PrintrBot Plus

Printrbot / printrbot.com / Available in the Maker Shed

Price as tested $999 assembled
Print volume 8″×8″×8″
Heated bed? Yes
Print materials ABS and PLA
OS supported Linux, Mac, Windows
Print untethered? With SD card, initiated from computer
Open-source hardware? Yes, noncommercial
Open-source software? Yes
Printer control software Repetier-Host
Slicing software Slic3r with SFACT profiles

Lincoln, Calif.-based Printrbot, founded by Brook Drumm in 2011, operates with the goal of making 3D printers affordable for every home and school (see “Generation 3D,” page 30). The Printrbot Plus, the grandest of the company’s three machines, is a great printer for the value-minded maker — it’s fast, has a large build platform, and only costs $999.

It’s also a little tricky to get dialed in, so if you’re looking for something that doesn’t require any tweaking out of the box, this printer is probably not for you. But once the settings are fine-tuned, the Plus prints similarly to machines twice its price.

Upgradeable

One of the Printrbot Plus’ attractive features is its upgradeability, great for people who aren’t sure if they want to spend money on options like multiple extruders or a higher-quality bed. Having the ability to update the printer also future-proofs it by allowing new hardware to be added as it gets developed.

Support Your Objects, Level the Bed

In testing, the printer seemed to struggle on very precise parts without any support, but by using support structures and by reducing overhangs, we were able to get our prints accurate to about 0.15mm.

Using PLA gave consistently better results than ABS, which had the unfortunate tendency to peel off the bed. We had our best results with the Printrbot Plus by leveling the bed, heating it to at least 80°C and the extruder to 240°C, and encouraging print adhesion by putting a thin layer of ABS goo on the bed. (ABS goo is easily made by mixing small bits of ABS with acetone.)

Easily Correctable Over-Extrusion Issues

We noticed some overextrusion, even with the motor movement settings (aka EEPROM settings) properly calibrated. These settings make the printer move a specific distance when defined, and will change if gearing is modified or a motor is replaced. On a Windows computer, these settings can be found by clicking Config, then clicking Firmware EEPROM Configuration. We found that adjusting the filament setting to 0.1mm greater than its actual diameter eliminated these problems. Once the printer’s settings were configured properly, it worked well.

And what’s not to love about the 8″×8″×8″ maximum build volume, larger than that of many other desktop 3D printers?

Untethered Printing Possible

The Printrbot Plus is able to print untethered, although it’s not a completely straightforward process. The built-in SD card reader can store files and allow users to unplug their laptops after a print has been selected. These can later be reconnected to regain control of the printer; you can then pause, stop, or modify the print. This feature works well for longer prints.

Printing Untethered: The Missing Chapter

While the Repetier-Host software has built-in SD card support, it’s slow and buggy; don’t use it to transfer your G-code. Instead, unchain your computer with the following steps.

• Use your laptop’s SD slot or a card reader to copy the G-code directly from the computer to the card.
• Install the SD card into the printer, and connect the laptop.
• Select the file to print in Repetier from the SD card manager, and initiate printing.
• Click Disconnect in Repetier and unplug the USB cable. The printer will continue to run.
• To resume control of your bot, simply plug the laptop in with USB and click Connect.

Conclusion

Overall, the Printrbot Plus is great for experienced makers and people who enjoy a lot of tinkering — it takes some fine-tuning but gets good results.
And at just $999, there’s a huge value here. We recommend the Plus to anyone with spare time to spend calibrating the settings, and who wants a machine with a large build volume that can support multiple materials.

Primo features

• Large bed for a printer of its size
• Supports both PLA and ABS printing

Who’s It For?

• Tinkerers with more time than money

Pro Tips

• Printrun works better than Repetier-Host for uploading G-code and printing from an SD card.
• For printers released before the cast-aluminum bed was added, we found that placing a thin sheet of glass with painter’s tape on top helped limit bed warping.

This review first appeared in MAKE’s Ultimate Guide to 3D Printing 2014, page 86. Check out the full issue for more!