The how-to video begins with a stranger kneeling on the floor at Kevin’s home. Steve Graber, who made the 8-foot-tall Cereberus Gigante printer, is preparing it to print by rubbing alcohol on some blue painter’s tape adhered to the printer bed. The alcohol removes the wax from the tape (although Graber prefers using acetone), so the item will stick really well to the bed as it is printed.
Next you see the size of the printer, and Graber pushes “print.” It takes about 4 minutes for the unit to heat up – when it hits 230 degrees, the print begins.
The 3D printer first lays down a perimeter layer outside the actual print area to let the heated plastic, in essence, do a test lap, making sure all the temperatures are correct.
While it prints, Kevin explains that he and Graber are at Kevin’s house, where they have just installed the Gigante so Kevin can create a sculpture to submit just in time to make a 3D art show submission deadline.
Graber explains that this is the Gigante, a very large deltabot 3D printer. He has been making smaller deltabot printers, including one that Kevin has been using, the Cerberus 250. When Caron asked him if he could make a larger printer, Graber said yes, then figured out how.
All the motors and electronics are on the top of the printer. The carriages are belt-driven. The signals are sent from above and the carriages move up and down to position the print head. The 3D printer is called a deltabot style because it has a series of triangles as part of its design. It’s constantly calculating where the nozzle needs to be.
The entire printer is custom built out of CNC-cut aluminum, although the extruded struts are purchased off the shelf.
You can find plans for smaller deltabot 3D printers on the Internet, but this one is a little more custom and high-end than that. This is the first deltabot printer of this size in the metro Phoenix area, and Graber isn’t planning to create a larger one at this time – it was a little tricky getting this one in the door.
It can print 34″ around and 4’6″ in height.
Graber says Kevin’s 3-foot-tall sculpture will take about 30 hours to print (EDITOR’S NOTE: It took about 24 hours as Kevin increased the print speed slightly). The printer is running much more slowly to begin, especially on the bottom layer, which is so critical. What is the fastest it can print precisely, reliably and beautifully? Graber says the printer will be able to make travel moves at about 500 millimeters per second, which is super fast. The actual printing process will be at about 100 millimeters per second. That’s very close to some of the fastest small 3D printers. The limitation right now is being able to push the filament through the nozzle fast enough. Once Graber resolves that, they’ll be able to get even faster speeds.
Currently, the printer is running at about 15 millimeters per second, especially the first layer. Especially with tall prints, you can get pretty far along and, if the base isn’t secure, the piece can get knocked loose and ruined.
This printer uses 3 millimeter filament, which you can buy on Amazon or from many other sources – it’s very common. In the print assembly, it has a little motor and a reduction gear with a toothed gripper that pushes the filament through.
Says Graber: “It’s really just a glorified glue gun.” With a glue gun, you have to pull the trigger, but this one is automatically fed and very precise, but otherwise …
Graber leaves, and the print continues. Once the bottom – which is really the top, as the sculpture is being printed upside down – is printed about two layers thick, the printer will start creating the walls, which are an inner and outer layer. The sculpture itself is holllow.
The video shows the sculpture growing, through the evening and night and into the next day.
As it gets down to the wire, Kevin starts looking at the 1 kilogram spool of filament starting to run out. With 1 hour to go, the printer has completed 3191 of its 3333 layers. Kevin is hoping he won’t have to pause the print and change to a new spool of filament before it is done.
With 58 seconds left, there are two more layers to go. As it prints, Kevin explains that, once it’s done printing, he’ll pop the sculpture off the print bed, measure and print a base for it from the same material, that he will then glue on the bottom of the sculpture.
The print completes, and the sculpture is done! Kevin thanks Steve and Jacob Graber of Cerebus 3D and Graber Cars for a nicely done job. There are a few more tweaks ahead – like a spool holder – but this is likely the largest 3D printer in Arizona, and may be the largest home model in the United States, and it is printing!
At the end, Caron offers a novel idea for creating 3D printers ….