What should a custom BLDC motor RFQ include?
A useful RFQ includes the application, voltage range, continuous and peak torque, speed range, duty cycle, mechanical drawing, controller and feedback, environment, validation tests, sample quantity, forecast, and required schedule.
A message that says “quote a high-torque 72V motor” does not define a product. Suppliers still have to guess the loaded speed, duration of peak torque, shaft and mount, controller current, cooling, water and dust exposure, validation, sample plan, and commercial volume.
FCDC and FCDC Motor use this checklist to turn an OEM/ODM idea into a comparable engineering and purchasing package. It also helps buyers discover when a currently stocked platform can meet the job with less change. Availability, engineering scope, tests, price, and timing are confirmed only after the RFQ is reviewed.
Custom BLDC motor RFQ data table
Attach evidence wherever possible: drawings, route data, load profiles, photos, controller files, and measurable acceptance limits.
| RFQ block | Required inputs | Why it changes the design or quote |
|---|---|---|
| Application and duty | Vehicle or machine, mass/payload, terrain or load curve, run/rest cycle, ambient, service life. | Defines continuous thermal demand, peak events, shocks, contamination, and validation cycle. |
| Torque and speed | Continuous/peak torque, peak duration, minimum/base/maximum loaded RPM, acceleration, grade. | Selects electromagnetic platform, winding, gearing zone, cooling, and controller limits. |
| Electrical system | Nominal/minimum/maximum voltage, battery/BMS, battery and phase current, controller, charger, DC-DC. | Controls insulation, winding, connectors, current density, speed margin, and protection. |
| Mechanical interface | Envelope, mount, pilot, bolt pattern, shaft, key/spline, sprocket/pulley, rotation, cable exit. | Determines whether a stocked platform fits or a new housing, shaft, bracket, or tooling is needed. |
| Feedback and control | Hall, encoder, resolver or sensorless; temperature sensor; throttle, CAN, PWM or analog commands. | Must match controller hardware, firmware, low-speed behavior, diagnostics, and harness. |
| Environment and compliance | IP target and test method, mud/water/dust, vibration/shock, salt, altitude, temperature, market standards. | Affects sealing, materials, bearings, coatings, connectors, documentation, and lab plan. |
| Commercial program | Sample quantity, pilot quantity, annual forecast, target start, Incoterm, destination, revision ownership. | Separates one-off prototyping from a controllable production program and logistics quote. |
Describe the application and operating cycle
Name the vehicle or machine, its purpose, total mass and payload, tire or driven load, terrain, maximum grade, acceleration target, route length, run and rest periods, ambient range, altitude, contamination, and expected service life. Supply measured route or load data when available.
For replacements, include the original motor nameplate, part number, model year, failure mode, mating parts, controller, battery, wiring diagram, and dimensioned photos. KAYO, Honda, Yamaha, KTM, go-kart, and racing references must be tied to the exact variant; they are not universal fitment specifications.
Define a complete torque-speed requirement
Provide continuous torque and the thermal conditions behind it, peak torque and allowed duration, repeat rate, minimum controllable speed, normal operating band, base speed, maximum loaded speed, direction, and braking or regeneration needs. State values at the motor shaft or at the wheel and give the gear ratio.
If only vehicle targets are known, send vehicle mass, payload, tire diameter, grade, acceleration, top speed, rolling assumptions, and drivetrain efficiency so the shaft requirement can be calculated and reviewed.
Freeze mechanical and electrical interfaces
Attach 2D drawings and, where possible, neutral CAD. Dimension the mount face, pilot, bolt circle, shaft, key or spline, sprocket or pulley location, axial and radial load, allowable runout, cable exit, connector clearance, cooling path, weight limit, and service access.
List nominal, minimum, and maximum charged voltage; battery and phase-current limits; controller make and revision; Hall, encoder, resolver, or sensorless requirements; temperature sensor; command interface; CAN protocol; brake and direction logic; fuse, contactor, and pre-charge architecture.
Write measurable environmental and validation targets
Replace “waterproof” with an IP target and agreed test method. Define temperature range, thermal-cycle profile, vibration axes and levels, mechanical shock, mud, dust, salt, chemicals, wash-down, corrosion exposure, noise, and insulation tests that apply to the real installation.
List pass/fail criteria for torque-speed, efficiency or energy use, current, temperature, overspeed, stall or blocked-rotor protection, ingress, vibration, endurance, connector retention, braking, fault handling, and post-test inspection. Identify which party validates the motor, controller, battery, harness, and complete vehicle.
Separate sample, pilot, and production decisions
State prototype quantity, pilot quantity, expected annual volume, target production start, destination, trade term, packaging, spare-parts plan, documentation, labeling, and change-control owner. Ask the quotation to separate standard parts, engineering, tooling, samples, validation, unit price, packaging, and logistics assumptions.
A sound program freezes an approved drawing and parameter revision after sample testing, builds a controlled pilot, compares pilot data with the approved sample, and releases bulk production only when open issues have owners and acceptance evidence.
Files to attach to the first email
- One-page requirement summary with application, targets, quantities, destination, and contact owner.
- Dimensioned PDF plus STEP or another neutral CAD format when available.
- Torque-speed or vehicle-duty worksheet and controller/battery specifications.
- Pinout, harness drawing, connector part numbers, and communication protocol notes.
- Validation matrix with test condition, measurement, pass/fail limit, and responsible party.
FAQ
Can FCDC Motor start from an existing motor sample?
A sample can support inspection, but a controlled RFQ still needs drawings, interfaces, performance targets, operating cycle, controller data, tests, and ownership of the reference design.
What is the minimum order quantity for a custom BLDC motor?
There is no universal MOQ; it depends on platform reuse, engineering, tooling, materials, validation, and program economics, so FCDC Motor confirms it after scope review.
How long does custom motor development take?
Timing depends on requirement completeness, platform fit, tooling, component availability, sample iterations, tests, and approvals; request a milestone plan after the specification is reviewed.
Can a stocked motor be customized?
Often a current platform can accept controlled changes such as shaft, mount, winding, cable, connector, sensor, or controller setup, but feasibility and validation must be confirmed.