CNC Router Introduction
Professional craftsmen can create high-quality products using hand tools such as circular saws, hand routers, and planers. However, manual production is too labor-intensive and prone to errors for many modern business applications. Computer Numerically Controlled (CNC) routers can automatically drill, carve, rout, and cut materials with incredible accuracy and speed to increase productivity without sacrificing quality.
While old CNC routers operated using punch tape, modern CNC routers use computers to tell the control system and motors how far to move and what to cut. A CNC router can turn raw industrial material such as wood or aluminum into finished products based on detailed designs you create using accompanying software.
CNC routers play a significant role in markets such as furniture design, circuit board manufacturing, plastic and foam fabrication, and education. They can allow you to complete projects in a few hours that used to take several days. This BuyerZone CNC Router Buyer's Guide takes you through the basic features of a CNC router, what it can do, the advantages of owning one, how to choose a vendor, and the various costs involved.
Why CNC routers?
CNC routers can work with sheets of wood, plastic, rubber, acrylics, or non-ferrous metals like aluminum. Your design possibilities are endless - you can cut slabs of wood for a chair or cabinet, make three-dimensional architectural moldings for furniture, or create custom-made guitars.
The main benefit of CNC routers is automation. You feed in a sheet of material and the router precisely cuts the material based on the design you created. Unlike manual machinery, you don't have to supervise each and every step. You simply set up the function you want your router to perform, walk away, and it will complete the job with accuracy up to ten-thousandths of a percent - results you couldn't get with a hand router.
You'll also save money on labor since you no longer need multiple people to work on a project. CNC routers are almost like "robot employees" - they works non-stop and can produce quality products every time. You'll still need employees to tell the router what to do, and it takes a skilled worker to run the machine. Because those employees need to learn how to run the complex machine and create designs using the software, you will have to pay them more than non-skilled workers.
CNC routers are also pivotal players in the prototyping industry. CNC prototyping is a very popular method for companies to create a "test version" of a product before going into full-scale production. It helps you pinpoint any errors in the production process before creating final versions. It also cuts down on the time and money needed to create a prototype by hand.
Basic Types of CNC Routers
The CNC router you select will need to handle your workload and be an appropriate fit for your work environment. Two basic considerations are how many axes you need on your router, and what type of motors it will use.
How many axes do you need?
In general, there are four levels of CNC woodworking machines you can purchase depending on the number of axes needed to do the work you have in mind.
- 2-axis: These are low-end routers for hobbyists to create basic signs or household items. They don't have a true Z axis, and they're not intended for industrial use.
- 3-axis: The most common CNC routers, the standard 3-axis router features an eight-foot long X axis, a four-foot Y axis, and a six-inch Z axis.
- 4-axis: The addition of a fourth axis allows material to be rotated around the vertical axis or on a CNC lathe for architectural millwork or advanced artistic carvings.
- 5-axis: Offers two additional axes for rotating parts and cutting three-dimensional objects without having to reposition them. Can machine five sides of a cube at once.
The vast majority of small-to-medium businesses choose 3- or 4-axis models. Hobbyists can get by with small 2-axis routers, and 5-axis routers are primarily used for the boating, automobile, and aerospace industries.
Stepper motors vs. servo motors
You have two options for the motors that will power your router: stepper or servo.
1. Stepper motors
A stepper motor moves in steps and keeps count of the steps to determine its position. This is an open loop control, meaning that after controller tells the motor to move a certain number of steps, it assumes that it's done. You don't get feedback letting you know where the motor is, and in complex designs, this can lead to errors.
Stepper motors have been around for a long time and are extremely reliable. They also require very little maintenance. However, they aren't as accurate as servo motors. They are also quite noisy and there are limited sizes available.
Their performance also depends on speed. Stepper motors have high torque (the force that causes rotation) at low speeds, but may suffer from choppy performance. High speeds are smoother but don't have as much torque.
