Flat BLDC motor
Run the calculator first. This single canonical page answers the 1 horsepower flat servo motor alias by converting horsepower into torque, cooling risk, duty-cycle limits, and RFQ evidence.
Evidence reviewed: June 5, 2026
Alias
merged
1 hp at 1800 rpm
3.96 Nm
Primary risk
cooling
Result feedback
Deterministic screenEmpty state: defaults are loaded
Run the screen to convert the 1 horsepower flat servo motor query into continuous torque, thermal derating, peak torque, and an RFQ next step.
Next action
Use the calculator, then request an RFQ review if speed, cooling, drive voltage, or continuous torque condition is unknown.
Request flat motor reviewLimit: cooling derate and peak multipliers are page heuristics, not standards. This tool does not replace a torque-speed curve, thermal model, servo drive check, bearing load review, or encoder selection.
Report summary
The tool gives an immediate result. This summary shows how to interpret it and why the 1 horsepower flat servo motor phrase belongs inside the flat BLDC motor canonical page.
| Decision point | Practical answer |
|---|---|
| What the tool answers | Whether a 1 hp flat BLDC or flat servo target is plausible from power, speed, size, duty, and cooling inputs. |
| What the report adds | Why horsepower alone is insufficient, which specs to request, how flat BLDC compares with frameless servo and pancake alternatives, and where risk remains. |
| Best-fit user | OEM engineers, sourcing teams, and machine builders preparing an RFQ or sanity-checking a compact servo motor package. |
| Poor-fit user | Anyone trying to buy from horsepower alone without speed, continuous torque, cooling condition, drive voltage, or feedback requirements. |
Key conclusions
These conclusions connect the calculator output to engineering and sourcing decisions. Values are screening numbers unless supplier test conditions are stated.
745.7 W
NIST lists mechanical horsepower, defined as 550 ft-lbf/s, as 745.6999 W. That only gives power; the motor still needs speed, torque, cooling, duty, voltage, feedback, and mounting data.
Evidence: NIST SP 811 conversion factors, reviewed June 2026
3.96 Nm
Using T = 9550 x kW / rpm, a 1 hp motor at 1800 rpm needs roughly 3.96 Nm before thermal derating. At lower speed, torque demand rises quickly.
Evidence: Standard motor sizing equation used in the page calculator
heuristic
The calculator uses 65%, 82%, and 95% cooling factors only to force a conservative review. Public supplier guidance shows frameless motors rely on the host housing and heat sink, so final continuous torque must come from supplier curves.
Evidence: Kollmorgen frameless integration guidance, reviewed June 2026
S1/S3
IEC 60034-1 treats S1 as continuous running duty and S3 as intermittent periodic duty. If no duty is declared, the standard context assumes continuous running duty, so a 1 hp intermittent axis cannot be compared with an S1 motor without the cyclic duration factor.
Evidence: IEC 60034-1 duty-type definitions, reviewed June 2026
counterexample
Public Parker P-Series data describes compact 40-80 mm brushless servos through 1 kW, with continuous stall torque up to 3.18 Nm. That is below the 3.96 Nm needed for 1 hp at 1800 rpm before derating, so headline power alone can hide a torque mismatch.
Evidence: Parker P-Series public product data, reviewed June 2026
single URL
A separate 1 horsepower flat servo motor route would compete with the flat BLDC motor page while answering the same sizing and procurement intent.
Evidence: OpenSpec alias-merge decision for this change
A flat motor trades axial length for diameter. The same 1 hp target can work or fail depending on speed, heat path, and servo integration.
Package logic
A short axial stack can still carry useful torque, but only when the larger diameter, mounting heat path, feedback package, cable exit, and drive voltage all fit the machine.
| Step | Decision use | Risk controlled |
|---|---|---|
| Power conversion | Convert 1 hp to 0.7457 kW so the page can calculate torque from speed. | Horsepower without rpm hides the actual torque requirement. |
| Torque calculation | Use T = 9550 x kW / rpm for the continuous torque target before derating. | At low rpm, a 1 hp target may demand too much torque for a thin axial package. |
| Cooling derate | Apply a conservative screening derate for natural convection, forced air, or conductive mounting. | The derate is not a catalog value; it only flags when the actual heat path must be proven. |
| Duty and peak check | Estimate peak torque from the selected duty case and mark short-duration assumptions clearly. | Peak torque without duration, current limit, and bus voltage is not a servo guarantee. |
| RFQ evidence | Turn the result into a supplier checklist: curve, heat path, encoder, drive, insulation, and mounting data. | A same-power motor can fail mechanically, thermally, or electronically. |
Evidence audit
This pass separates verified public facts from screening assumptions. That matters because a 1 horsepower flat servo motor query can otherwise overtrust a horsepower label and ignore thermal or duty conditions.
