Why teams engage PTL for bespoke motor design
Bespoke electric motor programmes usually begin when an off-the-shelf product cannot meet the full application requirement.
The key constraint may be performance, but it is often wider than that. Common challenges include thermal behaviour under load, restricted packaging, unusual duty cycles, controller mismatch, harsh environmental exposure, ingress protection, reliability, cost, quality or integration with a wider drivetrain or mechanism.
PTL is typically engaged when the motor cannot be treated as a standalone component. We carry out custom electric motor projects from concept, specification and feasibility studies through electromagnetic, thermal and mechanical design, architecture definition, prototyping, testing and development.
Our experience covers permanent magnet, induction and reluctance motors in radial, axial, in-wheel and linear motor architectures, as well as solenoids, actuators and bespoke motor-driven systems in demanding thermal, mechanical and environmental conditions.
Concept to Prototype for the eBike Market
We worked very closely with PTL in developing and licensing CVT drive concepts for the eBike market.
PTL were an outstanding partner – Applying advanced simulation techniques, developing innovative concepts and control software, and realising hardware prototypes. They were a responsive, reliable, and agreeable partner who I would thoroughly recommend.
CEO, eBike Systems Ltd
When to speak to PTL
Speak to PTL when you need to:
Feasibility, specification and route selection
Many bespoke motor programmes start before the requirement is fully defined.
A client may know the required outcome, but not yet know the most appropriate motor topology, cooling method, control approach, packaging arrangement or validation path. In these cases, the specification itself becomes part of the engineering work.
PTL can support or even execute this early stage through structured feasibility studies and concept-definition work. This may include reviewing the application requirement, identifying fixed and flexible constraints, comparing design routes, assessing technical risk and clarifying what should be proven before committing to prototypes.
A good feasibility study accelerates the programme. It reduces the risk of committing to the wrong route too early.
The scope is shaped around the programme, but the discipline is consistent: identify the main technical risks before the cost of change becomes too high.
Motor design in the context of the wider system
Electric motors sometimes fail to meet their specification because of system-level issues rather than electromagnetic design alone.
PTL’s background in powertrain and engine development gives the team strong capability in drivetrain integration, torsional vibration, NVH, mechanical behaviour and control-related issues. Integrating e-machines with engines, transmissions and other drivetrain assemblies is familiar territory.
This capability also applies outside automotive applications. Where a motor is being integrated into a wider mechanism, PTL can analyse the surrounding system as well as the machine itself. This helps ensure that the motor, controller, mechanical interfaces, cooling system and operating duty are considered together rather than treated as separate work packages.
This matters because many engineering issues arise at the interfaces: between components, control systems, companies, departments, operating environments, physical constraints or people.
Individually tailored projects
PTL can take bespoke electric motor programmes from early feasibility through to detailed design, building prototypes, testing them, resolving issues and preparing technical evidence for IPR, safety or commercial review.
The scope of the project is shaped around the application. Some clients need early concept review and feasibility work. Others require detailed electromagnetic, thermal and mechanical design, test planning, prototyping or practical problem solving on an existing design.
Feasibility, specification and design review
In the early stages, a Work Package can include capturing the requirement, reviewing designs, comparing topologies and using structured risk assessment using methods such as Pugh Matrix evaluation, FMEA, 8D problem solving and design for manufacture review.
This stage helps define what the motor needs to achieve, what constraints are fixed, where the technical risks sit and which design route is most appropriate before prototype cost increases.
Electromagnetic, thermal and mechanical motor design
PTL has extensive experience in the electromagnetic, thermal and mechanical design of brushless permanent magnet, induction, switched reluctance and other motor topologies.
Design work can include model-based engineering, Motor-CAD, 2D and 3D FEA and CFD, supported by thermal and mechanical analysis and simulation to assess whether performance and reliability will be acceptable under real operating conditions.
Specialist applications and harsh environmental
PTL has experience supporting motor design for demanding environments including subsea, downhole, pressurised, aerospace, wet- or acid-airgap and extreme temperature applications.
Where required, this can include ingress protection and hazardous-area considerations, including IP systems up to and including EExd, EExe and ExnA.
Cooling and thermal management
The reliability of motors is often limited by thermal degradation from being operated at the extremes of the envelope rather than by the continuously rated performance.
PTL can select and design a cooling strategy from the full range of options such as natural or forced ventilation, water cooling, oil-spray or oil-bath cooling, heat exchangers or other thermal management methods.
The objective is to ensure that the selected cooling is appropriate for the duty cycle, packaging and operating environment.
Integrated motor-driven systems
PTL can simulate or design the complete electric drivetrain where the motor forms part of the wider system. This may include the engine, motor, drive, inverter, controller, battery, cooling system and mechanical interfaces.
This is particularly important where system behaviour, controller matching, torsional vibration, NVH, packaging or mechanical integration create risk beyond the motor itself.
