Before You Buy a CNC

We're very enthusiastic about CNC tools ... especially ShopBots. Our tools make things. They will help you produce more and produce better; they will earn and save money for you. But before you buy any CNC product, consider the important points discussed in these sections. We want you to be happy with your purchase and excited with CNC. One of the best ways to do this is for us to help you make sure that your expectations are realistic.            - Ted Hall, President, ShopBot Tools, Inc

1. Concept to Cutting File:  Understanding Cutting Files, also called ShopBot 'Part Files'

Learning how to use the ShopBot Control Software and to run the ShopBot is pretty easy. We've only set aside 5 hours for mastering it. But this is only a small part of using CNC. Although you can enter individual commands with the ShopBot Control Software to move the cutter, most of the time you will want the ShopBot Control Software to run cutting files. These files tell the cutter what path to follow to cut out or machine your parts. You will need to learn how to create these files.

There are many different ways to design and create cutting files for your ShopBot. For simple shapes and cutoffs, you can type command directions directly into the ShopBot Control Software. Or use the ShopBot Editor (or any text editor such as Notepad) to write and save the commands into a cutting file. You might even scan a 3D sample with our digitizing probe to make a Part File that is ready for cutting. Usually however, cutting files are made with design software, often called CAD/CAM software for Computer Aided Design and Computer Aided Machining. The ShopBot PartWorks design software that comes with your CNC router is one of the best and easiest to use CAD/CAM software programs available. Using PartWorks, or some other design software, will be where much of your effort is invested in learning how to effectively use your new CNC router. Mastering one method or another of going from concept to cutting file using design software is of primary importance in becoming productive with a CNC tool.

2. Production:  Mechanical Considerations Related to CNC Cutting and Machining

A CNC tool pushes a rapid-turning cutter through material with a great deal of force. You must think about cutters, speeds, direction-of-cutting, waste, and dust collection. These considerations are part of the new “craft” that you will be mastering. The most important new issue, though, will be how you are going to hold your material in place during cutting. There are many hold-down solutions and you will need to decide on what the best solutions are for your specific production situation. In general, material needs to be held firmly and flat. Even the slightest movement of the part during cutting will contribute to uneven cutting or poor edge quality. Your hold-down can be as simple as a screw or clamp. For repetitive production tasks, a fixture or jig that utilizes mechanical force or vacuum can be very effective. The most general-purpose solution is a universal vacuum that draws through a sacrificial bleeder board using a heavy-duty industrial vacuum pump/blower. ShopBot offers these general-purpose, vacuum hold-down systems, but they are expensive and are not optimal for every situation. If you have not had experience with CNC and vacuum systems, please give us a call to discuss your hold-down needs with our technical/sales people. It might also be a good idea to use your ShopBot for a while before committing to a specific hold-down approach. Experiment with holding down your parts in various ways and test different approaches in your production environment with your specific projects. A vacuum system can always be added later. [Also see Conventional vs Universal Vacuum Hold-down.]

3. Culture:  Two Recipes for Frustration (if not disaster ...)

Surprise CNC. Putting a new CNC tool into a production environment where the tool may be seen as a job threat, or too significant a learning challenge to master, is not likely to work well. The two mastery hurdles noted in 1 and 2 require that someone in your operation takes ownership of the new CNC, brings it online, and champions its use. As noted above, they are pretty amazing tools, but effectively incorporating them into your operations will not occur by magic. Reaping the benefits of their capability and productivity will require commitment and probably a production and cultural change.

Selling Before Buying. Buying a CNC tool to complete a contract that you've already accepted puts you under tremendous pressure. Not only must you install the tool and get familiar with using it, but you must also master the CAD/CAM software needed for the project and get the project fixtured and set up for efficient production. It's pretty easy to clamp an board down and cut a simple shape as soon as your new tool is running, but it's a lot more difficult to create an efficient and reliable production system for multiple parts or to machine an intricate or complex part. We recommend that you do not accept a contract for CNC work before you've gotten your CNC system up and running and understand how you're going to put it to work. This is a matter of appreciating that the tool represents a new culture that you need some time to master.