| Claim | Public fact | Decision use | Status |
|---|---|---|---|
| Mechanical horsepower conversion | NIST SP 811 lists horsepower (550 ft-lbf/s) as 7.456999 E+02 W. | Use 0.7457 kW for the calculator and avoid mixing mechanical, electric, metric, or boiler horsepower. | Verified public conversion |
| Continuous vs intermittent duty | IEC 60034-1 defines S1 as operation long enough to reach thermal equilibrium and S3 as repeated on/rest cycles with a cyclic duration factor. | Treat an undeclared 1 hp target as continuous until the supplier states S3/S4/S5 duty and duration. | Verified standard context |
| Flat/frameless thermal path | Kollmorgen guidance says frameless stators are embedded in the machine and need adequate heatsinking; their article calls out 4-6 mm nearby wall thickness and thermal sensors as design considerations. | Ask whether the continuous curve assumes a housing, cold plate, ambient temperature, or specific winding limit. | Supplier guidance, application dependent |
| Compact servo power does not guarantee continuous torque | Parker public P-Series data states compact 40-80 mm brushless servos are available through 1 kW, while continuous stall torque spans 0.16-3.18 Nm. | For 1 hp at 1800 rpm, compare required 3.96 Nm before derating against continuous torque at rated speed and cooling condition. | Public counterexample |
| Universal 1 hp flat servo SKU | No reliable public standard defines a universal 1 horsepower flat servo motor package, diameter, encoder, or drive voltage. | Use this page as an RFQ intake and require supplier-specific torque-speed curves before buying. | Pending confirmation / no reliable public data |
Updated: June 5, 2026. Evidence from public standards and supplier pages can frame the question, but it cannot certify a specific motor without the supplier's curve and the real machine heat path.
Architecture comparison
The phrase 1 horsepower flat servo motor can point to several architectures. The table keeps the comparison on one page so the keyword does not split into competing thin URLs.
| Option | Best for | Tradeoff | Ask supplier for |
|---|---|---|---|
| Flat BLDC motor | Compact rotary axes where controller and feedback can be selected separately | May need added encoder and drive tuning for servo behavior | Torque-speed curve, winding data, Kv/Kt, thermal mounting condition |
| Flat servo motor | Closed-loop positioning, indexing, and coordinated motion | Higher integration cost; feedback and drive compatibility matter | Encoder type, drive match, peak duration, inertia, brake option |
| Frameless torque motor | Integrated machine structures with custom bearings and heat paths | Requires mechanical integration and rotor/stator alignment control | Rotor ID/OD, stator OD, air gap, mounting temperature, FEA assumptions |
| Pancake brushed DC motor | Simple low-cost prototypes where brush wear is acceptable | Brush maintenance, lower control sophistication, and less clean-room fit | Brush life, commutation limits, duty rating, replacement availability |
Inputs: 1800 rpm, 120 mm OD, 45 mm stack, forced air, intermittent duty
Result: Plausible first-pass flat servo target. Validate peak current duration and gearbox or direct-drive inertia.
Inputs: 300 rpm, 160 mm OD, 40 mm stack, natural convection, continuous duty
Result: Likely torque-heavy for a thin package. Consider larger diameter, conductive cooling, or frameless torque motor architecture.
Inputs: 1200 rpm, 95 mm OD, 35 mm stack, natural convection, low noise requirement
Result: Thermal and acoustic review needed. Ask for winding temperature at mounting condition and cogging torque data.
Inputs: 3600 rpm, 100 mm OD, 30 mm stack, conductive plate, continuous duty
Result: Power density may be feasible, but voltage headroom, rotor containment, and bearing load need supplier evidence.
| Risk | Impact | Mitigation |
|---|---|---|
| Power-only selection | Same 1 hp rating can mean very different torque, current, and package size | Always pair hp with rpm, continuous torque, and thermal condition. |
| Catalog heat-sink mismatch | Motor overheats in the real machine despite matching the catalog power | Request continuous torque at the actual mounting temperature and cooling path. |
| Peak torque overuse | Drive trips, winding temperature rises, or magnets demagnetize after repeated moves | Define peak duration, duty cycle, RMS current, and acceleration profile. |
| Servo integration gap | A BLDC motor may not behave as a servo without suitable feedback and drive tuning | Specify encoder, commutation method, drive voltage, and controller compatibility. |
| Mechanical envelope omission | Brake, encoder, flange, cable exit, or bearing loads break the thin package assumption | Include full mechanical stackup, not only motor OD and active length. |
| Supply substitution | Alternate windings or magnets change Kt, back EMF, heat, and control behavior | Lock winding code, magnet grade, test limits, and revision traceability. |
Known and unknown
The calculator intentionally stops before pretending to know supplier-specific thermal, winding, encoder, and drive limits.
Power conversion, torque target at speed, input boundary warnings, screening derate, and RFQ checklist.
Use for first-pass feasibility and supplier intake.
Continuous curve at mounting temperature, peak duration, winding code, thermal resistance, insulation class, encoder option, and drive current limits.
Do not approve production selection until these are supplied.
RMS current over the real move profile, housing temperature, acoustic behavior, cable routing, bearing load, and control-loop stability.
Prototype or simulate with the final machine structure.
There is no trustworthy public dataset proving a universal 65/82/95% cooling derate across all flat BLDC or flat servo motors.