2. Servo motors
Instead of counting steps, brushless servo motors send feedback to the computer to keep track of their position. This is a closed loop control: feedback from an encoder lets the motor automatically correct its location. By self-correcting, you get faster point-to-point speeds and increased power.
Servo motors are very accurate and smooth and the result is fine resolution of the finished product. However, they can be more expensive and are traditionally found only in high-end CNC woodworking machines. They require more maintenance in dusty environments, as the encoder is susceptible to dirt and vibration problems.
To maintain a servo motor's accuracy, you must tune it so it responds the way you want. Tuning is not an easy process and requires a lot of knowledge about the technology, but you gain greater control over the motor's behavior.
CNC Router Features
The motors are connected to one of three different drive systems to drive the machine's axes:
- Ball screw: Large screw drives with ball bearings that run around the gantry.
- Lead screw: Similar to a ball screw drive but without ball bearings.
- Rack and pinion: Straight gear drives.
The drive system will affect the cut quality and accuracy. For detailed cuts that need to fit together perfectly or for fine engraving, ball screw drives are the best. They can cut perfectly round circles without leaving flat sections on curves. However, they are more expensive. Lead screw and rack and pinion drives are much less expensive, but may provide a lower cut quality because of backlash when the motor changes direction. Usually due to loose or poor mechanisms, backlash will negatively impact the quality of your cuts: circles may be imperfect or inlays may not fit.
A thru-vacuum system uses suction to hold down the material you're machining so you don't have to hold it in place by hand. It also leaves your hands free to feed the next sheet of material into the machine.
CNC routers can have either manual single-cutter spindles or automatic tool changing capabilities. This means you can either perform a cut, stop the process, and change the bit by hand, or use a spindle that actually picks up a bit, makes a cut, and switches to a new bit.
CNC router bits are sold in groups with different sized cutters to handle various materials. They must be kept sharp at all times to ensure accuracy.
You typically get a set of basic CNC router bits when you buy a router, but you'll probably want to augment those by buying your own bits out of a catalogue or through a web site. Standard router bits with carbide tipping are relatively inexpensive ($20-$40 per bit) but they quickly become dull with use.
You may want diamond-tipped or diamond-abrasive bits, instead - they're much more expensive, but they last longer and will rarely need to be replaced. They can also be serviced four to eight times before they need to be replaced.
Selecting a CNC Router
Work with your vendor to decide which CNC router is most appropriate for your applications. In general, you want to avoid buying more or less than you need. Purchasing unnecessary bells and whistles is just a waste of money, and buying a machine that's less than you need reduces your overall return on investment.
Overall dependability is important, too. The router you purchase should be reliable and durable so it handles all of your carving and cutting needs with minimal problems, as well as easy to maintain so it keeps running smoothly.
Do test runs on your materials
Not all material is created equal - heavy wood like oak is more difficult to cut than plywood or plastic, and will require a stronger machine.
If the material you are cutting is very thick, some routers may not be able to cut it in one pass, and will need to make multiple passes to get the job done. Do some test cuts before deciding: you should experience only minimal vibrations and your cuts should be smooth and accurate.
Software and training
Also make sure you are comfortable with the software for your router: it should be fairly easy to program and to fix errors. The best way to become accustomed with the software is to take advantage of the training that most vendors offer.
Depending on your computer and design knowledge, training may only take a couple of days. It may cost $500 to $1,000 per day, but to get the most out of this significant investment, it's important to learn all you can about the software.
Price vs. total cost
Cost is obviously a huge factor in your decision and it's only natural that you want the best deal. Just make sure the price isn't the only thing you're concerned with. You need to consider your total cost of ownership.
A less expensive model might save you money initially, but if it doesn't provide enough speed or capacity for your future needs, you may need an expensive upgrade down the line. You also need to consider what short-term and long-term benefits the unit can provide, such as reducing your operating expenses and labor costs.
Size and weight matter, too
CNC routers are often heavy, space-consuming machines. If you are working with extremely large pieces of material, you may need an even larger machine than is typical. Make sure you have the physical space for the models you're evaluating, and that your floors can support the significant weight of the machine.
