Mistakes every Machinist Makes

Every machinist has experienced this. You set up your program, everything is set in the machine, you press start, and immediately anxiety begins to set in as you go check the outcome of your part. There is always a chance the machine was just out of tolerance and needed to be readjusted.  

This isn’t as bad as crashing the machine and spending your day trying to recover. There is a learning curve, and typical mistakes every machinist makes. These types of errors usually occur at the beginning of your career, however, even the most experienced machinist will not entirely escape the anxiety of selecting the wrong option for an offset. Or on a bad day missing the extra 0 that makes the difference between .0005 and .005. There are a few basic mistakes you can avoid to reduce that anxiety and actual machining errors.

Poor Maintenance of Machines

Both manual and CNC machines need to be meticulously cleaned and lubricated on a weekly to daily basis; otherwise, complications occur. A lack of proper maintenance and cleaning could enable a buildup of dirt and dust. As this may appear to be a simple hygiene issue, it can have lasting consequences. For instance, the material will slide around during the cutting process if there is a buildup of dirt. That prevents the machine from operating correctly and providing accurate instruction and precision. Additional wear on the machine parts will also reduce the life of the machine.

Insufficient lubrication can cause machine parts to stick together, or not move smoothly through their processes. This, too, can result in errors with precision and accuracy. Air blockages and overheating will ultimately lead to more problems and reduce equipment life. 

Improper Settings/Tools

Underlying problems must be investigated when one of your tools becomes blunt, your cutting coolant or lubricant is declining, or your tool is moving off the pace. The appearance of small burn marks around the corners and edges of the material will certify that something is indeed wrong. When your tool is moving too slowly, the material will be under the cutting edge for longer than ideal, creating burns and scars. Coolant manages a similar climate for the material; if it gets too hot, it will impact the corners and edges of the material with a rougher appearance. 

You will have to monitor the settings for each specific tool to prevent the scarring of the material. If your tool is blunt you may have similar problems with the finished product, and it’s a good time to purchase a new tool.

Incorrect Programming 

Improper programming is generally due to inexperience. This is a straightforward problem because the programming of a machine controls the manufacturing of a product.  If the programming is wrong, the production process will have problems. 

Unforeseen problems within programming can be hard to notice like accidentally enter the coding wrong. A programmer may be unaware of their mistake, but recognize that something is fundamentally wrong. An inexperienced employee could try power-cycling the machine by turning it off, then on again. This will force the machine to re-calibrate and can be helpful in some instances. The incorrect coding problem, however, remains unresolved and unnoticed. Full training for all employees on all machines is a necessity before setting up production to ensure they fully understand the process of programming. 

Vibration or chatter

When a CNC machine is experiencing excessive chatter or vibration it lowers the quality of the part, affects the precision, reduces tool life and impacts the service life of your machine. To resolve vibration/chatter issues with your machine there are several steps you can take. Ensure that the width/depth keeps the deflection below 1/1000th of an inch, fix the RPM of the process, and utilizing a balanced tool holder when spindle speeds are above 8,000 RPM are all effective solutions. 

When it comes to operating a CNC machine during a production run chances are you will encounter problems. The majority of the time the reason behind the problem can be detected and fixed by the machinist/machine operator. It is often a setup or programming error that every machinist makes. Sometimes it can be a mystery that forces you to be innovative with your solutions and a seasoned machinist can offer more value.