Precision Surface Grinder Basics - How to Grind Fast and Accurate?
Precision surface grinding is a process used to hone and improve the quality of metal parts. It does this by removing excess amounts of material per project specifications.
The process can be performed on a variety of materials and is often preferred over milling because it produces a more accurate surface finish. However, High Precision Surface Grinder isn't for everyone and requires some knowledge to succeed.
Basics
In a nutshell, surface grinders use a rotating abrasive wheel to finish the flat surface of metallic or nonmetallic materials. This process removes the oxide layer and impurities from the workpiece, which will make it look more refined.
There are two basic types of surface grinders: rotary and horizontal-spindle grinders. The rotary type has a head that rotates the grinding wheel on a vertical axis, and a table moves the work piece underneath it to cut.
This grinding method is a good choice for applications that require high precision. This includes pins, pistons, bearing races and many other components.
Automatic surface grinders operate by executing repeated side-to-side passes, with each repetition removing a tiny fraction of the material from the metal part. This incremental removal allows precision surface grinders to produce a precise surface without the vibration and noise that accompanies metal removal by turning.
Variables
In the case of precision grinding, there are many variables that affect how the machine will produce a surface finish. These include feed, wheel speed and the abrasives used.
The first variable, feed, is the rate of movement along each axis. It can be measured in sfm or m/s.
Interestingly, in the case of precision grinding, wheel RPM is not usually as important as it is in other machining applications, because grinding operates at more or less constant speed.
The other variables that can influence how a precision surface grinder will produce a surface finish are wheel type, grit size and bond material. The hardness of the wheel, abrasive material and the structure of the wheel are factors to consider as well.
Workholding
Precision surface grinders are used to create flatness and parallelism at a high degree on the surfaces of parts that are relatively small. These parts are usually made as components of a complex machine and have very fine tolerances.
To achieve this high level of accuracy, Double Surface Grinding Machine must be performed in a controlled environment with the workpiece held securely at all times. Various workholding methods are available, ranging from static jaw/collet chucks to electro-permanent magnetic chucks.
Perimetric workholding is one of the most accurate and repeatable methods. This system employs the regulating roller and guide blade, but instead of placing them in a static position, they are positioned precisely on an additional axis, running relative to the grinding wheel.
This method of workholding eliminates setup misalignments, which can introduce runout and taper during grinding. Additionally, perimetric systems use tension rollers that ensure solid contact of the workpiece to both the guide blade and regulating roller.
Coolant
The coolant used in Precison Double sided grinder machine lubricates the tool and reduces friction between the workpiece and tool. This helps to extend the life of the tool and improves surface finish on the workpiece.
To achieve this, a coolant lubricant (oil or emulsion) is introduced into the machine tool's machining zone via nozzles. The coolant lubricant then absorbs process heat and guides it away from the machining zone, thereby improving machine reliability.
Throughout the machining process, a coolant lubricant may also perform other tasks within the machine tool, such as cleaning the grinding wheel of machining residues, flushing out chips from the machine or extinguishing the spark jet. This is done to ensure the best possible performance of the machining task and optimum grinding accuracy.
The optimum cooling and lubrication combination depends on the roll material ground, the grinding wheel specification and the application. Synthetic mixtures are preferred for steel, stainless steel and aluminum rolls, while petroleum-based soluble oil and straight oil are good options for brass, bronze, titanium, nickel and other exotic metals.