New Motor Drive System Provides High Accuracy Motion and RepeatabilityApril 14, 2020 by Robin Mitchell
This week Optimal Engineering Systems has released two new motor drive systems that provide high accuracy motion and repeatability.
The vast majority of motor drive systems are either linear, such as those found in CNCs, or rotary which drive drills and other tooling bits. Rotary motors can also be useful for rotating workpieces such as those on a CNC lathe but some applications require a high degree of accuracy in their rotation.
In these applications, a goniometer is required which is a rotational device that allows for a device to be set to a specific angle with high precision and repeatability.
Goniometer stages are typically driven by a stepper motor but will often be geared down to provide minute adjustments to the angle and will often have limit switches to prevent over-rotation.
They can also be reset to a specific angle with a high degree of repeatability. Examples of where goniometer can be highly beneficial include lasers, medical, and communications but also have applications in industrial automated systems.
Introducing the PR100-45-01 and PR100-45-02
This week, Optimal Engineering Systems released two new goniometer drive systems, the PR100-45-01 and PR100-45-02 with 01 being driven by stepper motors while the 02 version is driven by brushless servo motors.
The servo version of the motor drive system integrates a quadrature incremental optical encoder to provide a high degree of repeatability and accuracy.
The pitch axis (i.e. the lower stage), is the goniometer which has preloaded cross roller guides and a worm ratio gear drive that has a high ratio to provide smooth operation over the ±45 degree range.
Optimal Engineering Systems AK110-15-10 goniometer stacked stage. Image used courtesy of Optimal Engineering Systems.
The drives have an accuracy of 0.05 degrees and repeatability of ±0.01 degrees making them highly applicable to applications requiring both accuracy and repeatability. The systems also integrate limit switches to prevent overturning which not only improves reliability but also provides designers with peace of mind.
The upper stage is the roll axis and has a geared system with a 180:1 ratio for smooth operation.
Just like the lower stage, the upper stage also has an accuracy of 0.05 degrees and repeatability of ±0.01 degrees but also integrates a home signal for initialization.
Greater Emphasis on Reliability
Both axes on the motor drive systems have calibrated scales to show operates the current angle and the maximum speeds of the drives are 14 degrees/second for the stepper motor and 45 degrees/second for the servo motor. The knobs on the stepper motors can easily be replaced with optical encoders for position verification for applications that require a greater emphasis on reliability.
The PR100-45-01 stepper motor drive has a resolution that is dependent on the motor used and any additional optical encoders.
A resolution of 0.001 degrees can be achieved with the 01 if a stepper motor with 10 micro-steps per step is used or an encoder with a resolution of 500 cycles per revolution. The 02 that uses servos is ideal for applications that require a close loop system and fast speeds.