Choosing a BLDC motor for a lawn mower involves more than matching voltage, power, and speed.
In a recent lawn mower project, the customer required a 36V 1600W BLDC motor with a rated speed of 3000 ± 300 rpm. While the performance requirements were clear, the key challenge was ensuring that the motor could fit the customer’s existing mechanical structure.
This required detailed confirmation of the shaft, spacer, keyway, tolerances, and mounting dimensions before the final prototype could be produced.
For a custom motor, performance determines whether it can work — mechanical details determine whether it can actually fit.
Customer Requirements for the Lawn Mower Motor
The project started with a clear set of electrical and performance requirements:
| Specification | Requirement |
| Application | Lawn Mower |
| Rated Voltage | 36V |
| Rated Output | 1600W |
| Rated Speed | 3000 ± 300 rpm |
| No-load Speed | 3800 ± 300 rpm |
| Rotation | CCW |
| Motor Type | BLDC Motor |
At first glance, these specifications may appear sufficient for motor selection. However, for a replacement or customized lawn mower motor, electrical performance is only part of the evaluation.
Why Mechanical Dimensions Matter in a Custom BLDC Motor
A motor can meet the required voltage, power, and speed specifications but still be unsuitable if its mechanical dimensions do not match the equipment.
For this lawn mower project, several mechanical details required careful confirmation:
- Shaft diameter and length
- Spacer dimensions
- Keyway design
- Mounting dimensions
- Dimensional tolerances
- Shaft material
- Fit with the existing blade adapter
Based on the customer’s mechanical requirements, the final design included a Ø20 mm shaft, a 37.20 ± 0.5 mm spacer, and a 25 mm effective keyway length.
These dimensions were defined specifically for this lawn mower project rather than being standard dimensions for all Ø100 BLDC motors.
From Initial Drawing to Final Engineering Confirmation
After the basic motor specifications were confirmed, the engineering drawing went through several rounds of review.
Details such as shaft dimensions, spacer length, dimensional tolerances, shaft material, and compatibility with the customer’s existing blade adapter were reviewed before prototype production.
Why Multiple Drawing Reviews?
Small dimensional differences can affect assembly and mechanical compatibility. Confirming these details at the drawing stage helps reduce the risk of discovering installation problems after the prototype has already been manufactured.
What Can Be Customized on a BLDC Motor?
This project focused mainly on the shaft and mechanical interface, but different applications may require different motor configurations. Depending on the equipment and operating conditions, BLDC motors can be customized in several areas.
Electrical Performance
Voltage · Power · Speed · Torque
Mechanical Design
Shaft Diameter · Shaft Length · Keyway · Mounting Interface
Electrical & Control
Wiring · Hall Sensors · Encoder · BLDC Controller
What Information Should You Provide for a Custom BLDC Motor?
If you are looking for a customized or replacement BLDC motor, providing the following information can help us evaluate your project more efficiently:
Application — What equipment will the motor be used in?
Voltage — Required operating voltage, such as 24V, 36V or 48V.
Power — Rated and peak power if available.
Speed — Required rated operating speed.
Torque — Rated or peak torque if known.
Dimensions — Motor size and available installation space.
Shaft — Diameter, length, keyway, thread or other special structure.
Operating Conditions — Continuous or intermittent duty, temperature, waterproof requirements, etc.
Replacing an Existing Motor?
You can send us the motor nameplate, product photos, engineering drawing, and installation dimensions. These details can help us evaluate whether an existing BLDC motor platform can be adapted to your equipment.
Need a Custom BLDC Motor for Your Application?
This lawn mower project shows why successful motor customization requires more than matching voltage, power, and speed. Mechanical dimensions, shaft design, tolerances, and equipment compatibility also need to be considered before prototype production.
If you are developing a lawn mower, garden equipment, or other machine requiring a custom BLDC motor, send us your motor specifications, drawings, or existing motor information for an initial evaluation.