CNC machine tools are necessary for manufacturing precision machined parts. Without the right machine tool, you won’t get the quality required for the specific industry.
Therefore, going with ideal CNC machine tools is the only way to move forward with your project. Here are some benefits you get by choosing the right CNC cutting tools:
- Zero defects and greater accuracy.
- Lower production costs.
- CNC machining tools produce little to no waste.
- Quicker assembly.
Well, this article covers a burning topic, how to select the CNC machine tools for your industry and ideal ways to calculate the cutting amount.
Let’s start..
Common Types of CNC Machining Tools Used for Manufacturing
CNC machine tools get used to create parts and designs, and there are plenty of types of CNC machine tools present in the market, but here are the most commonly used ones and the materials.
Popular CNC machining tools materials
- Carbon Steel
- HSS Steel
- Carbide
- Diamond
Types of CNC Machining Cutting Tools
The following are some of the most common CNC machining tools:
- End Mill
The end mill is the most commonly used tool for vertical CNC machining. End mills are capable of removing a large amount of material in a short period.
- Face Mill
Face mills have a solid body that houses multiple carbide inserts. Face mills get used to create flat sections on workpieces.
- Thread Mill
Thread mills get used to cut internal or external threads, and they may be more effective than taps at penetrating tough metals or asymmetrical parts.
- Drill Bit
A drill bit gets made up of a shaft and a cutting edge get used to drill holes in a workpiece. To perform various cutting operations, operators use various drill bits with CNC machines.
- Reamer
The function of a reamer is to enlarge existing holes in a workpiece, resulting in an exact hole diameter and excellent surface finish.
Tips to Choose CNC Machining Cutting Tools
The challenging thing for engineers is how to select the right tool to ensure the job gets done correctly. There are various factors to keep in consideration before going with the CNC cutting tool. Here are some tips that engineers should consider before selecting the machine tool:
- Production volume
In general, high-volume projects use specialty, high-end cutting tools, while low-volume jobs use more economy-level tooling. It all comes down to economies of scale, with the cost of high-end, feature-specific tooling justified by the large number of parts that the tool will produce.
- Workpiece material
The tool selection depends quite a lot on the workpiece material. Drills, mills, and taps get used to machine various features, and standard tooling is available for each tool type and material. Aluminum as a material has the highest machinability, so the aluminum tooling has higher surface feet per minute (SFM) specifications so that they can operate faster.
- Capacity of machine
Most cutting tools get used in various CNC machines. Engineers and operators understand that a higher horsepower machine (with a larger taper) allows them to use combo tools that can perform multiple functions.
Finding the best efficiency is primarily concerned with selecting the appropriate tool for the project’s requirements, as well as the machine’s ability and availability to run it. It’s a no-brainer if a machine can run multiple parts at once and the operator replaces three instead of one. You can run various parts on the machine and save manufacturing time.
- Combo possibilities
Multiple-feature tools can save a lot of money and time when it comes to CNC machining. When multiple tasks — three or four or more — can be completed by one tool, cycle time increases while the time required to change out the tooling decreases.
For example, a properly designed insertable combo tool can drill and chamfer potentially three different ways, completing the job in one pass with one tool rather than six (and six passes).
Cutting Quantity Calculation in CNC Machining
The principle of good cutting amount selection is that the primary goal of rough machining is to improve productivity, but economy and processing costs should get considered. The precise value should be determined using the machine tool manual, the cutting quantity manual, and personal experience.
- Cutting depth t
T equals the machining allowance when the rigidity of the machine tool, workpiece, and tool allows, which is a measure to improve productivity. A certain margin should get left for finishing to ensure the machining accuracy and surface roughness of the parts. CNC tools may have a slightly lower finishing allowance than standard ones.
- Cutting width L
L is generally proportional to tool diameter d and inversely proportional to cut depth. The general value range of L in economical CNC machining is L=(0.60.9)d.
- Cutting speed v
Increasing v is another productivity measure, but v is closely related to tool durability. The tool durability decreases sharply as v increases, so the tool durability primarily determines the choice of v.
Furthermore, cutting speed is closely related to the material to be processed. When milling the alloy 30CrNi2MoVA with an end mill, v can be around 8m/min. When milling aluminum alloy with the same end mill, v can get set to a value greater than 200m/min.
- Feed speed vF
vF should get chosen based on the part’s machining accuracy and surface roughness requirements, and the tool and workpiece material. Increased vF can also boost production efficiency. When the surface roughness requirement is low, vF gets increased.
vF can also be manually adjusted during the machining process using the trim switch on the machine control panel. Still, the maximum feed rate gets limited by the rigidity of the equipment and the performance of the feed system.
