The Benefits of the Vertical Grinder
A vertical grinder is one of the two main types of grinders. The vertical type of grinder can be used to grind either flat materials or in the case of a plate and blade grinder, flat materials plus a plate and blade. The main difference between a vertical grinder and a horizontal grinder is that the vertical grinder can be used to grind materials both up and down. Also the vertical type is used for heavier work than the horizontal variety. Vertical grinders are operated by a hand crank on the front side of the machine and grind material all the way up to the blade.
In the case of a plate and blade grinder, the workpiece is ground all the way to the blade at the same time the grinding wheel is turning. In a vertical grinder, the workpiece is ground at the same time the grinding wheel is turning. This allows for less distortion of the workpiece as the grinding wheel turns. Also, when vertical grinding is used for large areas of the same diameter, the machine tends to run cooler, which also contributes to less distortion. However, some horizontal grinders do tend to run hotter than vertical grinders because of the large radial load they experience.
The two types of grinders fall into two groups: vertical and horizontal. Vertical grinders are made with two or more horizontal rotors. The workpiece can be ground at the same time these machines are running. This type of grinder will most commonly be used for small to medium sized items. The main advantage to this type of grinder is that it can grind both sides of the material allowing for greater material removal. Also, because these wheels tend to be less expensive than the ones used in a table saw, the cost of this type of grinding equipment is often considerably less.
A major disadvantage to the vertical grinding type of milling machine is the amount of material removed during each rotation. If the chuck is not well suited for the material being ground then the product may not have the same roundness, even though the teeth are the same size. In order to compensate for the amount of material removed each time the vertical grinder is used, the operator will need to operate the machine in a slower speed. This does not mean, however, that the finished product will be less round than it would be if the workpiece were ground using a different type of milling machine. In fact, the opposite is true. Since the vertical grinder is designed to move at a slower pace than a table saw, the end product will be of a much higher quality than it would be if the work were cut using the same amount of force but at a faster speed.
Some examples of vertical grinders are the Hitachi Electric Vertical Grinder and the Milwaukee Electric Vertical Grinder. These units are available in both single and two-wheel stand-alone units as well as along with the table saw in saw stand and chuck in hand applications. The two wheel units are better suited for softwood, but the single unit can be used in hardwood as well. Many professional wood turners choose to use a combination of both types of machines to provide the best of both circular and vertical milling.