Perhaps you have wondered if you need a CNC tool holder but are uncertain which would be right for you. It helps of course to understand not only what a tool holder is but what it is used for and why it is important. This is a question that is not that easy to answer for there really is no one correct answer.
You see, there is no such thing as one kind of CNC tool holder, for there are dozens of different kind of CNC tool holders, each of which allows the precision tools used by a CNC milling machine to be used in a different kind of way. But first perhaps it helps to understand just what a CNC milling machine is and what it does.
A very long time ago machines were made by hand; each piece of each machine was made separately and you never knew if the parts from one machine would fit in another machine for there was no way to ensure that the parts were uniform. Milling machines have changed all of that and CNC milling machines especially have had a big part in this.
A milling machine is what is used to machine solid materials that are then used to create many of the moving parts in machines, especially automobiles and aircraft. When these new machines became readily available it revolutionized machine making for now hundreds of machines could be made and the parts from any one machine would fit into any other machine. In addition additional parts (which would fit into all of the machines) could be made quickly and affordably. This was an incredible advancement for the production of uniform machine parts and was one of the things that enabled the concept of the assembly line to be such an incredible success.
Milling machines can be huge – taking up an entire room. Or they can be tiny little machines that fit on a desktop and do the tiniest detail work. These milling machines hold the piece of material being worked on stationary (though radially against the milling cutter). The work piece and cutter movements can be controlled to precise increments that allow incredibly detailed work to be accomplished. These precision increments can be attributed to the fact that today’s milling machines are operated by computer numerical controls which allow such specific measurements, most of which are too tiny for the human eye or hand to follow.
From slot and keyway cutting to planning, drilling, contouring, diesinking, there are many operations that a modern computer controlled milling machine can accomplish, and many of the extremely precise operations require tiny precision tools which are fitted into specifically made tool holders; holders crafted specifically to hold that precise tool and to be used in a highly specified way (moving sideways, rotating, moving only in certain arcs, allowing for specific types of movements). These tool holders can be purchased separately or bought in kits designed for use in specific kinds of situations. Each tool holder fits into the milling head so that it can be manipulated in ways specific to each CNC tool holder types.
CNC tool holders are precisely ground and have a male taper that fits exactly inside of the same machine’s female taper and is held in place with what is known as a retention knob or draw bar thread. The two basic taper-flange types on these machines include the V-flanges and the BT-flanges. While not interchangeable these types are quite similar. In each type, however, sizes of holders vary. The larger the size the larger the machine with the larger horsepower (or less precise action) the tool is designed for.
While these machines come in huge, room-sized models that are used for creating large machine parts, they can also be found in small, hobby sized CNC machine models such as that used by individuals crating things like remote controlled models and various other things that need machine parts and may need replacement parts eventually.
While there are horizontal models, most of today’s CNC milling machines are vertical mills that let the spindle move up and down on the Z axis which is a favorite position for small and precise things such as diesinking, engraving and creating relief sculptures by using tiny tools such as conical tools or ball nose cutters that further improve the precision of the mill’s abilities.
Perhaps one of the most intriguing devices is that of the multiaxis machine which allows the milling machine to move on two or more axis in addition to the normal three axes which allows asymmetric or even eccentric turning which can make them invaluable for artists and those who are looking to create unique, one of a kind machines. These multiaxis machines are so precise that they can exactly duplicate incredibly complex geometries such as the detailing of a human head or other complex rendition.
No matter what you are using your CNC milling machine for, you will find that by choosing the right CNC tool holder you can control your precision craftsmanship and ensure reproducible results from your machine made parts.