Simucube 2 uses tailor made Sinusoidal AC Permanent Magnet Synchronous Motor – a motor type best known from precision industrial robotics. Tech comparison: Texas Instruments (pdf), Engineering Solutions.

Simucube DD motor has been FEM optimized for virtually zero torque ripple and cogging (the feeling of detents or jerks when rotated).

The motor also features special segmented stator construction to yield especially high power efficiency enabling constant high torque output without cooling fan and/or throttling.

Simucube 2 motor coils have been designed for the highest torque slew rate rating (Nm/ms) in the Direct Drive market. This gives an unparalleled response speed in demanding conditions where torque direction and amplitude change rapidly.

With wheel angle resolution of several millions of counts per revolution, robotics grade optical angle sensor is a jack-of-all-trades sensor when it comes to sensor performance: the highest precision, the lowest latency, and the highest immunity to interference. It’s not the cheapest choice among sensors, tho.

The importance of sensor precision becomes paramount when simulating the natural physical properties of a steering wheel.

• Simucube 2 Sport & Pro have 22 bit (4 million counts per revolution) BiSS encoder
• Simucube 2 Ultimate has 24 bit (16 million counts per revolution) Hiperface encoder, known from high-tech industrial robotics

Simucube motor current sensing is based on special current sense resistors that have near-zero temperature drifting and aging characteristics. As resistors are the most direct method of measuring current, they have certain characteristics important in torque control: practically zero noise, ideal linearity, and sub-microsecond response time.

HDRT yields detailed torque control capability at the high & low extremes of output torque regions. This allows the device to utilize the full 20 kHz torque controller bandwidth without having to rely on performance-degrading current sensing noise filters.

HDRT operates by varying current sensing amplifier gain on the go thus reducing noise to a fraction from normal. Simucube uses a best-in-class amplifier (spec pdf) with very low noise and drifting characteristics while having very high analog bandwidth.

As of 2023 Simucube is the only DD wheel utilizing such technology.

Simucube power stage consists of a low loss MOSFET (spec) based DC/AC inverter. High power efficiency allows high Direct Drive torque without throttling or cooling. As these big MOSFETs operate under a relatively light load, they also get the benefit of a decades-long lifetime.

Unusually high performance (216 MHz 32 bit ARM Cortex-M7, spec) CPU to take care of motor torque control and signal processing tasks with the priority they deserve. The whole time-critical Field Oriented Control pipeline is running under Real-Time OS (RTOS) at a constant 20 kHz refresh rate.

As a byproduct, a beefy processor ensures Simucube 2 keeps its industry-leading position through software upgradeability during the years to come.

Dedicated communications CPU (168 MHz 32 bit ARM Cortex-M4, spec) handling all USB, I/O, and Simucube Wireless Wheel communication.

With the dual CPU architecture,w Simucube eliminates time-critical code execution overlapping and therefore enables butter-smooth torque signal processing while simultaneously achieving the lowest possible USB latency.

Electrically isolated transfer of power and data separates all motor side electronics to make it immune to any external interference, and vice versa. Isolation also effectively eliminates ground loop issues.

Dedicated protection diodes on USB and I/O (spec pdf). Protection adds ruggedness against electrostatic discharges of up to 25 kilovolts. This exceeds the strength required by industrial standards, not to mention commercial electronics standards.

SWW allows hot-swapping SWW compatible wheels. SWW has zero electrical contacts between the wheel and wheelbase which eliminates the change of worn-out contact issues.