ETEL IL+/LM Linear Motor Selection and Integration Guide

K240 (motor type): 0=straight line, 1=rotation. This parameter affects the display of positional units (mm vs. rad) in ETEL Tools.

4.3 Initialization and commutation parameter adaptation

IL+(coreless) and LM (coreless) need to be treated differently in terms of initialization (Phasing) parameters:

IL+(Ironless): Due to the extremely low inductance of ironless motors, K98 (PWM voltage duty cycle) needs to be reduced during constant current initialization (K90=2) to prevent current overshoot. The manual suggests using K90=2 with appropriate K92 (current amplitude) and K94 (time).

LM (iron core): can choose "pulse initialization" (K90=1) or "constant current initialization" (K90=2). Pulse initialization produces almost no displacement and is suitable for vertical axis or finite stroke applications, but the accuracy is slightly lower (about ± 20% phase).

General recommendation: For motors installed vertically (whether IL+or LM), priority should be given to using small displacement initialization (K90=6) to avoid load sliding and collision with mechanical limits.

4.4 Homing Mode Selection

The zeroing of linear motors usually uses encoder reference pulses (Index) or external home switches. In the DSC controller:

Multi reference pulse encoder (such as LIDA series): K40=12/13 (with mechanical limit) or 20/21 (with limited search stroke), K75 (reference pulse spacing) needs to be set correctly.

Single reference pulse encoder: K40=8/9 (pure Index) or 10/11 (with limit switch).

Origin switch+Index: K40=34~39 (requires K58 to select limit signal source - DIN9/DIN10 or encoder's EHO/ELS signal).

4.5 Current Limitation and I ² t Protection

According to the continuous current and peak current in the motor data manual, set the protection parameters of the DSC controller:

K83 (overcurrent threshold): should be set to about 1.2 times the peak current of the motor (converted to internal units of the controller [ci]).

K84 (I ² t trigger current): usually set as the square of the continuous current multiplied by 0.8192 (see manual calculation formula).

K85 (I ² t integral limit): Calculated based on the duration of peak current to prevent motor or driver overheating.

Special reminder: If using a two-phase linear motor (instead of a three-phase motor), during short stroke reciprocating motion, if the current is concentrated on a few windings, the K84 value should be halved to avoid local overheating.

Selection Cases and Common Misconceptions

5.1 Case 1: High speed wafer inspection platform

Requirement: Load 2kg, acceleration 5g, uniform speed 1.5m/s, speed ripple<0.05%.

Selection: IL+series ironless motor (extremely light rotor, zero cogging force), paired with DSCDL low-voltage controller (± 36V).

Key parameters: K77 set to 3 (11 bit interpolation), K90=2 (constant current initialization), K40=8 (single index returns to zero).

5.2 Case 2: CNC milling machine Z-axis

Requirement: Load of 80kg, acceleration of 1.5g, peak thrust of 1500N.

Selection: LMG series iron core motor (high force density), paired with DSC2P high-voltage controller (325Vdc bus).

Key parameters: K90=1 (pulse initialization, vertical axis zero displacement), K40=0 (mechanical limit return to zero), K83 overcurrent threshold set to 120% of the motor peak current.

5.3 Common selection misconceptions

Misconception 1: Neglecting heat dissipation conditions and using "water cooling" parameters instead of natural cooling, resulting in severe insufficient actual sustained thrust.

Misconception 2: Underestimating the Impact of Force Fluctuations - Choosing an iron core motor incorrectly in applications that require nanoscale positioning, even though ETEL's patented design has significantly reduced force fluctuations, still lacks the zero fluctuation characteristics of ironless motors.

Misconception 3: Mismatched driver voltage level - Low voltage drivers (such as DSCDM) cannot drive high voltage motors, and vice versa.