Case study

Challenge

• The customer was updating a well established emergency services radio. The previous generation radio had experienced multiple issues with the vibration alert feature.
• They wanted to upgrade the vibration intensity and address reliability issues that had plagued the previous model. This meant finding a new supplier.
• The radio needed to withstand extreme temperatures, a profile of ‘active’ and ‘rough’ use, as well as penetrate a new generation of more protective fire fighting clothing.

Solution

• We were lucky enough to enter this project with a clear list of improvements required for the next generation radio.
• Our engineers uprated the motor windings, bearings and eccentric mass.
• We upgraded the motor shaft and added / enclosed the motor with a rubber suspension cover. This reduced audible noise from the motor and enabled it to withstand accelerated drop tests.
• We undertook a design for manufacture review with the customer’s manufacturing engineers. This resulted in a PCB backpack with gold plated connection springs to speed up assembly.

Results

• The new generation radio was released with a long list of improvements that had been requested by the worldwide emergency services user community.
• Firefighters were pleased with the new radio’s ability to penetrate protective clothing when the radio was secured to chest and hip belts.
• Police and security forces appreciated the new radio’s ability to withstand repeated drops and continue functioning.
• Our customer’s production line staff were able to assemble radio’s quicker because of our assembly optimised features.

STAGE 1

Designing for application

• Following a number of tests on a customer vibration analysis machine, we made changes to the motor’s windings and eccentric mass.
• We also uprated the shaft and designed a rubber suspension cover to withstand impacts.
• We worked with their manufacturing engineers to implement a spring / pad electrical connection method, to simplify end assembly.

STAGE 2

Testing and validation

• We designed a new Tungsten weight with raw materials sourced in compliance with necessary Dodd-Frank anti-conflict minerals regulations.
• On initial prototypes the vibration performance was great, but longevity suffered. We used our testing validation process to find a more suitable load point for the motor and adjust the windings accordingly.
• We built a customised accelerated drop test to validate the ruggedness of the new design.

STAGE 3

Mass production

• We replaced leads and connectors with a PCB back-pack carrying gold plated surface mounted springs.
• This reduced the radio assembly time by 20 seconds per radio.
• It also eliminated a common failure mode identified at the start of our design review – vibration fatigued wire joints.
• Our dedication to quality consistency, focus on improved performance and continued commitment to investing in advanced testing technology, means radios with our motors, continue to serve with strength.