Keep derate factors labeled as conservative heuristics and replace them with supplier thermal data when available.
Evidence and sources
Public standards and supplier education pages help frame the sizing process, but the final motor choice still depends on supplier-specific curves, stated duty type, and application tests.
| Source | Used for | URL |
|---|---|---|
| NIST Guide to the SI, Appendix B.9 | Mechanical horsepower conversion: horsepower (550 ft-lbf/s) to watt = 7.456999 E+02. | https://www.nist.gov/pml/special-publication-811/nist-guide-si-appendix-b-conversion-factors/nist-guide-si-appendix-b9 |
| NEMA MG 1 motor rating context | Why motor nameplate power requires rating conditions and does not replace application sizing | https://www.nema.org/standards/view/motors-and-generators |
| IEC 60034-1 rotating electrical machines duty context | S1 continuous duty, S3 intermittent duty, and why undeclared duty cannot be treated as a peak servo guarantee. | https://webstore.iec.ch/en/publication/28145 |
| Kollmorgen frameless motor integration guidance | Thermal path, housing integration, and why frameless/flat motor continuous torque depends on mounting. | https://www.kollmorgen.com/en-us/blogs/have-you-considered-frameless-motor |
| Parker P-Series compact brushless servo public data | Counterexample that compact servo power range and continuous torque range must be read together. | https://ph.parker.com/us/17052/en/low-power-compact-brushless-servo-motors-p-series |
| Kollmorgen TBM frameless motor public product data | Example of supplier data fields to request: OD, continuous stall torque, peak stall torque, voltage, winding temperature, and stack lengths. | https://www.kollmorgen.com/en-us/products/motors/direct-drive/tbm-series/ |
Public evidence is insufficient for a universal 1 hp flat servo SKU. Treat the page as a structured intake and confidence screen, then qualify the actual motor with supplier data and application tests.
FAQ
The FAQ keeps the alias phrase, sizing method, servo integration, and qualification boundaries together on the canonical page.
Not exactly. A flat BLDC motor describes the motor architecture, while a flat servo motor usually adds feedback, drive compatibility, and closed-loop control requirements. This page keeps both on one canonical flat BLDC motor URL because the sizing intent overlaps.
About 3.96 Nm before thermal derating, using NIST mechanical horsepower conversion and T = 9550 x kW / rpm.
Power equals torque times speed. The same 1 hp rating needs much more torque at 300 rpm than at 3600 rpm, which can force a larger diameter, longer stack, gearbox, or different motor architecture.
No. You need continuous torque, speed range, peak torque duration, voltage, current, cooling condition, duty cycle, feedback type, mechanical envelope, and environmental constraints.
Natural convection is risky when the motor is enclosed, runs continuous torque, sits near a heat source, or uses a thin axial package with limited surface area. The page derate is a conservative screen, not a public standard value.
A flat motor usually trades axial length for larger diameter. That helps thin machines but can change inertia, mounting, heat flow, and cable-routing constraints.
No. Encoder choice depends on positioning accuracy, commutation method, safety needs, noise immunity, drive compatibility, and available axial space.
Use the intermittent or peak setting as a screen, then calculate RMS current and winding temperature over the full motion profile before selecting a motor. IEC 60034-1 duty labels such as S1 and S3 are useful only when the supplier states the actual cyclic duration factor.
It can be better when the machine can provide bearings, alignment, and conductive cooling. It is not automatically better for simple bolt-on servo replacement.
Request torque-speed curves, continuous rating conditions, peak torque duration, winding resistance, inductance, Kv or Kt, rotor inertia, encoder options, drive voltage, mounting temperature, and mechanical drawing.
No. Public compact servo data can show high headline power while continuous stall torque remains below the torque needed at a particular speed. For 1 hp at 1800 rpm, compare against about 3.96 Nm before thermal derating.
A universal 1 horsepower flat servo motor package, universal cooling derate, and universal peak-duration limit are not supported by reliable public data. Those values must come from supplier curves and application tests.
OpenSpec classifies the phrase as an alias of flat BLDC motor. Keeping one canonical URL reduces duplicate-page risk while still answering the alias explicitly.
No. It is a deterministic first-pass screen. Production selection still needs supplier curves, thermal testing, servo tuning, mechanical verification, and application-specific safety review.
Related engineering paths
These internal paths keep the sizing workflow connected to selection, RFQ preparation, product architecture, and custom engineering decisions.
Use this after the calculator to define continuous torque, speed, voltage, thermal path, and mechanical envelope before RFQ.
Convert the 1 hp flat servo screen into supplier-ready OD, ID, duty, cooling, encoder, drive, quantity, and timeline requirements.
Compare flat BLDC and frameless torque motor options when the 1 hp target needs a custom heat path or direct-drive package.
Review the engineering path for winding, voltage, stack length, feedback, and mechanical interface changes.
RFQ next step
Include the calculator result plus voltage, encoder, quantity, mounting heat path, cable exit, and target production timing.
Inquiry Email
Include target torque/speed, quantity, and delivery location.