Same Sky NEMA08 to NEMA23 AMT112S Stepper Motors Review: Specs, Price and Applications
Updated: 4 days ago
Same Sky NEMA08 through NEMA23 AMT112S assemblies combine a LIN Engineering bipolar stepper motor with a Same Sky capacitive incremental encoder. The encoder supports programmable quadrature resolution and a digitally aligned index. These are motor-and-feedback assemblies: a suitable external drive and controller are still needed to create a closed-loop motion system.
Quick Verdict
Consider this range for an OEM axis that needs a compact stepper with accessible incremental feedback and a choice of motor sizes or windings. Its useful distinction is the packaged encoder, rather than an integrated amplifier. Select the exact model by its loaded torque-speed curve, phase current and mechanics; neither holding torque nor 4096 PPR establishes machine positioning accuracy.
Same Sky NEMA08 to NEMA23 AMT112S Stepper Motors at a Glance
Specification | Details |
Common motor architecture | Bipolar stepper, 1.8° full-step angle; LIN Engineering motor with Same Sky AMT112S encoder |
NEMA08: -13-01D / -17-01D | Holding torque 3 / 4 oz-in; phase current 0.60 / 0.80 A; body length 1.3 / 1.7 in |
NEMA11 models | Holding torque 9.2–16.6 oz-in; phase current 0.67 or 1.3 A depending on exact model; body length 1.26–2.01 in |
NEMA14: -10-04D / -10-08D | Both 7.5 oz-in holding torque and 1.02 in body length; phase current 0.45 / 0.35 A respectively |
NEMA17 models | Holding torque 42 / 63 / 83 / 110 oz-in; phase current and winding differ; body length 1.34–2.34 in |
NEMA23 models | Holding torque 85 / 170 / 270 oz-in; SD and PD variants have distinct currents and speed curves; body length 1.74–3.1 in |
Encoder signals | Single-ended CMOS A, B and Z; index once per revolution; not a differential line-driver interface |
Encoder resolution | 22 programmable choices from 48 to 4096 PPR; default 400 PPR |
Encoder supply | 4.5–5.5 V; typical 5 V; unloaded typical current consumption 16 mA |
Encoder accuracy | 0.2° typical in the datasheet; not a guaranteed complete-axis accuracy |
Motor rated-voltage entries | NEMA08/11/14/17: 24–48 VDC; NEMA23: 24–80 VDC; use a compatible current-regulated stepper drive |
Motor operating temperature | −20 to +50°C in the reviewed series datasheets |
Included control scope | Motor and encoder; external amplifier, motion controller, suitable cabling and supply arrangements required |
Price | Request a quote for the exact motor and encoder configuration |
Design and Engineering Assessment
The packaged encoder can remove a separate encoder-mounting task and provide rotor-motion feedback to compatible control electronics. It does not determine how that feedback is used. A controller may monitor following error, close a position loop or use the index for referencing, depending on its design. Specify the required control behavior before assuming that the words stepper servo describe a complete servo system.
Holding torque is a stationary capability under specified excitation, not the torque available at every running speed. The datasheets provide model-specific curves precisely because winding inductance, current and drive voltage change the operating envelope. Define acceleration, load inertia, process torque and dwell before comparing the maximum holding-torque numbers across frame sizes.
The five frames do not form a simple monotonic torque ladder. NEMA11 reaches 16.6 oz-in in the listed models, while the compact NEMA14 assemblies reviewed here are 7.5 oz-in. A flange designation describes a mechanical frame class rather than a guarantee of greater output than every smaller frame. Motor length, winding and the actual duty remain essential selection variables.
The incremental encoder observes the motor shaft. If a belt, screw or gearbox lies between motor and load, its backlash, compliance or slip remains outside that measurement point. A higher encoder count can improve command or measurement granularity without establishing load-position accuracy. Test the actual mechanism at the location where the process needs the positioning result.
NEMA08 and NEMA11: size and winding selection
NEMA08 offers two listed assemblies: -13-01D at 3 oz-in and -17-01D at 4 oz-in. Their 0.60 and 0.80 A phase currents and 1.3 and 1.7 inch body lengths distinguish them. The NEMA08 front shaft is 4 mm. Check the drawing and shaft loading before attaching an overhung pulley or coupling.
