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Mold manufacturers use many components for efficient high-speed machining (HSM) processes. HSMs have a powerful impact on CNC machines, cutting tools, controls, holders, and spindles. However, this impact on the toolpath and technical programming is often overlooked. Today, CAD/CAM technology is constantly evolving to meet the specific requirements of new toolpath strategies tailored to the HSM environment. HSM is a process that uses higher spindle feeds and speeds to remove material faster without compromising part quality. The main goal is to finish the mold to a net shape to improve geometric accuracy and surface finish so that polishing can be eliminated or reduced.

How it works

To facilitate high-speed machining, the following requirements are placed on the CAM software:

  • it should maximize program processing speed,
  • must minimize waste,
  • must maintain a constant load.

It should be noted that many CAM programs solve this problem by assuming that various specialized toolpath strategies can be used to make the part as specialized as possible.

What are the different types of toolpath strategies? 

There are different types of toolpath strategies that can be used to optimize CNC machining services. Here are some examples for CNC machine tools:


A tool path in which the tool follows the shape of a pocket using parallel paths separated by fixed steps. Benefits include that such a path provides a consistent and regular appearance, is the most straightforward default, and may not even be named in CAD.

Machining with a fixed „Z”

This strategy is beneficial for finishing, where the toolpath is traced around the machined contour with a fixed Z. It is usually used on steep walls. In contrast, in other cases, a different strategy is used. Less steep areas can be avoided by limiting the path to a wetting angle of 30 to 90 degrees. The benefit is undoubted that the element is of the same quality and height.

Pencil milling: 

A finishing technique is used mainly to address corners and recessed areas not discussed by toolpath strategies previously used in programs. Pencil milling allows the tool path to have the same diameter as the part being milled. In the absence of pencil milling or residual machining, operators are forced to identify corners that need to be machined. If you have efficient residual machining process, you don’t need pencil milling. The benefit is considered high-quality surface finish, convenience, and productivity.

Plunge Roughing: 

A roughing technique in which only the Z-axis passes through the cutting method, like repeatedly inserting a drill into the workpiece. The technique takes advantage of the fact that most machines are rigid in the Z-axis and can use higher feeds and/or larger cutters when used in this way. Plunge milling works best when the machine tool path is designed to provide bevel CNC milling machines. The benefit is productivity, which can be improved when roughing. By implementing a dynamic toolpath strategy, we can increase tool life, surface finish, and spindle life and improve overall cost efficiency and cycle time. You can implement any of the above strategies according to your requirements. 

Optimize your CNC machine 

„Optimize the CNC program” is the command you hear in your head after completing a machining program. It can be a tedious process, and you work blindly if you’re like me. Often a little too much, wasting a lot of time on changes that don’t improve significantly. As we all know, time is money, so I’ll try to free you up to work on rebuilding your program. Below is a list of quick, easy, and effective changes to your DATRON program. Here are some ways to optimize your CNC machine.

Leave the coolant on

This may not seem like much, but profits can increase. If you use coolant in your program, consider switching it from cut <0> to traverse <1> in the position/feed settings. You may not notice it, but a very short stop is programmed into the software to give you time to start spraying coolant. This command change will spray coolant between positioning movements, avoiding the initial stop. Now each duration may be only 1/10th of a second, but if you have 200 pullbacks in your program, you save only 20 seconds from the program, which is nothing. Optimize CNC programs by spraying coolant during positioning movements.

Change the cutting method

If you want to cut along a contour, consider changing your method. If you currently make plunge cuts, try using ramps. A ramp always keeps the cutting tool in the desired amount of material (except at the very beginning and end) and does not retract. Assuming the part has 200 retreats, the contour is cut on 20 different elements (10 retreats per part). With the ramp, you reduce this number from 200 to 20; if each withdrawal takes half a second, you save only 90 seconds.

Smooth function

If you’re doing complex sculpting or 3D contouring, you may have noticed that the machine slows down to follow all the contours strictly. It’s just executing commands, but smoothing can make a massive difference if you indulge a little in sticking to shapes. Optimize your CNC programs with smoothing features such as PerfectCut to smooth out jagged geometries. Smoothing takes jagged geometry and applies curves to the contour for smoother, more continuous motion. This is good for surface finishing and saves a lot of time because the machine doesn’t have to be slowed down on arcs compared to vectors. Using it is as simple as writing code in a macro, editing the preset (which works well in most cases), and hitting the „Start” button.

Add dynamics

Dynamic presets are one of the easiest ways to fail during a loop, so adjusting them with smoothing can give better results. A high dynamic range combined with a smoothing filter means minimal delay is required for fast turns, further reducing cycle time.

Reduce parameters

This is usually obvious, but it takes about 10 seconds to change the recall height from 0.5″ to 0.050″ (or less). Minimizing the curl height won’t save much time for a single wrap, but consider the bigger picture. Even if you only save 5 seconds per part, if you produce 20,000 pieces a year, you can save more than a day of machine work—every second counts.

Keep your tools in order

This may seem obvious, but try to organize your operations so that the tool is never used again in the program when you’re done. Sometimes this is unavoidable, but each tool change takes about 15 seconds. Consider using linked tools to reduce tool changes and create effective high speed machining. Most importantly, use the tools one at a time, not part by part, if you have nested elements. If you need to cut 24 pieces with four tools per part, you will spend 24 minutes for multiple tool changes or 1 minute to change all the tools at once. Rest machining can help improve work.