Lenny turned toward the small computer that was attached to the case. He tapped the keys for a moment, calling up a file in a CAD program, and it displayed a three-dimensional image of an intricately painted figurine of a clown. He used a trackball to rotate the image on the screen, then pointed at some parts on the upright supports of the printer.
“Another difference between this printer and others is that this one is also a 3-D scanner. You simply set an object on the print bed and tell it to scan through the computer, and it does the rest. Those lasers will get an absolutely accurate measurement of the shape and size of the object you’re scanning.” He pointed at the screen in front of them again. “Now, I scanned this figurine in a couple of months ago, as we were first testing the printer. Notice how it has almost a dozen different colors, counting the clown's face and costume, right? Now, watch this.” He tapped another key and the printer's nozzle began moving over the print bed at the bottom of the machine.
“That's going a lot faster than the ones I see on TV,” Noah said.
Jasmine, who was standing beside him, smiled. “It's called a Rep Rap, which means Replicating Rapid Prototyper. That clown is about nine inches tall, and a normal 3-D printer would take up to four hours or more to complete it. This one can do it in about eight minutes.”
Lenny grinned at them. “That's because of our formula,” he said. “Most 3-D printers use a solid string of plastic, melting it a little at a time to put it where it belongs. Ours is liquid, and the hot print head actually causes it to solidify where we want it.”
“Look,” Sarah said, “I can see its feet already. How do you make them so shiny? That almost looks like real ceramic.”
“Well, in a way, it is ceramic,” Lenny said. “Along with the color, we add a glazing agent that crystallizes quickly. As it's pushed through the hot nozzle, the glazing agent melts and gives it that shiny-wet look. Without special analytical equipment, you'd never be able to tell it isn't a real ceramic figurine.”
Suddenly, the print head rose away from the work it was doing, and a mechanical arm swung down from the top of the machine. A small cylindrical object, about an inch long and a quarter-inch in diameter, was placed inside one of the hollow legs that stood there. The arm then moved away, and the print head resumed its work, securing the little device in place.
“Before you ask, I'll just tell you what that was,” Lenny said. “That was the detonator. It has a small charge of its own, a super small battery and a microcircuit receiver that can be activated manually, or set to go off at a certain time or after X number of minutes. Give it a few more moments, it's almost done, and then we can show you what it's capable of.”
It took about four more minutes to complete the figurine, and then Lenny invited Noah to remove it from the printer. He picked it up and felt its weight, then ran his fingers over the surface.
“You're right,” he said. “If I hadn't watched you print it out, I'd never know this wasn't real. I'm assuming it's pretty stable? What would happen if I dropped it right now?”
Jasmine grinned. “Not a thing,” she said. “This stuff is so well bonded together that it wouldn't even break. Go ahead, try it if you want to.”
Sarah's eyes went wide, and she shook her head at Noah. “That's okay,” he said, “I'll take your word for it. What about impact, or fire? I know that C4 won't explode unless it's got a detonator, but it will burn.”
Lenny took the figurine from his hand and set it on a workbench, then picked up a propane torch and aimed the flame at its head. After several seconds, it was obvious that the flame was having no effect, so he turned it off and picked up what looked like an eight ball from a pool table.
“I made this the other day,” he said, “but I don't really need it.” He set it on the workbench and then picked up a small, heavy hammer. He grinned at Sarah and then brought the hammer down as hard as he could onto the ball. It shattered into several pieces, and they saw that it had been hollow. Inside was one of the small detonators, stuck to the inner wall of one of the pieces.
“You could shoot holes through it, and it wouldn't explode. It takes a special detonator that uses Triaminotrinitrobenzene and Diaminodinitroethene in combination to produce enough heat and shock to set it off, but boy, when it does! Come on, we'll show you.”