The performance of a sheet metal laser cutting system is the result of careful optimization of the component design and machine features.
This article will help you better understand the technological choices made by the designers of 2D laser cutting machines with linear motors and guide you more consciously when considering the purchase of this type of system.
Differences between linear motors and rotary motors in laser cutting
If you are considering purchasing a new sheet metal laser cutting system and are unsure whether to choose linear or rotary motors, we recommend keeping this basic principle in mind:
Basic criteria for choosing a system with linear motors
Systems with linear motors can achieve much higher acceleration and jerk values (jerk is variation of acceleration) than those with rotary motors. However, the resulting increase on productivity depends on the type of part being processed.
With the same laser power, a system with linear motors becomes more productive:
- the thinner the metal sheet to be cut;
- the more complex are the geometries to be produced (i.e., geometries with rapid changes in direction and acceleration);
- the larger are the rapid movements, meaning laser-off displacements between one geometry and the next.
In general, linear motors provide a significant productivity gain for thicknesses below 5 mm.
For thicker materials, the gain remains noticeable when the cutting path includes long rapid movements; however, as thickness increases, this effect decreases because the transition time between geometries becomes much shorter compared to the actual cutting time, and its reduction has a negligible overall impact on the total cycle.
The graph shows the representative productivity curves for a sheet metal laser cutting machine with linear motors (green) and with rotary motors (gray), as a function of the material thickness being processed.
Linear motors: an excellent strategy for those looking to expand their 2D laser cutting machine fleet
The considerations outlined above lead to evaluating an important purchasing strategy, already adopted by many users of sheet metal laser cutting systems with rotary motors, who have chosen to acquire a sheet metal laser cutting machine with linear motors and dedicate it primarily to processing thinner parts with more complex geometries.
Naturally, the effectiveness of this strategy depends on the customer’s type of production. Subcontractors, for example, who work on very diverse parts in terms of thickness and geometry, can pair a linear motor machine with other rotary motor systems and assign each job to the most suitable solution.
For those who already own a fiber laser cutting system for sheet metal such as the LS7 or LS5, purchasing the new LS9 with linear motors can represent an additional advantage.
Moreover, thanks to Prometheus- MES (Manufacturing Execution System), job assignment to different machines can be performed easily and instantly via the drag & drop function in the planning interface: Planner.
In the video below, Martti Vesa, Product Sales Manager for sheet metal laser cutting systems at BLM GROUP, presents the LS9, the new sheet metal laser cutting machine with linear motors recently showcased at INNOVA 2025, BLM GROUP’s Open House.
Maintenance and reliability of laser cutting machines with linear motors
Linear and rotary motors have a completely different design concept, which also results in different motion transmission mechanics.
- Rotary motors follow the typical layout of a classic electric motor: a rotor that spins within a stator.
- Linear motors, on the other hand, feature a moving element that slides directly over a bed of permanent magnets arranged along linear guides.
Interior of the LS9 high-productivity sheet metal laser cutting system with linear motors.
With the rotary motor, the rotor’s motion must be converted into linear movement through intermediate elements such as ball screws, belts, or racks. The linear motor, on the other hand, can be connected directly to the moving element without the need for intermediate mechanisms.
The main advantages of linear motors are:
- no friction: there is no friction generated by gears, belts, or worm screws;
- no backlash: there are no mechanical components subject to wear that accumulate backlash over time;
- maximum efficiency: all the energy produced by the motor is transmitted directly to the carriage (moving element), without losses from intermediate components.
The result is a machine that requires less maintenance, fewer consumables to replace, and has greater long-term durability.
Linear motors: protection against cutting debris is essential
However, the maintenance and durability advantages of linear motors must take into account the fact that they are particularly sensitive to debris generated during laser cutting.
The guides contain long linear scales that the motor uses to precisely determine its position. If dirt or cutting debris accumulates on these linear scales, reading becomes difficult and the axis may go out of position, requiring operator intervention for cleaning.
If you are considering purchasing a sheet metal laser cutting system with linear motors, this is an aspect that must be carefully considered!
The solution is to choose systems in which the guides, motors, and linear scales are properly protected, preventing debris from entering and compromising the measurements. These solutions help avoid machine downtime and consequently increase overall availability and productivity.
The designers of the LS9: BLM GROUP’s sheet metal laser cutting system with linear motors, paid particular attention to this aspect, fully protecting the linear motor guides with aluminum bellows and isolating the measuring scales in a controlled atmosphere.
Operator removing the cut part from a laser cutting machine with linear motors. In front of him the aluminum bellows protecting the linear motor guides.
LS9, the fiber sheet metal laser cutting system with linear motors
Within the wide range of high-end sheet metal laser cutting machines, the LS9 stands out as one of the most high-performing systems on the market.
The result of over 35 years of experience in sheet metal laser cutting, the LS9 is the latest linear motor laser cutting system developed by BLM GROUP.
LS9 sheet metal laser cutting system with linear motors.
This system, in addition to ensuring high performance with accelerations up to 3.5 g and extremely high jerk values, integrates the innovative pallet change system already featured on the LS7, allowing the unloading of finished parts and loading of a new sheet in just 9 seconds, as well as all Active Tools functionalities for sheet metal laser cutting, which assist the operator in achieving consistently optimal cuts.
