So, what do you think about 3D printing? It’s an amazing technology, and it’s only in its infancy. Imagine where 3D printing technology will be in 5 years...10 years...50 years!
But right now, you have the opportunity to have some real fun and maybe even design some useful items with a 3D printer. It’s not futuristic technology—it’s here today, and you’re ready to go.
If you’re like me, you may have been bitten by what they call the maker bug. It’s a deep desire to tinker, to make things, to fix things, and to try to express your creativity by adding new tools and skills. 3D printing is certainly a fun technology, but it’s actually quite useful; many companies use 3D printing to create prototypes of products that will eventually be sold in stores. Inventors use 3D printing to test out sizes and shapes of items, such as gears and cases. Teachers use 3D printing as a tool for introducing the power of CAD software that is the core of many technologies and jobs of the future.
But 3D printing isn’t the only technology that can satisfy that maker bug. Hobbyists and professionals around the world have access today to some amazingly powerful tools that weren’t readily available just 10 years ago. Costs have dropped, sizes have decreased, and tools that were previously available only to multimillion-dollar manufacturing corporations are now being found in garages, workshops, and schools everywhere.
I’m not talking about the standard shop tools, like table saws, drill presses, routers, and lathes. I’m talking about more powerful tools, and I introduce you to a few of them as I wrap up this book. You should have a good grasp of how a 3D printer works and the hardware and software used to make the magic happen. That knowledge is going to help you make another jump (if you want to do so) to some other tools that will be much easier to learn about now that you’re experienced with 3D printing.
The first tool I want to discuss is called a CNC machine. Before I show you what one looks like (and many different shapes and sizes exist, just like 3D printers), I’ll go over briefly what a CNC machine is and what it can do for you. I’m going to use what you know about 3D printers to compare and contrast with a CNC machine.
First, a 3D printer performs what is called an additive process. Additive—something is being added. Pretty straightforward. What’s being added is melted plastic, layer by layer, to create a solid object.
A CNC machine performs what is called a subtractive process. It takes something away. And that something depends on the material you are working with. A CNC machine uses a milling bit in lieu of the hot end found on a 3D printer. The milling bit looks like a drill bit, and it spins at a very high speed. If you can imagine a 3D printer with a spinning drill bit on the end instead of the hot end and leave the motors in place to control the movement of the spinning bit, you’ve got the basic idea of a CNC machine.
The milling bit removes material instead of adding material. Place a small piece of plywood on the worktable, and a CNC machine (using the familiar g-code) can be instructed to move the milling bit to and fro over the plywood. The Z axis controls how deep into the wood the milling bit cuts. Using a combination of movement along all three axes, you may be able to start picturing how a CNC machine can remove wood (in small amounts), leaving behind an object.
On the simple side, a CNC machine can be used to engrave your name, for example, into a variety of materials—plastic, wood, and metal being the most popular. (Note that you must select the proper milling bit for the material you want to work on.)
On the more advanced side, a milling bit can be used to create intricate designs and even cut out objects from a larger piece of material.
Take a look at Figure 11.1 and you’ll see one example of a CNC machine. This is the ShopBot Buddy from ShopBot, a manufacturer of CNC machines.
The first thing you’ll notice is that it’s larger than the Simple 3D printer. Most CNC machines are larger, but some desktop versions (often called milling machines) are just as tiny as the smaller 3D printers.
Most CNC machines work like 3D printers—a series of motors move the milling bit around on the workspace. Unlike the Simple, however, where it’s the print bed that moves left and right (instead of the hot end moving left and right), most CNC machines don’t move the workspace. Instead, the milling bit moves in all three directions. The milling bit shown in Figure 11.2 moves left and right, forward and backward, and up and down; the workspace stays put.
This is a 3-axis CNC machine. It moves along the X, Y, and Z axes. But there are more advanced CNC machines called 4-axis that also allow for rotation like a lathe. It’s a bit beyond the purposes of this discussion; just be aware that CNC machines have been around longer and are much more advanced, offering more features and tools than 3D printers do.
You’re already familiar with how to control a 3D printer with g-code. A CNC machine works the same way, but differences exist. When it comes to controlling a CNC machine with a computer, you’re also dealing with depth of cut. 3D printers build up in layers, but CNC machines cut down into material, so the software needed to do this is often more advanced than the Repetier software you learned about in Chapters 5, “First Print with the Simple,” and 7, “Creating a 3D Model with Tinkercad.”
There’s a lot more to know about using a CNC machine than I can provide here, but you’ll be happy to know that dozens of books and websites are dedicated to CNC technology. If you’re truly interested in expanding your skills, you shouldn’t find jumping from 3D printing to milling with a CNC machine too difficult. But just as with 3D printing, you’ve got to start simple with a CNC machine and continue learning and experimenting to improve your skills with this powerful tool.
You won’t find too many CNC machines in the price range of low-end 3D printers, and it’s not uncommon to spend $2,000 to $10,000 on a hobbyist-level CNC machine. Fortunately, there’s an entire hobbyist market out there dedicated to building homemade CNC machines. A good friend of mine, Patrick Hood Daniel, offers a variety of kits and plans if you’d like to try your hand at saving some serious cash. Point a web browser to http://buildyourcnc.com for more information.
