4 Most Common CNC Machining Problems

Just like most current technological devices, most CNC machine problems are caused by:

1.     User error

2.     Lack of maintenance

So, the majority of issues you run into are within your control. You can do quite a bit to avoid having these problems for the future.

Here’s what to look for:

1.    If Your Material Has Burns on the Outside Edge

This is a fairly easy problem to fix. Usually, you either have a blunt tool or too low of a feed speed. 

Verify if your feed speed is right for the material you’re cutting. Also, examine your tool. If you’re experiencing issues it may be as simple as replacing your dull tooling bit with a sharper one or increasing your feed speed.

2.    Making the Same Mistake Twice

CNC machining takes a lifetime to learn. At no point should you consider yourself a “master” who has it altogether. New situations happen that require new thinking and adaptation – even by experienced experts.

So, commit yourself to always learning. When you make a mistake, see what you can do to change so it can be prevented for the future.

3.    Chatter

When your CNC machine “chatters,” it simply means it vibrates during the cutting process. Chatter can happen to either your entire machine or just its tool. Chatter harms the quality of your work, dramatically reduces the life of your tool, and can even shorten the life of your CNC machine.

To prevent chatter from ever happening in the first place, simply make sure your cut width or depth keeps deflection below 1/1000^th of an inch. Most CNC machinists also react with slowing down. 

That’s not necessarily bad, but there is a better solution. Speeding up can also work, so simply test different RPMs first.

4.    Overheating, Which Can Cause Your Entire CNC Machine to Fail

Your CNC machine can reach more than 150 degrees Fahrenheit on the inside. Filters can get clogged with dirt and debris, which can even push temperatures even higher. Of course, this can cause serious damage to your CNC machine.

Prevention mostly consists of routine maintenance. Have a regular schedule for clearing dirt and dust from your AC units and filters. Cutting fluids and metal shavings should be cleared away routinely, as they can potentially contaminate your equipment.

Overheating rarely results from problems other than these. If perform routine maintenance, you shouldn’t have to worry about any serious issues. Be sure to keep these four tips in mind as you do your work. 

4 CNC Machining Myths and Misunderstandings

How long have you been a CNC machinist? Years? Decades? Are you considering or just getting started?

Every profession has its facts – and some questionable knowledge. Today, we’re going to take a look at some of the myths and misunderstandings out there.

Here’s some you may have heard:

1.    If You’ve Had Success Running a Job Before, You Won’t Have Any Problems In the Future

To get the same results, you have to set your CNC job up in exactly the same way – without any variation at all. If you’ve had a miscue of some kind, you’re likely misremembering how the job was done in the past.

2.    CNC Machining is Easy for Anyone to Do

There’s a little bit of truth to this, but it’s still an exaggeration. CNC machining is easier to start from scratch. It allows people with less experience and skills to produce more consistent results. You can automate much of the process, which takes away some chance for human error.

However, programming, setting up workspaces, monitoring production, and making adjustments to the cutting process takes experience. It definitely pays off with faster production times and higher product quality.

3.    Jobs Always Take the Same Amount of Time to Run

They do…if everything goes exactly as expected. However, while CNC machines automate work and make production easier, they don’t guarantee the same run time for each job.

For example, your cutting tools will wear down. You may have different operators who take varying amounts of time to keep the machine running at a good speed. With repeating jobs, you should be able to have a reasonably close time of completion. For new jobs, however, time to complete may vary.

4.    CNC Machines Don’t Use G-Code Anymore

Just about every CNC machine uses a CAM system - that’s right. However, G-code is the output of every CAM system, which your CNC machine uses to run. Even today, it’s faster for CNC machine operators to modify the G-code than it is to make changes in the CAM system.

Code still matters, a lot and so does the experience and skill of the CNC machine operator.

Yes, running a CNC machine is easier than conventional machinery, but it’s not technically “easy.” Just like any other profession, the more skill and experience you have, the better results you’ll get. 

How to Grow Your CNC Programming Skills

Some mistakenly believe learning CNC programming is “easy.” It’s easy to get started and nail the basics but just like anything else, you can spend a lifetime mastering different techniques and nuances involved.

Here are some tips for increasing your CNC programming skills:

1.    Getting Started

For beginners, you’ll pick up CNC programming more easily if you’re naturally good at math – especially coordinate geometry. You can find most of the G-codes you need online, and watch plenty of YouTube tutorials on how to work with them.

A simple program contains definition statements, machining statements, and closing statements.

2.    Do Some Practice Jobs

To really grow your skills, you must become a “sponge” as they say. Read machine manuals and ask as many questions as you can think of to the experienced operators. Pick the brains of the smartest, most talented employees at your company and give yourself every opportunity to practice.

Eventually, you’ll hit the limit of what you can learn at your job. Once you feel like you’ve done that, expand your questions to new shops. Every shop operates differently, so you’ll definitely learn some new things at each one.

