Tag Archives: machine shop

What Is Lean Manufacturing?

Any company in the machining industry has to incorporate Lean Manufacturing in their business and process plan to survive these days. To put it in simple terms, lean manufacturing is the production practice of being efficient by eliminating any ‘waste’ in the process plan. Though they may not call it this, all companies strive to be lean because it makes their customers happy, and ultimately, more money.

Although there was seven original “Wastes” involved in lean manufacturing, we’ll look at eight of the most common ones in a machine shop. Most of them are simple, but it can take a lot of work and orchestrating to implement them all. There is no perfect company that has it all figured out. There is always room for improvement, which is why employers seek new ways to lean out their manufacturing process. The acronym for this practice is “DOWNTIME”. Now you could just look this term up on wikipedia, but it won’t give you a real perspective or example of what it means. Those are just general illustrations in the manufacturing industry, but working in a machine shop may produce different scenarios.

Defective Production:

If bad parts are made, it takes more time to either re-work it or make another one. More material, more machine time, more tooling wear, which can add up to almost double the cost of a part. The machine shop pays for this and not the customer, and that is why it is on the list of big “wastes” that companies try to eliminate. We are only human, so mistakes do happen occasionally, but the goal is to decrease the percent of defective parts.

Overproduction:

I believe that this one can go either way, but if space is expensive, then overproduction is definitely considered a waste. If you make extra parts for a customer, it costs more time to make them, and the excess supply of parts costs more to store because it takes up more space in between machining and shipping, plus the time it will take for the customer to order more. If something happens to the customer and they discontinued that part or went to a different vendor, your extra inventory has now turned into a complete waste of money.

Waiting:

There’s two ways you can look at this; the parts that are waiting, or the machinist that is waiting. This happens whenever you have stock waiting to be cut or for operations on a machine. There is usually a waiting time in between finishing the parts and shipping. This takes up valuable time, as well as space. Although it may not seem like a big difference if parts are waiting an extra day or two to be worked on or shipped, the quicker you get the parts out your door, the quicker you can move on to another part/order.

Non-used Employee Talent:What Is Lean Manufacturing

This should be an easy, but too many employers miss it. If you have an employee that is skilled multi-axis machining and/or programming, putting them on a grinder or running simple mill parts is a waste of talent. Even if they need a little more training, it’s much more efficient to move that employee to the more complicated work instead of hiring another person, which you may have to train-in anyway.

Transportation:

Transportation is all of the unneeded movements of parts and materials. The shortest route from point A to point B is a straight line, anything else is wasting time. While it’s not always possible to do this in a machine shop, the shorter the distance parts and material have to travel the better.

Inventory:

This is similar to overproduction because having too big of an inventory takes up space and takes more machine time to run. If you’re making more parts than the order requires, it is considered wasteful inventory.

Motion:

Much like wasteful transportation of parts, a machinist should reduce wasteful motion as much as possible to be efficient. If you’re setting up a job, all the tools should be set-up and ready to go or on the workbench next to the machine. This can be done during cycle time of the previous job to save time. When loading and unloading parts in the machine during production, as well as part deburring, having everything close by or within reaching distance will reduce motion and save time in the long run.

Excessive Processing:

Like mentioned before, time is the biggest money breaker or maker, and if you’re spending too much time trying to perfect parts or orders when it is not needed, then you’re wasting time. If you have wide open tolerances on some or most of the part features, spending extra set-up and/or cycle time to try and get it right at the nominal number is waste. As long as all of the parts are within tolerance of the blueprint, they’re good. If the part doesn’t go together during assembly or function properly, it’s that customer’s job to fix the print, not the machine shop’s job.

Now, how can YOU as a Machinist benefit from all of this? This can help boost your reputation at your current job, as well as your resume. The harder you work at being more efficient, the more your boss/foreman will notice. This may result in better raises, a promotion, or benefits in various ways.

Although not all of these factors directly relate to you, suggesting them to higher authority may give you better recognition in the long run.

Do CNC Machinists Need To Go To School?

So you’ve decided that you want to be a full-time Machinist for a career, but you’re not sure if you can find a job without going to school… If you haven’t already, check out my article on CNC machinist training.

While many career’s start right after or during college these days, there are a lot of jobs that don’t necessarily require schooling. Years ago you could start out as a shop helper during weeknights while going to high school, but now it seems like you need take at least two years of post-secondary education to get any ‘real job’.

To answer the question plainly, no, you don’t NEED to go to school to be a full-time cnc machinist. There’s plenty of machinists that didn’t go to school and are doing well. In fact, there’s some guys that never took anything past high and ended up owning their own machine shop.