Choosing a CNC Router Seller
You have two options when shopping for a CNC router: purchase directly from a manufacturer, or go through their exclusive regional brokers.
- Manufacturer - Selling direct lets manufacturers keep costs slightly lower than distributors who have to include a markup. However, depending on their location, you may have to pay more in delivery and/or transportation costs for support staff. A manufacturer that has regional support centers near you can provide local support and maintenance options.
- Exclusive distributor - Distributors are exclusively licensed to sell a manufacturer's routers in their area. The main advantage of choosing a distributor is that by working with one in your area, you can be sure you'll get local support after the sale. Distributors may not have the same in-depth knowledge of the hardware and software that the manufacturer would, however.
Selecting a seller
Regardless of whether you buy from a distributor or a manufacturer, it's essential to choose a seller who is both knowledgeable and reliable. Find out how long they have been in business. If they have been around since the days of routers operating on punch tape, you can be confident they understand the business and have adapted with technology changes. Newer sellers may try to get you in the door with a lower price, but they may not have the experience or the references to win your confidence.
It's important to visit multiple sellers' offices - at least three to five -and have them demonstrate their CNC routers for you. Request that each of them machine one of your parts, and evaluate both the process and the results. If a seller doesn't have offices near you, they may be able to introduce you to one of their existing customers who is nearby and can show you how the machine works at their facilities.
A reliable seller will provide comprehensive training. You want a seller that can easily explain how the machine works and demonstrate how to use the hardware and software. It's preferable to have training at your offices so you can do the work on your machine with your operators.
Find out what the seller will do for you when something goes wrong. When the machinery is an integral part of your business, you can't afford for it to be down for long periods of time. Ask them how quickly they can have parts available, whether they provide direct support or employ the services of a third party, and if they can repair PC controller issues remotely.
If possible, try to find a seller that is a reasonable distance from your offices. You'll still be responsible for transportation costs, but it's far more economical to do business locally.
When you receive proposals from the sellers, make sure they clearly define everything you get. Read the fine print- what applications you get, an itemized list of costs, and warranty details. Also keep an eye out for "bait and switch" tactics. An unscrupulous seller could try to pawn off outdated equipment as "like new" without your knowledge. At this point in the deal, there should be no surprises.
CNC Router Pricing
You may develop a case of sticker shock when you start shopping for a CNC router - expect to pay tens of thousands of dollars for a quality, reliable machine. The benefits of owning a CNC router will justify the cost over time, but the initial investment can still be a hurdle.
HardwarePricing in the CNC router industry is tiered according to how much the router can do.
- Low-end ($5,000-$25,000) -- A basic 3-axis CNC router with a 4' x 8' base and 6-inch Z-axis can start around $5,000.
- Mid-range ($25,000-$50,000) -- Mid-range CNC routers are heavier machines used in the signage industry and other lightweight panel processing applications.
- High-end ($50,000-$100,000) - CNC routers at the high end of the pricing spectrum are suited for a wide variety of applications. They typically include steel frames and other features to improve performance.
- Highest ($150,000 and up) -- The highest prices are for the largest, fastest 4-axis and 5-axis routers. These top-end machines are customized for large plants with heavy-duty machinery needs. A fully loaded router with a vacuum table, pump, attached computer terminal, automatic tool changer, and additional accessories can cost upwards of $200,000.
Some sellers offer CNC router deals that include installation, software training, and shipping charges for $60,000 - $80,000. But in most cases, everything is sold separately to allow you to customize your CNC router the way you see fit.
A CAD software package to create designs for your router costs an additional $2,500 - $10,000. Most CNC router sellers sell this software, but don't feel compelled to buy it from the your hardware seller. Most CAD software is compatible with common CNC routers, so find the software that suits you best, even if you have to buy it somewhere else. You may have to pay an annual software maintenance fee of around $1,000 for support and upgrades.
