Rotary tables
Machining rotary-table indexing, simultaneous control, angular accuracy, torque and workpiece-support limits.
Tags: tooling, workholding, rotary-tables, indexing
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Haas's HRT160 lists 203 N·m continuous spindle torque and 136 N·m brake torque at 100 psi (6.9 bar). Maximum platter weight is 40.8 kg supported or 20.4 kg unsupported. Check whether the operation uses a stationary locked table or coordinated motion, and check overhang and load moment separately. Haas HRT160 load specifications.
Use Choosing workholding to compare location, support and restraint across fixture types.
Purpose and motion
Haas offers rotary axes for indexing and coordinated machining. The table must support the loaded fixture throughout the intended motion. Haas rotary introduction
| Use | Rotary behavior | Capability that remains separate |
|---|---|---|
| Index and cut | Move to an angle, then machine at that position | Holding stiffness and load capacity |
| Simultaneous machining | Rotate in coordination with other machine axes | Compatible CNC, drives and interpolation |
| Manual angular positioning | Position using a handwheel and scale | Scale graduation versus achieved accuracy |
| Tilting-rotary arrangement | Add another angular axis | Its own travel, torque and collision envelope |
Verify CNC interpolation capability separately from motorization. A brake holds position while engaged.
Drives and control interfaces
Sherline's 4-inch table family illustrates a worm-driven design: its 72:1 ratio produces 5° of platter rotation per handwheel revolution, with 0.1° handwheel graduations. The family includes manual, stepper-ready, motor-equipped and separately programmable-indexer versions. A motor mount does not itself include a motor, drive or integrated machine control. Sherline rotary tables
Haas's introduction calls a head plus separate Servo Control a semi-fourth-axis system. It separately lists true simultaneous fourth/fifth-axis control through the CNC without that Servo Control unit. These are Haas interface descriptions; a generic electrical connection or spare machine signal does not establish coordinated interpolation. Haas control arrangements
Kitagawa's RK201 is a roller-gear/cam-driven example. Its page distinguishes mechanical pneumatic clamping from holding through motor torque, so drive type and stationary locking method are separate specifications. Kitagawa RK201
Accuracy, repeatability and backlash
Haas's HRT160 product specification lists ±15 arc-seconds indexing accuracy, 10 arc-seconds repeatability, 30 arc-seconds backlash and 0.013 mm maximum runout. These are distinct properties of that model; they do not describe the same error or establish finished-part tolerance. Haas HRT160 specifications
Interpretation: angular accuracy concerns closeness to the commanded position; repeatability concerns returning to a position under the measurement conditions. Backlash concerns lost motion on reversal. Runout describes geometric variation rather than angular positioning. Display resolution, gear ratio and a handwheel graduation supply none of those quantities automatically.
An original small-angle comparison converts 15 arc-seconds to 15 / 3,600 = 0.0041667°, or approximately 0.000072722 rad. At a hypothetical 100 mm feature radius, the corresponding tangential displacement is 100 × 0.000072722 = 0.007272 mm, approximately 7.27 µm. This uses the cited angular magnitude only; mounting, axis location and fixture errors are additional. Angular magnitude: HRT160
Holding torque, drive torque and supported mass
The HRT160 page separately lists 203 N·m continuous spindle torque and 136 N·m brake torque at 100 psi/6.9 bar. Maximum platter weights are 40.8 kg with support and 20.4 kg unsupported. These values belong to the specified arrangement; supported mass, cutting torque and overturning moment are not interchangeable ratings. Haas HRT160 load specifications
For the RK201, Kitagawa lists 340 N·m pneumatic clamping torque at 0.5 MPa. It separately gives 108 N·m maximum continuous motor holding torque and 240 N·m instantaneous holding torque, explicitly scoped to its QUINTE controller; fourth-axis configurations differ. Its advertised 0.31 s for 90° indexing excludes pneumatic clamping and uses servo holding. That timing is not a complete clamp–move–settle machining cycle. Kitagawa RK201 specifications and notes
Check overhang, bearing moments and inertia in addition to payload and torque. Include the attached fixture and its restraint.
Worked example: seven equal divisions
Original ideal arithmetic using the cited 72:1 ratio: seven equally spaced positions require 360 / 7 = 51.428571…° per division. On that worm ratio, the corresponding handwheel motion is 72 / 7 = 10.285714… revolutions per division. Ratio context: Sherline
Ten whole turns alone would move the table 50°, leaving 1.428571…° of the division. This calculation explains the distinction between a reduction ratio and a practicable indexing method; it does not claim that the handwheel's graduations resolve every fractional division exactly. A controller's numeric input resolution likewise does not guarantee equivalent positioning accuracy.
Coverage and source dates
No technical issue dates were established for the cited product pages or Haas online introduction. Search timestamps and website copyright years are not technical editions. This article covers machining workholding tables, not transfer-machine indexing stations or drilling-rig rotary tables.
The sources do not establish universal positioning accuracy, speed, payload, cutting torque or controller compatibility. Machine travel, center height, mounting, fixture envelope, support, utilities and control options remain assembly-specific. Catalog features do not establish a shop's installed fourth/fifth-axis capability or approved machining setup.