With that said, it may be hard to find a job in the manufacturing industry with little to no experience. In this case, the old saying, “It pays to know” couldn’t be more true. If you have a friend or a friend of a parent works in a local machine shop, ask them if there are any openings at that shop. If they don’t, that friend will usually suggest another shop or be on the lookout if they know you well enough.Do CNC Machinists Need To Go To School

Going to your local Tech school for Machining classes will definitely give you a head start, or an accelerated start if you just graduated from high school and already work in a manufacturing shop. You will be able learn all of your basic machining 101 knowledge, and then work your way up from there until you can program and make your own parts.

There’s shops out there that will start from scratch if they find a young and motivated worker, but the learning process will usually be more gradual over a longer period of time. Unfortunately, those can be hard to come by, and the wages probably won’t be enough to live off of.

One of the biggest problems is that most companies want someone with several years of machining experience, and don’t want to spend their time trying to train someone in, hoping that they will weed out the ill-performing machinists. While they may work some of the time, there’s no real way to tell how good of a machinist someone is until you give them work to do. You can take someone with 1-2 years of schooling and a year of on the job experience, and they might do better than another machinist that has been in the industry for 10+ years.

In the end, it’s up to YOU to decide what to do. The smartest route would be starting right off the bat when you graduate high school and going to a Tech school for machining, and possibly finding a small shop to work for at the same time. However, not everyone is young enough to do that. For those that are older and need a steady full-time job, there are people that take machining classes during the day, and go do to work at night. It can be gruesome, but if you work hard at it and really think that you want to pursue this great career, I encourage you to put the hammer down and quit slacking off!

Good luck!

CNC Machine Shop – What Is In It?

While every machine shop is different, you’ll see similar set-ups when you walk through them. There will usually be the main area where all of the CNC milling or turning centers are, as well as a section to deburr parts. Sometimes there will be deburring tools/machines next to the machine you’re running if the operator does all of the deburring.

Usually in a different area there will be a stock room with all of the raw materials needed for upcoming jobs. These few rooms or areas make up a CNC Machine Shop, which is usually a large industrial or steel building, as well as a small pole barn or garage, depending on how big the company is.

Stock Room

Round stock, square stock, and tubing are the most common, and they are usually 8 or 12 foot bars in length. There should also be a band saw in this same room so that someone can cut up the right size stock for each job. Most shops have an automatic horizontal band-saws so that they can cut a large quantity of parts in a short period of time with relatively close tolerances.

Machines

Machine Shop
Machine Shop

Depending on what kind of a machine shop you’re in, there’s a lot of milling machines that could be running. While milling and turning centers are the most common, there’s many more machines, as well as different variations of each.

A shop can have vertical or horizontal milling centers, depending on how complex their parts on, and if they’re a job shop or a production shop. Vertical mills are the most common because they’re cheaper and easier to use and set up.

Lathes are pretty similar, but they can be a flat-bed, slant-bed, multi-axis, or have live tooling for special jobs.

Other machines include, but not limited to: Wire EDM, waterjet, press brake, turret punch, CNC laser, as well as miscellaneous deburring machines (tumbler, straightliner, grinders).

Deburring

Like mentioned above, there will be some deburring tools/machines if the company wants to save money by doing all or most of it themselves. Often times there will be a drill press and grinder next to each mill so the operator can do most of the deburring right there in between cycle times.

The higher quality and quantity the parts, the bigger and better the deburring equipment will be. Giant tumblers/vibratory tubs are often used in large production shops for basic deburring. Media blasting is also common for parts if they are to be plated or coating with something. Zinc, chromate, anodizing, hardcoat/powdercoat, and nickel are just a few coatings that are done to machined parts to give them a better look, last longer, and/or function different.

Inspection Room

Clean Inspection Room
Clean Inspection Room

The inspection room should be separate and enclosed from the shop. If parts have close tolerances, there will be expensive inspection equipment, and the room will be temperature controlled so all of the readings are accurate and consistent.

Tools will include: a granite surface plate, height gage, CMM, bore gage, go/no-go gages for specific jobs, optical comparator, profilometer, thread gages, and gage pins. Not every job will have all of these tools, but some will have more.

Depending on how big the shop is, you (the Machinist), may or may not be inspecting your own parts. The more machines and tools you learn how to use, the better off you will be, so try to get in on how to use the equipment if there is an inspector at your shop.

Well, that’s the jist of what a CNC Shop has on the inside of it! Check out my other articles for tips on becoming a CNC Machinist. Stay tuned for more…