3.    Find a Mentor in Your Workplace

Ideally, you want to learn the specific thought processes that go into teaching how to use a CNC machine and the location of all the tools to make the necessary modifications to your work piece. 

Working with someone who’s made all the mistakes themselves in the past saves you a lot of lost time and effort into knowing what works and what doesn’t.

Of course, you’ll still make mistakes of your own but, you’ll have someone you can trust to set you on the right path.  

4.    Online/Technological Options

There are also apps that help you learn CNC programming in your spare time. There are even free courses at sites like Udemy and Instructables. You can certainly learn both beginning and advanced 

CNC programming skills. You have a long list of options when it comes to learning since there are a number of private and independent operations that teach CNC programming too.

Lastly, what’s Your Why?

It’s important also to know why you want to learn CNC programming. Are you a hobbyist? Are you a professional looking to get ahead? Or, are you a supervisor who wants to learn how to better communicate with employees?

Depending on the level you’re trying to achieve, impacts how far you’d like to go and what methods to achieve that goal.

6 Advantages of CNC Machining Over Conventional Machining

Do you use conventional machines in your personal shop or business? They do have some benefits, but so do CNC machines.

If you’re considering adding a CNC machine to your production processes, here are some reasons you may or may not want to:

1.    You Don’t Need Extensive Experience or Skills

With conventional machines, they may require a long period of experience to operate and get the most out of. While experience is a great benefit for CNC machines, in some cases it may not be as necessary as conventional machines. Production quality may be easier to maintain since CNC machines take the human error factor out of production. While both machines take training, consider which machine will be able to maximize your production with a minimum amount of training.

2.    Products Can Be Easily Replicated Thousands of Times

Conventional machining works well when you need to make a single custom piece. If you have high production quotas where you need to produce the same part multiple times, CNC machining makes more sense. CNC machinery lets you program your machines to make the same cut over and over with a repeat in quality.

Conventional machinery needs help from an experienced operator to make similar pieces. And even then, there are still small variations among the parts.

3.    Less Labor is Required to Operate CNC Machinery

Investing in CNC machinery can drastically cut your labor costs. Conventional machinery requires extensive knowledge, experience, and skill, which can drive up your labor costs. With CNC machines, you can get the same high quality while hiring fewer workers and you’ll also continue to have high production levels.

4.    CNC Software Increases Your Production Options

More advanced software can help you manufacture products which are difficult or nearly impossible to make by hand or on conventional machinery. You can also update the software as necessary to improve your CNC machine’s functionality.

With conventional machinery, there is little to no software which doesn’t allow you to have a repeatable cut quality.

5.    No Prototypes are Necessary with CNC Machines

CNC software lets you simulate your idea before even cutting it out. You don’t have to actually produce a prototype, which costs time and money. The time spent creating revision can be drastically reduced through the utilization of the software. You could potentially save weeks or even months of production time so you may spend your labor elsewhere.

6.    CNC Machines Fit the Skills of Modern Workers

Many of the mathematical and analytical skills necessary to successfully operate conventional machines aren’t as emphasized in schools as they used to be. As a result, in one sense, there’s a less skilled workforce available. While you can’t go wrong with hands-on training, the industry is heading towards the digital age where tech savvy operators may be the ones running the machines.

Depending on the business or industry the modern workforce may have to learn how to operate both types of machinery. While one machine may be a better fit for you, keep in mind where your production may lead to in the future and how you’d like to get there.

Should You Buy New Or Used CNC Machinery?

Ultimately, only you can decide whether new or used CNC machinery makes sense for your business. 

However, this list outlines some of the top factors to consider when making your decision.

Here are a few things to think about:

What do you want to do with your CNC machine?

The main difference between old and new CNC machinery is the customization options and controller performance. Old CNC machines would quite possibly need extensive software and a controller updates in order to comparably perform to newer machines. However, if the old machine you’re looking at does exactly what you need and is up-to-spec in every other way, the price difference may justify the purchase.

How urgently do you need your CNC machinery?

If you need machinery in a pinch, it may make more sense to buy a new machine. It’s easy to find newer machines, and they typically don’t take as much effort to set up. But to find the right used CNC machinery for the job, at a good price, and in relatively good condition, usually takes extensive research.

What’s your employees’ skill level?

Generally speaking, newer CNC machinery has more sophisticated software that is user friendly and is capable of producing a consistent cut quality. Older CNC machinery may require more training since the software may not be as robust. Much of this depends on the specific CNC machine you’re considering or looking to purchase.

Will you link the CNC machine to an existing network in your shop?

Older CNC machinery is more difficult to network into your shop’s workflow since there may be compatibility issues. If the machine you need to purchase will operate stand-alone, then you don’t have to worry. Although, depending on what the machine might do it may be best to consider a machine that can quickly and easily join your shop’s network.   

What’s your budget?

