Glossary of commonly used words in a CNC Machine Shop

Glossary - Commonly used word/terms

Word or Item

Description

Acetron

Acetron® GP is Quadrant's general purpose copolymer acetal and is the only porosity-free acetal product available today.

CNC

The abbreviation CNC stands for computer numerical control, and refers specifically to a computer "controller" that reads G-code instructions and drives a machine tool, a powered mechanical device typically used to fabricate components by the selective removal of material.

CRS

Cold Rolled Steel

Deburring

Deburring is a finishing method (sanding, grinding) used to remove burrs, the raised particles and shavings that appear when metal blanks are machined. Metal is frequently machined using many processes to create specific shapes and sizes.

Deburring is important for quality, aesthetics, functionality and smooth operation of working parts. It is also important for safety. Even a small notch can cause moving parts to catch, creating the potential for accident, injury or unnecessary delay in production. Rough edges can also cause injury when individuals are required to handle blanks.

Delrin

Polyoxymethylene (POM), in the USA also commonly known under DuPont's brand name Delrin, is an engineering plastic, a polymer with the chemical formula -(-O-C H₂-)_n-. It is often marketed and used as a metal substitute, Delrin is a lightweight, low-friction, and wear-resistant thermoplastic with good physical and processing properties and capable of operating in temperatures in excess of 90 degrees Celsius (approx 200 degrees Fahrenheit). According to the material safety data sheet from DuPont, the material has a slight odor of formaldehyde.^[1]

It is also known as polyacetal, acetal resin, polytrioxane, polyformaldehyde, and paraformaldehyde; the latter term is usually restricted to the short-chained polymer. The plastic is sold under the trade names Kepital, Celcon, Hostaform and Ultraform^[2], the last three being copolymers.

HRS

Hot Rolled Steel

JEC

Journey Electronics Corp. – creator and manufacturer of the Moisture/Hardness Control System.

KanBan

An inventory control system created by Toyota in late 1940.

Origin: The term kanban describes an embellished wooden or metal sign which has often been reduced to become a trade mark or seal. Since the 17th century, this expression in the Japanese mercantile system has been as important to the merchants of Japan as military banners have been to the samurai. Visual puns, calligraphy and ingenious shapes — or kanban — define the trade and class of a business or tradesman. Often produced within rigid Confucian restrictions on size and color, the signs and seals are masterpieces of logo and symbol design. For example, sumo wrestlers, a symbol of strength, may be used as kanban on a pharmacy's sign to advertise a treatment for anemia

In the late 1940s, Toyota was studying U.S. supermarkets with a view to applying some of their management techniques to their work. This interest came about because in a supermarket the customer can get what is needed at the time needed in the amount needed. The supermarket only stocks what it believes it will sell and the customer only takes what they need because future supply is assured. This led Toyota to view earlier processes, to that in focus, as a kind of store. The process goes to this store to get its needed components and the store then replenishes those components. It is the rate of this replenishment, which is controlled by kanban that gives the permission to produce. In 1953, Toyota applied this logic in their main plant machine shop.^[4]

Operation: An important determinant of the success of "push" production scheduling is the quality of the demand forecast which provides the "push". Kanban, by contrast, is part of a pull system that determines the supply, or production, according to the actual demand of the customers. In contexts where supply time is lengthy and demand is difficult to forecast, the best one can do is to respond quickly to observed demand. This is exactly what a kanban system can help: it is used as a demand signal which immediately propagates through the supply chain. This can be used to ensure that intermediate stocks held in the supply chain are better managed, usually smaller. Where the supply response cannot be quick enough to meet actual demand fluctuations, causing significant lost sales, then stock building may be deemed as appropriate which can be achieved by issuing more kanban. Taiichi Ohno states that in order to be effective kanban must follow strict rules of use ^[5] (Toyota, for example, has six simple rules) and that close monitoring of these rules is a never-ending problem to ensure that kanban does what is required.

A simple example of the kanban system implementation might be a "three-bin system" for the supplied parts (where there is no in-house manufacturing) — one bin on the factory floor, one bin in the factory store and one bin at the suppliers' store. The bins usually have a removable card that contains the product details and other relevant information — the kanban card. When the bin on the shop floor is empty, the bin and kanban card are returned to the store. The store then replaces the bin on the factory floor with a full bin, which also contains a kanban card. The store then contacts the supplier and returns the now empty bin with its kanban card. The suppliers inbound product bin with its kanban card is then delivered into the factory store completing the final step to the system. Thus the process will never run out of product and could be described as a loop, providing the exact amount required, with only one spare so there will never be an issue of over-supply. This 'spare' bin allows for the uncertainty in supply, use and transport that are inherent in the system. The secret to a good kanban system is to calculate how many kanban cards are required for each product. Most factories using kanban use the coloured board system (Heijunka Box). This consists of a board created especially for holding the kanban cards.

