Many folks are dubious about the utility of desktop 3D printing, especially in regards to size. I mean, how many useful objects can you really print on your desktop? Jim Smith’s answer to that question is: it all depends on the size of the desk.
Jim Smith’s homemade RepRap stands at a 3.5 feet tall, 2 feet deep, 4 feet wide, and has a build volume of 403.00 x 403.00 x 322.70 mm or 15.86 x 15.86 x 12.70 inches. Finished being built in 2010, I don’t know how we could have missed it (even NPR’s covered it). After being exposed to 3D printing as an undergraduate at Rensselaer Polytechnic Institute in Troy, New York, Jim went on to obtain a Masters of Engineering in Mechanical Engineering at Cornell University in New York, where he was a part of the team that built the [email protected] open source 3D printer. He then decided that he wanted to construct his own. So, after he bought “3 matching pairs of brand new 450mm long, THK linear recirculating ball bearings on eBay for a great deal”, he decided that he “might as well make a machine that takes advantage of their long length in order to achieve the largest build area possible.” From there, he went on to construct this monster, which, as of yet, has no name and can, thus, be titled The Creature with No Name. Here it is with the [email protected] on its build platform to show its sheer size:
Despite appearances, the machine actually isn’t a Tim “the Toolman” Taylor version of a RepRap. From what I can tell, it has the same architecture and hardware as other 3rd generation RepRaps. But it’s bigger. Like some RepRaps, this one uses metal extrusions, a polyimide-coated heated bed, and microcontrollers, but Jim’s giant’s controllers are modified for the machine’s size and his platform is heated by eight 1″x12″ flexible heaters connected to their own controller to ensure an even temperature along the entire build area.
Jim is also no stranger to the dangers of melting plastic at 200°, citing the Material Safety Data Sheet on ABS on his blog: “Thermal processing fumes may cause irritation to the eyes, skin and respiratory tract and in cases of severe overexposure, nausea and headache”. To deal with that, he’s got an enormous tube leading from the extruder to two exhaust fans that feed to the outside, where the, now infamous, UFPs can fly out into the atmosphere where I’m certain nothing bad will happen to anything at all.
Below is a video of it printing the largest print ever made on a homemade RepRap, a 3D lattice that almost fills the Giant’s entire build volume. After an impressive 48 hours of straight printing, the print head jammed, but the result is still a mighty 376 x 376 x 250mm or 14.80 x 14.80 x 9.84in. Jim calculates the total cost of the part like a true scientist, in terms of ABS plastic and electricity: “Based on the extruded volume, 238.7cc, this part cost me roughly $5 USD worth of ABS plastic. As for machine electricity costs, we can round up that the machine uses 0.5kWh, so running for around 48 hours will cost approximately $2.50 USD at $0.10/kWh. So a very rough estimate for the total cost of this print is $7.50 USD.”
And since demonstrating his skill as an engineer, Jim was offered a job at 3D Systems. He assures us, though, that the industry leader will not produce an army of giants with which to destroy Gotham. Instead, Jim just brings it along to Maker Faires and trade shows, a sort of sideshow act to attract passersby to the 3D Systems booth.
Hat tip to: Project Square.
Source: Grassroots Engineering