Lasers. I love that word. It just sounds high-tech.
Imagine for a moment replacing the milling bit in a CNC machine or the hot end in a 3D printer with a powerful laser that can cut through wood, plastic, and other materials. Using a similar method of controlling the motors, you could focus that laser beam onto the workspace and let it cut out shapes and letter curves in whatever material you desire.
It may sound like science fiction, but it’s a reality and it’s called a laser cutter. Take a look at Figure 11.3 and you’ll see one of the more popular laser cutters from Epilog, called the Zing.
One of the first things you might notice about a laser cutter is how much it looks like a large box. There are a number of reasons for this. First, it is for safety—you don’t want someone putting their hands anywhere around a working laser. Second, a lot of materials produce fumes when cut by a high-temperature laser, and the enclosure helps to redirect those fumes using a special ventilation tool that sucks out the fumes and expels them elsewhere (usually outside). Finally, some materials (like glass) can reflect a laser, so the enclosure helps protect eyeballs from an accidental reflection of the beam.
Inside the enclosure you’ll find a setup similar to a CNC machine. The workspace stays put, and the laser moves left and right and forward and backward. The only difference is that a laser doesn’t need to move up and down—it either cuts all the way through a material, or the software controlling the beam uses a series of pulses that cut only a fixed depth into the material.
As you can imagine, laser cutters are not cheap. Between desktop versions of a CNC machine, a 3D printer, and a laser cutter, you’ll definitely spend the most on the laser cutter. It’s a technology that hasn’t dropped in price as fast as the other two technologies. But it is dropping. Ten years ago a laser cutter would have cost you well over $100,000, but today you can find hobbyist versions for under $10,000. There are even “build your own” versions, such as the one from buildyourcnc.com shown in Figure 11.4, that you can grab for less than $2,000.
Laser cutter special software is also needed to control laser cutters, so you’ll typically get this software when you purchase the cutter. You should also be aware that the laser tube that comes inside a laser cutter must eventually be replaced; it’s a consumable item, meaning that it has only so many hours of usage. Be certain to inquire not only about the laser tube’s expected life before making any purchase of a laser cutter but also about the replacement tube cost.
The last item I want to recommend is one I do not own. I have a CNC machine, a laser cutter, and a few 3D printers, but the plasma cutter remains one of those tools that I’m okay with renting when I need it rather than purchasing. Let me explain.
A handheld plasma cutter is your go-to tool for when you want to cut sheet metal. It’s a dangerous tool, and there’s definitely a learning curve that must be overcome with some training. But if you’re into cutting metal with extremely accurate cuts, this is the tool you want.
Now, take the handheld plasma cutter and think about mounting it in a machine that will let the cutter be directed along the X and Y axes, and you’ll have the basic idea of a computer-controlled plasma cutter. Software directs the movement of the plasma cutter, allowing for finer and much more accurate cutting of sheet metal.
In Figure 11.5, you’ll see one of the most popular computer-controlled plasma cutter frames on the market—the PlasmaCam. (Point a web browser to www.plasmacam.com and watch a video of the tool in action; it’ll blow you away.)
Why do I call it a plasma cutter frame? Because the PlasmaCam is simply a table/workspace and motors that are used to move a handheld plasma cutter that is mounted in the frame. You must purchase a plasma cutter to be mounted in the frame. (There are a variety of plasma cutter manufacturers, so you’re not locked into one particular brand.)
Computer-controlled plasma cutters like the PlasmaCam typically come with special software for cutting out two-dimensional objects in sheet metal. Again, if you understand how 3D printers work in terms of moving the working end (hot end) around the workspace, it’s not a big jump to understand how a plasma cutter could be directed to cut out objects from metal.
One final caveat: Plasma cutters produce a lot of sparks as they cut metal, and that’s one of the reasons why I don’t own one—the potential to start fires. Plasma cutters are ideally used in areas away from flammable materials, making them a bit more difficult for the home hobbyist to use safely. When I need some sheet metal cut, I’ve got a local machine shop that has a variety of tools, including a computer-controlled plasma cutter. I provide them with the file containing the shape I want to have cut out, and they provide the sheet metal and the tool and the final cutout. You may not ever own a plasma cutter, but you should know that there are shops that will rent you the time on one or do the work for you (at a cost, of course).
I hope you are beginning to get an idea of what someone with the right skills and tools could create. With a 3D printer, a plasma cutter, a laser cutter, and a CNC machine, you’d have quite a collection of advanced tools to make just about anything your mind could come up with.
But if you’ve got none of these, the 3D printer is definitely the place to start. You’ll learn some CAD, spend less money, and have access to a tool that’s a bit safer than the other three. If you find that you’re enjoying designing and creating things with your 3D printer, you can always expand your horizons and add a new tool (or two, or three) and open up even more opportunities to explore.
Have fun!