature just yet).

Now, find the thumb screws on the left of the print head, and unscrew them until you’re able to push them up and pop open the filament feed. If there’s filament already in the printer, then now is the time to pull it out. Snip off the melted end with wire cutters, and then tuck the end into one of the holes on the reel for storage.

Now, feed the end of your new filament into the nozzle. Try your best to push it through until some of it comes out – you might have to push kind of hard. Keep pushing it through until you see the color of the new plastic, as some of the old plastic may still be stuck in the nozzle. If the plastic won’t come out, then that’s alright! We can fix that later.

Push the side of the head back up to fit around the filament, and then pop the piece with the thumb screws over it and screw them back in. They can be loose as long as they’re tight enough to hold the filament in place. If you couldn’t feed the filament through in the last step, hit the extrude button on the Prepare tab until you can see it come through. Make sure you remove any excess filament with the wirecutters before continuing!

Print Settings

Now that you have your material in the printer, the next step is to tell the program what material you’re using! In the menu on the right, make sure the Category field is set to “all”, then set the material just below it. Polylite PLA will do if you’re using any kind of PLA. You’ll also want to tell the printer what kind of print you want to do: high speed, standard, or high quality.

High Speed Fast, but not detailed. Great for quick prototypes or parts that don’t need to be pretty
Standard The perfect mix of quick and detailed
High Quality Slow, but extremely detailed with a smooth surface. Best for final products and small, high-detail models

Leave the print settings as Recommended unless you know what you’re doing. 20% infill is usually fine unless your model specifies a different infill.

Support should be checked unless the model is specifically designed to be printed without support, or you’ve added support in another program. Support prevents the printer from trying to print in midair by building a scaffold that can be removed later. It’s a good idea to rotate your prints in ways that avoid support, if you can!

Build plate adhesion can vary. A skirt is just a small outline of filament around the print area, to ensure that the filament is going through. A brim is several outlines attached to the base of a print, similar to the brim of a hat. It’s best used for prints with small bases that might come up from the bed, ruining your print. Finally, a raft is a several-layer platform that can be used for particularly tricky bases and prevent warping in the first few layers. Rafts aren’t used very often, because they’re big and harder to remove!

Once you’ve finished messing with the settings, check the time estimation in the bottom left corner. If you haven’t already booked time, now’s your chance to do so! The link to the printing calendar is taped to the 3D printer table. Book an hour or two extra just in case, as it tends to underestimate.

Starting the Print

Congrats – you’re ready to print! Hit the big green button in the bottom corner. Cura will swap over to the monitor tab, and your print will begin. It may take a minute to heat up first!

Keep an eye on the printer for the first several layers, and don’t leave the lab for the first 30 min-1 hour. Most print errors happen in the first portion of the print, and it’s important to stop them as early as you catch them. Otherwise, your print will be destroyed and our printer might be damaged! After the first portion is done, you can leave and come back later to pick up your print, but make sure you leave your name and email, just in case something goes wrong.

Removing the Print

Your print is done, and it looks great! Now what?

Take the clam knife beside the printer and wedge it between the print and the bed, at a 45° angle or less. Start at thinner parts and corners, and if it won’t budge, try coming at a different part of the print. Your goal is to pry the plastic off of a bed that’s made to stick, so you’ll have to push hard – just be careful not to pry vertically instead of horizontally, or you’ll damage the bed! The piece may come up from the bed abruptly, so look out and be sure not to pry towards yourself.

Cleaning up a Print

You’re almost done! The last thing to do is remove any brims or supports on your model. Flush cutters or needle nose pliers are usually the best tools to do this. Grab the support material with the pliers and gently tug them off of the model, or alternatively use the flush cutters to cut them away from the surface. For delicate or support-heavy prints, you may have to alternate between both.

Further reading and resources: