Safety First: How to Work Smart in Your First CNC Machine Shop
Remember learning to drive a car for the first time? Absolutely everything was new and overwhelming, now you barely even think about it. This is the exact same journey you’ll go through when working at your first CNC machine. There’s the whir of machines, chips flying; it’s all really new and exciting – and incredibly dangerous if you aren’t prepared. Here’s some guidelines to start your career off on the right foot as a safe and smart CNC machinist. Of course, you should always follow your own shop’s protocols as well.
Machines Are Not Smart
Machines are not smart, they’re dumb. That $250k DMG Mori might have the most advanced multi-axis system around, but at the end of the day it relies on a human to operate it, and stop it. That means you, and only you, are the first and last line of defense should anything go wrong. If your arm or hair gets caught in a spindle, that machine won’t suddenly stop. It’s going to keep doing what it does, machining away.
Why bring up such an obvious point? Because it’s really easy to go into autopilot mode on a machine shop floor. After a few years you’ll likely have your groove down and know how everything works like the back of your hand. But the minute you let your guard down is the minute that something can go wrong.
In a car, you can get in an accident and walk out of the mess without a scratch. There’s that extra layer of protection between you and the roughness of the road. But on something like a motorcycle, or a high performance milling machine, that buffer of protection is so much smaller. CNC machines might be safer with all of their enclosed parts, but you still need your awareness fully and completely in the present moment.
So how can you maintain your awareness? By working with a Safety First mentality. Now hold on, we’re not here to rattle off a list of shoulds and should nots. That’s for your company’s safety coordinator to do. If they require you to stick safety glass on every single moving part on your machines, then know they have your best interests at heart. Instead of hard and fast rules, we’re going to focus on practical recommendations and questions that you can use as a guide.
Know Your Environment
A high performance CNC machine or engine lathe is going to require your complete and uninterrupted attention. So is the immediate environment that your machine is located in. You’ll be working with new people, tools, and machines at all hours of the day. Here are a few questions to ask yourself as you move through your work shift:
Where are your hands?
Know what your hands are doing at all times. It’s easy to slip into a thought and suddenly lose track of your physical process. Are you tightening a bolt? What happens if the wrench slips? Are you going to slam your arm into a pile of sharp chips, a tool, or even just the sharp corner of a workbench?
Where are your feet?
One of the most common accidents on a machine shop floor is slipping. Do you have a strong center of gravity as you lift that heavy load? Are your feet away from any moving parts that could catch them?
Where are your manners?
Everyone working on a machine shop floor is likely (hopefully) in a deep state of concentration as they machine their parts. We always recommend not interrupting a coworker when they’re working on a machine, even the slightest distraction can lead to a costly mistake. And before grabbing a coworker’s tool, ask if you can borrow it. If your request is declined, don’t take it personally, we all have different relationships to our tools.
Know Your Gear
The gear you wear is your first and only line of defense if something goes wrong on the shop floor. Did some sharp steel chips just go flying across the room? Safety glasses will save your eyes. Or maybe you have some nasty coolant you need to handle that leaves some intense skin irritation. Latex gloves suddenly become your new best friend. This is the gear, or personal protection equipment, that we always recommend wearing, whether your boss requires it or not and whether it’s your 10th day or 10th year in the shop:
We always recommend rocking safety glasses that have side shields to keep any flying debris clear of your eyes. Remember, CNC machines slice through metal like it’s butter, but those chips come off sharp. Even on manual machines, coolant and chips can fly and the last place you want them is in your eyes. Safety glasses also come in really handy if you work with hand cutting tools which can suddenly break or shatter if used incorrectly.
Do your ears a favor and consider keeping a pair of ear muffs on as your machine runs full steam head. If the muffs are too bulky then opt for ear plugs. Or maybe double up and use both for extra protection.
Sharp chips tend to end up on the floor, no matter how careful you are, so close toed shoes are a must to keep your toes free of cuts and deeper lacerations. We always recommend sporting a pair of solid leather shoes. If you will be carrying around heavy objects then steel toed shoes are even better, as they’ll protect your toes from being crushed in the case of an accidental drop.
If you’re working on a grinder that doesn’t have a vacuum, then we absolutely recommend wearing a respirator to keep abrasive dust out of your lungs. Metals like zinc will reach temperatures above their boiling point when ground, which releases toxic fumes. Even operating some CNC machines like waterjets will create small metal particles that don’t belong in your lungs. Inhaling these can lead to serious health issues.
This is one of the trickiest pieces of equipment to recommend. Gloves and their usefulness is very much situation specific. For example, let’s say you grab a plate of steel with some leather gloves on. In this situation they did their job of keeping your hands safe from any sharp edges. But what if you wore the same pair of leather gloves while running a machine and they get caught on the spindle? Not good. On the other hand, latex gloves can keep your hands free of coolant with no risk of catching on the tool and sucking you in. Analyze each situation that you find yourself in and ask, will these gloves do more harm or good?
Leave the Bling Behind
Yeah, you like to look good, but that Haas machine already looks sharp enough. Remember that every item on your body, from jewelry to your hair needs to be kept away from any moving parts. Keep these recommendations in mind before heading off to work:
- Hair. If you have long hair make sure it gets tied back before stepping foot in your shop. Having your hair caught in a machine spindle can lead to serious injury or worse.
- Clothing. Avoid wearing long sleeve or loose shirts as the sleeves and excess fabric can easily get caught in a machine. Sturdy long pants like jeans or work pants are also good to keep chips and chemicals off your legs and out of your shoes.
- Jewelry. Leave it all at home. Anything that dangles or shines, whether that’s rings, earrings, necklaces, or eve watches. Those are all just waiting to get caught on a moving part.
Don’t Destroy Your Back
I know too many machinists that have met an early and pain-ridden retirement because they didn’t take care of their back. Yes, it’s a pain to remember how to lift properly especially if you’ve been doing it differently your entire life. Find a way to make it a game, get a buddy involved so you can literally watch each other’s backs until it becomes a habit. We recommend these lifting guidelines:
- Always keeping your back as straight as possible.
- When lifting a load, squat down and bend your knees instead of using your back.
- Tighten your core and use those leg muscles to lift, not your spine!
When working at your CNC machine, also try to be aware of the posture you hold throughout the day. Is your body aligned with your tools and workspace in a way that keeps your back feeling healthy and strong at the end of a work shift? Or are you walking out of the shop with a constant ache? Consider making some adjustments if needed.
Get Familiar With Your Machine
We’ve covered all the basics for keeping you as a person safe. Now it’s time to focus on a few tips for working with your machine. The recommendations below will apply to any CNC machine you encounter:
Use a lockout/tagout system
A lockout/tagout system is the process of powering down a defunct machine and locking the power switch with a lock. This will keep others from trying to use a problematic machine. In a standard setup only the service technician will have a key for it. Walking away from your machine without powering it down and securing it is just inviting trouble.
Watch closely for any inconsistencies
One of the most common causes of accidents is setting a tool or fixture offset incorrectly on a CNC machine. After starting your program, pay careful attention to how your spindle moves. This is especially important after doing a tool change.
You can run your program in single-block mode and view the “Distance to Go” to work through the code one line at a time to identify any issues before reaching cutting depth, making sure the tool length and part position are as expected.
Keep your workspace tidy
The workspace around your machine is just as important as the machine itself. At the end of a long day you’ll likely have a nice pile of debris that someone can easily slip on. Instead of waiting until the end of your shift, we recommend tidying up your workspace as you go. That’ll keep your boss – and your safety coordinator – happy, and keep you safe.
Work Safe, Work Smart
If this your first job at a CNC machine shop, don’t be overwhelmed. It’s going to be exciting! Remember, it’s just like learning how to drive a car for the first time. There will be a ton of new variables for your mind to juggle. New tools, new machines, new processes. Just take it slow and start those smart and safe habits right away. Remember, there’s never a “good” time to take your eyes off the road, or your CNC machine. It’s all hands on deck from here on out, enjoy the beginning of your new machining career!
Is your shop using Fusion 360 to automate their CNC machines? It might be a good idea to learn the ins and outs before your first day. Try Fusion 360 for free now!