Here is another example of kanban thinking: in the production of a widget, the operator has two shelves, one on either side of their workplace. The raw materials can be designated to arrive on one shelf and the finished articles placed on the other. These shelves can then be designated to act as kanbans. The outgoing kanban signals the customer's need so that when it is empty, the operator must produce another widget.

The kanban is sized so that it can only hold a fixed number of items decided by the customer needs (usually one). When the operator begins work, he takes the raw material from the incoming kanban, which when seen by the supplier, signals that the customer needs one more.

So, kanban can be said to have several basic principles: (1) only produce products to replace those consumed, (2) only produce products based on signals from consumers, and (3) containers must contain an identical number of parts.

MHCS

Moisture/Hardness Control System manufactured by Journey Electronics Corp

Penetrometer

An instrument for measuring the firmness or consistency of a substance. The penetrometer manufactured by Journey Electronics Corp measures the kilogram per square centimeter for hardness of clay.

Reverse Engineering (RE)

Reverse engineering (RE) is the process of discovering the technological principles of a device, object or system through analysis of its structure, function and operation. It often involves taking something (e.g. a mechanical device, electronic component, or software program) apart and analyzing its workings in detail, usually to try to make a new device or program that does the same thing without copying anything from the original.

In the United States and many other countries, even if an artifact or process is protected by trade secrets, reverse-engineering the artifact or process is often lawful as long as it is obtained legitimately. Patents, on the other hand, need a public disclosure of an invention, and therefore patented items do not necessarily have to be reverse engineered to be studied. One common motivation of reverse engineers is to determine whether a competitor's product contains patent infringements or copyright infringements.

SolidWorks

SolidWorks is a 3D mechanical CAD (computer-aided design) program that runs on Microsoft Windows and was developed by SolidWorks Corporation - now a subsidiary of Dassault Systèmes, S. A. (Suresnes, France). SolidWorks is a parametric feature-based solid modeler, using the Parasolid geometric modeling kernel. SolidWorks was introduced in 1995 as a competitor to CAD programs such as Pro/ENGINEER, I-DEAS, Unigraphics, CATIA, and Autodesk Inventor, and is currently one of the leading products in the "midrange" or "mainstream" mechanical CAD market.^[1]

UHMW

Ultra high molecular weight polyethylene (UHMWPE), also known as high-modulus polyethylene (HMPE) or high-performance polyethylene (HPPE), is a thermoplastic. It has extremely long chains, with molecular weight numbering in the millions, usually between 2 and 6 million. The longer chain serves to transfer load more effectively to the polymer backbone by strengthening intermolecular interactions. This results in a very tough material, with the highest impact strength of any thermoplastic presently made. It is highly resistant to corrosive chemicals, with exception of oxidizing acids. It has extremely low moisture absorption, has a very low coefficient of friction, is self-lubricating, and is highly resistant to abrasion (15 times more resistant to abrasion than carbon steel). Its coefficient of friction is significantly lower than that of nylon and acetal, and is comparable to that of teflon, but UHMWPE has better abrasion resistance than teflon. It is odorless, tasteless, and nontoxic.

Polymerisation of UHMWPE was commercialized in the 1950s by Ruhrchemie AG, which changed names over the years; today UHMWPE powder materials are produced by Ticona. UHMWPE is available commercially either as consolidated forms, such as sheets or rods, and as fibers. UHMWPE powder may also be directly molded into the final shape of a product. Because of its resistance to wear and impact, UHMWPE continues to find increasing industrial applications, including the automotive and bottling sectors, for example. Since the 1960s, UHMWPE has also been the material of choice for total joint arthroplasty in orthopedic and spine implants [1].

UHMWPE fibers, commercialized in the late 1970s by the Dutch chemicals company DSM, are widely used in ballistic protection, defense applications, and increasingly in medical devices as well.

Waterjet

A water jet cutter is a tool capable of slicing into metal or other materials using a jet of water at high velocity and pressure, or a mixture of water and an abrasive substance. The process is essentially the same as water erosion found in nature but accelerated and concentrated by orders of magnitude. It is often used during fabrication or manufacture of parts for machinery and other devices. It has found applications in a diverse number of industries from mining to aerospace where it is used for operations such as cutting, shaping, carving, and reaming.

Frecon Technologies, Inc.

9319 Princeton Glendale Road, Hamilton, OH 45011

Phone: 513-874-8981 Fax: 513-874-8982

e-mail: mail@frecontechnologies.com

Located in Southwestern Ohio - near Cincinnati, Dayton, Franklin, Middletown, Covington, Newport, Northern Kentucky, Southern Indiana