With used machines, you want to look for later models with lower hours of usage. Generally, you’ll look at spending approximately $70,000 - $90,000 for a decent used model. You can, of course, pay much less than that but as the price lowers, so does the quality of the machine.

New machines go for approximately $100,000 - $300,000.

Do you have time to figure your CNC machine out on your own?

Before you invest in a used machine, consider the support that may come along with it. Is there a learning curve and will you have a difficult time getting support? You’ll have to do much of the setup, upgrading, and training on your used machines unless it is backed by the company you purchased from or the manufacturer.

Do you have the time for that?

Compared to used machinery, new machinery comes with great support and service readily available. More than likely, you’ll get up and running faster and more efficiently.

What Makes Sense for You?

There is no set right or wrong way when purchasing new or used equipment. What may work for one shop may not work for another. Be sure to take a step back and analyze what works best for your business in order to get the most bang for your buck!

4 Tips for Starting and Growing Your Own CNC Business

Where’s your CNC shop in its life cycle? Are you a rookie or a seasoned veteran? Do you have one machine or multiple machines that constantly manufacture? Are you a bustling factory with a long list of customers you need to keep happy?

Regardless of where you’re manufacturing capabilities are at, you can benefit from the tips below:

First, focus on mastering one thing

This holds true especially for new CNC machine shops. As your business grows, you can diversify but first, you must master one method or production. Once you’ve began to produce consistent and quality results, customers come easier and stay with you longer.

Consistency and stability is the key to remaining in business. First, achieve a perfect balance before you start looking into other things to attract a whole new market or production.

Build a strong network of contacts

Make sure you have a method for reaching out to new and additional contacts so you can grow your network. One great customer experience can lead to another and it can possibly gain even larger traction by a word-of-mouth reference. Be sure to complete time-sensitive jobs on time and provide a quick turn-around to give your customers and contacts a reason to come back to you for work.

Consider customizing your own components

By providing customers with custom components, it diversifies your business from the rest. Be capable of creating something no one else can in order to promote customers to regularly come-back and attract new designs.

It could even be something as simple as special bicycle components. If you have a specialty piece you can produce and sell, that’s a big plus for the grow of your business.

Expand as your revenue allows

Make sure you have the demand in place, before considering expansion. As demand grows for your services and products, then you can acquire more machinery and potentially more staff. Remember, only purchase new machinery when it’s cost-efficient.

Once you’ve got these tips down, create a plan for the future of your production capabilities. 

Consider diversification along the way. That protects your business, just in case one arm of it suddenly loses demand.

If you keep these points in mind as your grow your CNC manufacturing, it will help set a path to success and grow for the future.

How to Create the Right Warm-Up Routine for Your CNC Machine

Think of your favorite athlete. While you rarely see them warming up on TV, every professional athlete has a warm-up routine they use. If they don’t, they risk injury, and they often don’t perform as well during the contest.

Though not human, your CNC machine works the same way and needs a warm-up routine of its own too.

When you have the right warm-up routine in place, your CNC machine’s lubricated better, which reduces friction and wear and the potential for something to break, and improves the life of your CNC machine. That saves you downtime and unnecessary repair costs.

As you know, heat causes thermal expansion in your CNC machinery. When you warm up your machine, that keeps its temperature stable, which minimizes thermal expansion. That means you get consistent cutting. When you don’t warm-up your machine, thermal expansion has a more pronounced effect, which leads to inconsistent machining. That means you could end up with some unhappy customers who don’t like their product.

When Should You Warm-Up Your CNC Machine?

There’s four times when you know you need to run your warm-up routine:

• Any time your CNC machine has been idle for more than 4 hours.
• If your shop is colder, you should run your warm-up routine even if your CNC machine simply sits idle during your lunch break.
• If you must have a tight cut every time, let the warm-up routine run whenever you take small breaks of any kind.
• When you need to run your spindle at high speeds right away.

What Should Your Warm-Up Program Do?

In many cases, CNC machine manufacturers supply their own warm-up program. If they give you one, then your job is done. No need to create a different warm-up.

However, that’s not always the case. So, you have to create your own warm-up program. Here’s some things to consider if you find yourself in that situation:

• Run your warm-up routine for 200 seconds, starting with the slowest RPM and working your way up to the maximum.
• If you’re running a high-speed machine, again start slow, but only work your way up to the normal operating range, rather than the maximum operating speed.
• You only need to do this for your initial warm-up in the morning. If you have a break during the day, leave your spindle running at its normal operating speed during that time to keep your CNC machine ready to go.
• You should also cycle your tool changer, lathe turret, and briefly turn on the coolant to make sure all are ready to go.

With a simple warm-up routine like this, your CNC machine stays ready to make precise cuts. You prolong the life of your machine and minimize the need for repairs. And your customers stay happy because you give them quality product every time.

Keep this routine in mind whenever you need to run your CNC machine.