HANDLE CONCEPT
FOR STRING TRIMMER
To improve the user experience by focusing on ergonomics and cognitive aspects
BRIEF
The main aim of the project was to redesign the existing handle for string trimmer for the brand Cramer.
The model taken under consideration was a battery powered string trimmer for professionals with a bike handle model that usually works with two side carrying system.
One of the main aims of the project was to improve the comfort of handles / reduce the fatigue while being used; the other to improve the human machine interface effectively to provide better experience.
in collaboration with
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TO IMPROVE
After conducting user testing with the existing product, the main areas which found to be improved were
ERGONOMICS
+ Trigger, perfect spring tension
- Power button, reduce the activation pressure
- Unlock button, need full extension of thumb
- Reverse button, hard to reach
- Grip, both need to be more comfortable
SEMANTICS
- Speed button, hard to notice
FORM LANGUAGE
- Control panel, low quality
RESEARCH
How to improve comfort of the handles / reduce fatigue while using?
How to design the human machine interface effectively to provide better experience?
To find answers to these questions, different research methods were executed to find the exact need.
IDEATION
The ideation started with both sketching and clay modelling. Detailed quick digital renders were conducted to verify the semantic aspects of the concepts.
FORM EXPLORATIONS
To accomplish the best ergonomic handle - just sketching would not have guaranteed the intended outcome. To achieve the best output, clay mockups were made and 3D scanned the best to make the look like mockups for evaluation.
EVALUATION AND REFINEMENTS
Selected mockups were evaluated by industry experts to validate and list down pros and cons of each concept. Further refinements were made and tested with multiple rapid prototypes.
HANDLE CONCEPT
FOR STRING TRIMMER
FINAL DESIGN
An elegant design with emphasis on improving the user experience
by focusing on ergonomics and human factors. The design language of the handle needs to go along with the that of the existing body.
DISPLAY FEATURES
The messages in the display provide solid human machine interface
and give prompt feedback about the status of the machine thereby improving
the overall experience of using the product.
PHYSICAL ERGONOMICS
The handle form is optimal for long duration usage - which is a common scenario for grass trimmers. The Unlock trigger, the speed button, reverse button and the power button are placed in the range of thumb movement. All of these can be activated without loosing the power grip.
The shape of the top face of the handle is well crafted to accommodate easy movement of thumb and at the same time, the right side of the head has proper support for the hand to rest. The base form provides enough surface area to support the tapping motion to release the cutting cable from the spool.
COGNITIVE ERGONOMICS
While battery is connected, only the power button lights up to show what operation to conduct next.
The controls for activating the functions for proper functioning of the handle guarantee easy and clear visibility with lit up buttons. The lock and unlock toggle is in the range of thumb movement. When it unlocks it is clearly visible from protruding outwards, which restricts the movement of thumb.
DFMA
Internal components of the final design are almost the same except the circuit board with the display. This would provide for the company to implement new design with minimal cost difference.