If you must take on a project before having your CNC system fully operational, consider purchasing our optional installation and training package. We also provide part-design and production set-up services that can help you get going. We have a technically skilled and creative team ready to work with you. Additional production services are not cheap, but may be a bargain for you in the long run if you must get something out the door in a hurry.

Yet, even though we can provide installation services, we recommend that you set up your own ShopBot and spend a little time getting familiar with its operation before you are not under the pressure of getting a job out. Our tools are very straightforward; you will get a thorough understanding by just doing the small amount of assembly required to position and set the tool up. Do some sample designing and cutting, and practice holding-down or fixturing parts. Then, accept that contract -- you are still going to pay for your new ShopBot in a few months.

If Price is Your Primary Consideration

If you are reading this note, you are already aware that ShopBot is committed to providing high quality, and very affordable robotic tools. But if cost is making it difficult for you to get going with a CNC tool, there are several things you can do to keep the initial dollar layout to a minimum. Your tool will be no less capable than a tool with more expensive options, but you may invest a little more of your time and effort in getting it fitted out. Here's what to consider:

• Purchase one of our entry-level PRSstandards. You can upgrade to a PRSalpha (our higher-performance, closed-loop CNC) later if you wish.

• Develop Your Own Hold-Down System. As mentioned above, a general-purpose, high-volume, vacuum hold-down system is expensive but it is not the only choice for holding down your material. If you need vacuum, consider a more affordable shop vacuum that can be used with templates for effectively securing your parts. Appropriately placed clamps or double-sided tape are other options. [Vacuum Systems] [Check out the ShopBot Wiki and the Forum for more vacuum and hold-down info.]

• Go with a Standard Router instead of a Spindle. A high-frequency spindle offers many advantages over a router (power, reduced run-out, less noise), but consider initially using a standard router to evaluate what you will actually need in your particular production situation. A spindle is more expensive and will probably require an additional electrical circuit and wiring. Go with a router to reduce your initial investment. [Router vs Spindle]

• Attend a ShopBot Training Session. We offer a monthly, two-day Training Class at our facility. Training covers use of your ShopBot and its Control Software as well as a thorough introduction to the PartWorks design software. We focus on getting from your idea to a Part File. Also, try to find a “Camp ShopBot” in your area [Camps]. These are user-organized, weekend sessions where ShopBotters share techniques and projects … a great place to learn new approaches to your work. Training and Camps can also clarify for you what you really need and what you don't need and you'll find lots of advice on how to save money.

• Pick Your Tool Up at ShopBot. Especially if you plan to attend a training session, you can save $200+ in shipping expenses if you pick your tool up while you are here. Please note that you must furnish us with a manufacturers certificate or you will be charged full NC state sales tax if you pick up the tool at ShopBot. With a manufacturers certificate, you pay $80. Give us a call if you have questions about this one.

If Convenience, Timing, and Efficiency Are Your Priorities

We can provide a complete package that includes tool installation and training, as well as part design and production set-up if you need it. We have a technically skilled and creative team ready to work with you. These additional services are not inexpensive, but may be a bargain for you in the long run if you are anxious to be productive quickly.

Even if we are going to train you, get involved with your design software early. Start using your design software before you get the tool and learn how it relates to the ShopBot Control system, which you will be able to run in Preview Mode even without a tool.  You will get maximum benefit from our training if you are already acquainted with the software.

Unpack your ShopBot before we get there. Have the set-up area ready and any new electrical service installed (and an electrician on call to hook up the Control Box if not already wired). Set up the computer you intend to use with your ShopBot. This will improve assembly efficiency and give us more time to spend with you on training.

Explore the resources and links available on this website to better understand your new CNC router and CNC production processes.