NEMA11 includes five models rather than one electrical configuration. For example, -20-01D and -20-02D both list 16.6 oz-in holding torque and 2.01 inch body length, but phase current is 0.67 versus 1.3 A. Their listed maximum optimal speeds are 11 versus 22 revolutions per second. Treat those catalog speed entries as model-specific guidance and verify the loaded curve.
NEMA14: the same torque can conceal different electronics needs
NEMA14-10-04D and NEMA14-10-08D both list 7.5 oz-in holding torque, a 5 mm front shaft and 1.02 inch motor body. The first uses 0.45 A per phase with 3.8 Ω phase resistance and 2.32 mH inductance; the second uses 0.35 A, 8.5 Ω and 5.77 mH. Those are materially different amplifier and speed-response considerations.
The corresponding maximum optimal speed entries are 30 and 20 revolutions per second. Do not combine the lower current from one winding with the higher speed of the other as if that were one configuration. Keep the complete ordering reference with its drive-current setting and performance curve.
NEMA17 and NEMA23: retain SD, PD and full model identities
The NEMA17 range spans 42, 63, 83 and 110 oz-in holding-torque selections. Several sizes provide SD and PD ordering choices, while the 110 oz-in NEMA17-23-01D has its own 2.0 A phase-current entry. Preserve the full model rather than creating one generic NEMA17 record that combines maxima from different windings.
The NEMA23-31-01SD and -31-01PD both list 270 oz-in holding torque and 3.1 inch body length. Their phase currents are 1.4 and 2.8 A; phase resistance is 4.5 and 1.1 Ω; inductance is 12.76 and 3.82 mH. The datasheet maximum optimal speed entries are 2 and 5 revolutions per second. The suffix changes the electrical selection even though the headline holding torque is the same.
PPR, quadrature counts and the encoder index
AMT112S is programmable from 48 through 4096 PPR, with 22 choices and a 400 PPR default. At 4096 PPR, a controller that counts all four quadrature edges obtains 16384 counts per revolution. This arithmetic must match the controller convention; entering 4096 where it expects four-edge counts changes the interpreted travel by a factor of four.
At that highest setting, one four-edge count represents about 0.022 degrees, while the datasheet lists 0.2 degrees typical encoder accuracy. These values describe different properties. Index alignment can establish a repeatable electronic reference relationship, but an incremental encoder does not become an absolute multiturn encoder simply because its zero position is digitally set.
Speed limits, programming and electrical interfaces
The encoder speed limit depends on resolution. The table lists 4000 rpm at 4096 PPR and 2500 rpm at 2500 PPR, with other settings permitting up to 8000 rpm. Those are encoder limits, not promises of useful motor torque at those speeds. Select a resolution supported by the complete motor cycle and the controller input bandwidth.
AMT Viewpoint software programs resolution and zero alignment without removing the encoder. The encoder uses a nominal 5 V supply and CMOS A/B/Z outputs. Use compatible controller inputs and the documented connector pinout; do not connect motor-bus voltage to the encoder. Cable length, noise environment and grounding need their own design because single-ended signals are not an RS422 differential interface.
Power stage and commissioning
The motor datasheets list 24–48 VDC rated voltage for the smaller frames and 24–80 VDC for NEMA23. A current-regulated stepper amplifier must be configured for the exact phase current and winding. Those system-level voltage entries do not authorize directly applying the bus across a low-resistance phase winding without current regulation.
Commission at controlled current and speed. Verify phase connections, encoder direction, quadrature scaling and index behavior before closing a feedback loop. Test power-cycle referencing, load disturbances and the chosen response to following error or an obstructed mechanism. A motor with feedback is not itself a machine safety controller.
Alternatives and ownership cost
Compare this motor-and-encoder arrangement with a conventional stepper plus a separately mounted encoder and with an integrated drive motor. The latter can reduce cabinet amplifier hardware but changes supply, interface and service requirements. Compare the complete axis at the same torque-speed cycle rather than treating those architectures as equivalent motor replacements.