Prototype, test and validation
PTL can carry out design, build and test activity for electric motors and related devices. This may include preparation of the specification, topology selection, full design, tolerancing, drawing sets and DVP test programmes.
Work Packages can also include build-to-print prototyping, preparation of drawing sets from CAD, creation of CAD models from motor design data, manufacture of test rigs and execution of tests.
Production support, issue resolution and technical evidence
PTL can handle small production runs of motors and assemblies, including battery packs, where this forms part of the wider development route.
We also carry out practical problem solving where programmes encounter issues with design, integration, reliability, performance, manufacturing, cost, quality or safety.
Where required, PTL can prepare evidence for forensic investigations, technology assessments, IPR reviews and patent applications.
Why PTL is different
Proven motor and solenoid experience
PTL has experience in the design, prototyping and testing of most motor and solenoid types.
This includes work across Formula 1, BEV, REEV, aerospace, military and industrial applications, supported by wider powertrain and specialist application experience.
PTL also has experience with the patent application processes in the UK, EU, US and China, where technical evidence and clear engineering explanations are required to support the application.
Independent recommendations
PTL is independently owned and is not tied to a parent group with its own motor products, inverter range or manufacturing capability.
This means that topology recommendations are shaped by the needs of the application rather than by an in-house product preference or a route that PTL benefits from selling.
This is important for clients as it means that the engineering route can be selected on the basis of performance, integration, manufacturability, operating environment and risk, rather than commercial alignment with a pre-existing product range.
NDA-first working and client-owned IP
PTL normally operates under either the client’s NDA or PTL’s two-way version.
Any IPR developed during the project normally stays with the client. This is particularly important for inventors, funded development teams, manufacturers and investors working on proprietary technology.
PTL can also carry out regular gateway reviews and close cooperation where the programme requires structured decision points, evidence packs or ongoing technical review.
Direct contact with the engineer responsible
PTL operates through personal contact. In many projects, the engineer responsible for the work is also the main point of communication with the client.
This helps reduce problems at handover and keeps technical decisions closer to the people carrying out the work. It also promotes faster clarification when requirements, assumptions or constraints need to be tested.
Coordination across specialist work packages
Some projects require more than electromagnetic or mechanical design.
Where needed, PTL can operate as project manager, coordinating partners involved in control software, electronics and other specialist work packages required to complete the programme.
This is valuable because of the way that the technical risks often sit at the interfaces between the motor, controller, electronics, cooling system, mechanical package or operating environment.
International client and supplier network
PTL is based in the UK and works with clients and suppliers across the UK, EU, USA and China.
This tried and tested network supports programmes where specialist supply, prototype manufacture, testing, patent applications or international collaboration are required.
Examples of motor design projects
Six-Phase Switched-Reluctance Motor for a Power-Generation Application
PTL developed a six-phase switched reluctance motor for a Power Station cooling fan.
This project included the complete design, build and test of the prototype motor, which ran at 25,000 Nm and 95 rpm.
Downhole Pump Motor
PTL developed a specialised motor that would be used in an oil well as a downhole pump. Predictably, it was long and thin, with a measurable twist along the length of the rotor when under load, and operating in some quite extreme conditions. The project included both designing it and building the first prototypes.
e-Motor Development for a Pressurised Helium Heat-Pump Environment
PTL supported e-motor development for a pressurised helium heat pump environment, where the motor formed part of a demanding mechanical and thermal system.
The programme required the motor design to be considered alongside pressure containment, cooling, drivetrain behaviour and operating reliability. This reflects the type of work where motor design, mechanical integration and harsh-environment performance need to be addressed together.
Endurance and Root-Cause Work on the House of Commons Window Actuator Programme
PTL developed a window opening actuator using a bought-in brushed motor. During endurance testing the coupling failed and investigation showed that the steel parts had been made from incorrectly marked bar of a lower grade than specified.
This type of work shows the value of combining practical test evidence with engineering analysis when performance or reliability problems need to be understood clearly.
Related PTL capability
Bespoke motor programmes often employ more than one of PTL’s capabilities.
For wider vehicle, drivetrain or off-highway applications, talk to PTL Mobility Systems.
For controller integration, embedded systems, actuation, dynamic behaviour or test-rig requirements, see PTL Precision Control Systems.
For broader engineering support from concept validation through design, analysis, prototype planning and procurement, see Overview of Services.
Frequently asked questions about bespoke electric motor design
What happens next
A technical discovery call gives both sides a clear starting point.
The first step is to understand the application, current situation and main technical concerns. This usually includes the required duty, packaging constraints, operating environment, known risks and any work already completed.
PTL will then help identify what should be validated first. That may be a feasibility study, topology comparison, thermal assessment, integration review, prototype test plan or broader design and development support.
Where the project is a good fit, PTL can outline a practical route forward with the right level of engineering evidence for the next project gateway.
Book your technical discovery call
PTL offers a technical discovery call where you’ll speak directly with experienced motor and multi-physics engineering specialists.
What we’ll cover:
Technical Director |
R&D, Analysis and Simulation