You can upgrade your 3-axis router to a 4-axis router for $10,000 - $20,000. You can even upgrade a 3-axis router to a 5-axis router, but that can be an additional $100,000 - $150,000. It's more cost effective and less of a hassle to purchase a 5-axis router initially.
Shipping and transport
Shipping a heavy CNC router carries a considerable cost. With router weighing anywhere from a few hundred pounds to several tons, freight costs can range from $350 - $3,000 or more, depending on your location.
You may also incur additional costs just to get the machine inside once it is delivered. If your office is on the ground floor, it may be a fairly straightforward move, but if the router needs to go on an upper floor, you may need to hire riggers to hoist it up and in. For the largest routers, the process may even involve cutting holes in the walls or removing windows, so be sure you plan out the delivery process before the router arrives.
Installation and training
CNC sellers typically charge about $500 - $1,000 per day for installation costs. It can take anywhere from a half day to a full week to install and test the router. While you can assemble and install a low-end router yourself, for most industrial models you're better off leaving installation and set up to the seller.
Vendors will provide training on how to use the hardware and software, usually at your facilities. Training typically costs $500 - $1,000 per day for two to three.
CNC router sellers offer extended service warranties for 5% - 10% of the list price for each year covered. Most warranties include parts and on-site labor, but trip fees and other labor costs may still apply. Make sure to ask your seller exactly what is covered so you're not stuck holding the bill for repair charges.
Many manufacturers offer used CNC routers for 25% to 30% off the new price. They purchase routers from auctions, factory closeout sales, bankrupt companies, and businesses that no longer use their current equipment. Then they clean up the machines, replace any worn or broken parts, upgrade the controllers, and resell the refurbished routers.
For businesses seeking an inexpensive entry point to the technology, a used CNC router can be a good choice. However, if the router will get heavy usage, play a critical role in your production cycle, or need the latest technology, it makes sense to buy a new machine. The benefit to newer CNC routers is increased reliability and new technology. Manufacturers selling used equipment add new technology to pre-owned routers, but those costs will add up.
The warranty is critical when buying a used CNC router: refurbished machines should always include a one-year warranty - you simply can't take the chance that something will break. You could spend even less money on an "as is" unit, but the quality is generally low and you will get little to no support.
If you do buy a used CNC router, make sure the seller walks you through all of the upgrades and replacements made to the unit. Also make sure they will provide support for the system beyond the one-year warranty: manufacturers may not provide replacement parts such as control systems for on older models.
CNC Router Tips
Leasing options. Because CNC routers are so expensive, leasing is an attractive alternative for businesses that don't have significant capital on hand. Secondary sources such as banks and machinery leasing specialists can furnish you with "lease to own" agreements - once the terms of the lease are complete, you can purchase the CNC router for a nominal fee. This is advantageous since the depreciation of a CNC router is very slow, so even if you decide to pay it off in five, 10, or 15 years, you will have paid into a machine that didn't lose much value.
Router bits vs. drill bits. Even though router bits are similar to the drill bits, they're not exactly the same. Many CNC router users destroy their router bits and achieve poor performance by programming the router to drive the bit straight through the material. Certain bits with plunge tips are designed to bore straight through the material, but most should be programmed to go in at an angle.
Take a walk. Many routers offer remote access so you can log in from another workstation and control the motions of your CNC router. Once you master how to program the software, you can create a job, set the material, and let the machine do the job on its own.
Power save. A CNC router actually uses more power if you turn it on and shut it off repeatedly than if you just leave it on throughout the day. It takes a lot of power to get a machine this size started and you can wear out the motors by turning it on and off too frequently.
Trade shows. Whether you own a large business or you're simply a hobbyist, check out a few CNC router trade shows. You can observe and even try out a variety of different machines from different dealers before you meet with a single one.
Keep it clean. Expensive repairs can be easily avoided if you maintain the machine properly. If the vendor has to come out to fix something you could have taken care of yourself - such as removing wood chips from the grooves of the router - it's going to cost you unnecessarily.