Request a configuration-specific quotation and include the external drive, controller, encoder programming access, mating connectors and any transmission. Retain the programmed resolution and zero-alignment procedure with the complete model reference, so a replacement restores the qualified machine behavior.
Applications and Selection
Consider these assemblies for compact OEM positioning, indexing, dosing or inspection mechanisms where a bipolar stepper and incremental shaft feedback fit the machine architecture. These are engineering selection possibilities; the motor datasheets do not establish a certified application or a complete robot joint.
For Same Sky NEMA08 to NEMA23 AMT112S Stepper Motors, define the actual machine duty before selecting an ordering configuration. Include the required operating point, available installation space, environment and control interfaces. The specification table describes the product or family; the surrounding machine determines which of those features matters for the intended job.
Price and Value
Price: Request a quote for the exact configuration. Compare the product, compatible control equipment, required mechanical parts, cabling and commissioning as one installed system. A component price alone does not represent the cost of a working automation axis.
Evaluate an alternative against the same duty and acceptance criteria. Match the continuous operating requirement first, then compare transient capability, feedback, mechanical fit and support. This avoids choosing between superficially similar products whose ratings describe different operating conditions.
Pros and Cons
Advantages
Packages a stepper motor and capacitive encoder in one assembly
Programmable encoder resolution and index alignment without encoder removal
Five frame families and model-specific winding choices
Datasheets provide phase ratings, mechanics and torque-speed curves
Limitations
Requires an external drive and control system
Incremental motor feedback does not directly measure load position
Holding torque and encoder PPR do not establish running torque or axis accuracy
Model suffixes and signal-level compatibility require careful selection
Who Should Consider Same Sky NEMA08 to NEMA23 AMT112S Stepper Motors?
Consider this family when the machine already has, or will include, a compatible external stepper drive and a controller that can use incremental encoder feedback. Select the precise frame, length and winding against the loaded duty and confirm the assembled mechanism’s accuracy and fault response.
Same Sky NEMA08 to NEMA23 AMT112S Stepper Motors FAQ
Does this assembly include a servo drive?
No. It combines a LIN Engineering stepper motor with a Same Sky AMT112S encoder. An appropriate external amplifier and controller are required for a complete controlled axis.
Are CUI Devices and Same Sky references related?
The datasheets state that CUI Devices is now Same Sky. Preserve the actual ordering reference and datasheet revision when comparing old branding with a current quotation. The motor-and-encoder scope remains distinct from an integrated drive motor.
Does a larger NEMA number always provide more holding torque?
No. In these specific ranges, NEMA11 reaches 16.6 oz-in while the listed NEMA14 models provide 7.5 oz-in. Compare the exact motor, length, winding and loaded torque-speed curve.
Does 4096 PPR mean 4096 counts in every controller?
No. A controller using all four quadrature edges produces 16384 counts per revolution at 4096 PPR. Confirm the controller convention and programmed encoder setting before establishing motion scaling.
Is the digitally set zero an absolute multiturn position?
No. AMT112S is incremental, with one index pulse per revolution. Index alignment does not provide an absolute multiturn position after power loss; the machine needs its appropriate reference or position-retention strategy.
Are SD and PD versions electrically identical?
No. For example, NEMA23-31-01SD and -31-01PD share a 270 oz-in holding-torque entry but require 1.4 and 2.8 A per phase, with different winding resistance, inductance and speed behavior. Keep the full suffix.
Can the encoder use the motor power-supply voltage?
No. The encoder supply is specified at 4.5–5.5 V, nominally 5 V. Keep its power and CMOS signal levels compatible with the controller and separate from the motor-bus arrangement.
What is the price and what should be ordered?
Request a quote for the exact motor model and encoder configuration, then include the compatible amplifier, controller, programming access and cables. Specify phase current, supply architecture, quadrature scaling, shaft and loaded performance requirements.
Prices are indicative and may change. Confirm the final configuration, commercial terms and delivery schedule before ordering.
