The metrological accuracy of a balancing machine depends on the natural-frequency separation of its rigid suspension pedestals, the low-frequency phase fidelity of its force/vibration sensors, and the plane-separation mathematics of its measuring unit. Engineered under Rootcastle, the REI series spans from 15-tonne turbine rotors spinning at 77 RPM (1.28 Hz) up to 120,000 RPM (2 kHz) automotive turbocharger cores.
Our hard-bearing machines are permanently calibrated: the operator simply enters the rotor geometry (distances A, B, C and correction radii R1, R2) and obtains exact gram and angle values for both planes on the very first run — no trial weight runs required. Every machine is delivered turnkey with our REI-PRO-04 24-bit 4-channel simultaneous DAQ controller, industrial touch PC, REI Studio software, and ISO 21940-21 (U_mar and URR) acceptance certification.
Benefits
Permanently calibrated hard-bearing architecture
Switching rotor types requires no trial-weight calibration; geometric inputs yield first-run correction vectors in both planes.
77 RPM to 120,000 RPM dynamic range
Our 1 GΩ JFET charge amplifier (0.015 Hz low-cutoff) ensures near-zero phase shift on 77 RPM slow turbines as well as 120,000 RPM VSR turbo rigs.
ISO 21940-21 U_mar & URR certification
Verified with a proving rotor prior to delivery for minimum achievable residual unbalance (U_mar) and unbalance reduction ratio (URR ≥ 90–95%).
In-house mechanics, DAQ electronics & software
The mechanical bed, suspension, drive panel, REI-PRO-04 DAQ board, and REI Studio software are engineered in-house by Rootcastle.
Process
Rotor envelope & capacity engineering
Defining rotor mass range (kg), maximum swing diameter (mm), bearing span, journal diameter and target ISO 21940-11 G grade.
Mechanical pedestal & drive manufacturing
Manufacturing belt-drive, cardan end-drive, or vertical spindle assemblies with isotropic hard-bearing force suspensions.
REI-PRO-04 DAQ & automation integration
Integrating 24-bit 4-ch simultaneous acquisition, isolated 0–10V VFD/valve control, CMP-Safety interlocks, and encoder angle indexing.
ISO 21940-21 FAT / SAT commissioning
Factory and site acceptance testing with a proving rotor for U_mar, URR and plane separation, followed by operator training.
Deliverables
- Turnkey horizontal, vertical or VSR balancing machine
- REI-PRO-04 24-bit industrial DAQ & control cabinet
- REI Studio bilingual (TR/EN) balancing & reporting software
- ISO 21940-21 U_mar & URR factory acceptance (FAT) & calibration certificate
- Full electrical/electronic schematics and operator manual
- Operator training and nationwide technical support
Applications
- Horizontal belt-drive machines (0.5 kg – 3,000 kg armatures, pumps, rolls)
- Horizontal cardan end-drive heavy-duty machines (1,000 kg – 15,000 kg turbines, fans, crushers, generators)
- Vertical single/two-plane machines (flywheels, pulleys, brake discs, clutches, fan impellers)
- High-speed VSR turbocharger core balancing stations (120,000 RPM with pneumatic valve & oil temp/pressure monitoring)
- Dedicated crankshaft and propshaft balancing rigs
Frequently asked questions
Should we choose a belt-drive or a cardan (end-drive) balancing machine?
For cylindrical medium-weight rotors (motor armatures, rolls, shafts), belt drive achieves the highest sensitivity because it introduces no coupling adapter error. For large high-windage fan impellers and heavy rotors (3–15 tonnes), cardan shaft end-drive provides the required torque and safety.
What is the minimum achievable residual unbalance (U_mar)?
Under ISO 21940-21, U_mar is the smallest residual unbalance the machine can reliably measure. On REI series machines, U_mar is engineered and verified with a proving rotor to sit below one quarter of the target G2.5 / G1.0 / G0.4 tolerance (U_mar ≤ U_per / 4).
Can automatic drilling or milling correction units be integrated?
Yes. Using the 8× isolated 24V high-side outputs and encoder angle-indexing on the REI-PRO-04 controller, our vertical and horizontal machines can integrate automated drilling/milling mass removal or laser marking stations.