ERGONOMICS PROJECT : GARDENA HANDSAW
UID : 2015 : 4 weeks
To design a user adaptable handsaw that is safe for casual users, ergonomic and efficient while demonstrating a premium feel.
Design an ergonomic product
The purpose of this project was to get a practical understanding of the industrial design process with a focus on user-centric ergonomics. Working in tandem with Gardena we were posed the design challenge of redesigning a fixed blade handsaw for home gardeners between ages 30-70. The target product was one that displays the best ergonomics, clear branding, and fits in with the Gardena product line DNA.
how is a handsaw used in a home garden setting?
Workshop testing
After seeing how others utilize a hand saw certain questions were raised. How does the ergonomics of the handsaw change when the height of the branch being trimmed is changed (higher vs lower)? How is the existing saw's ergonomics while performing an undercut? How efficient does the existing saw cut? Using the workshop I tested the various cut angles in addition to attempting the undercut technique with the existing Gardena as well as two other competing saw designs. I found that the angle of cutting is frequently changing and the saw is used in short bursts of activity. I also found that the current handle designs of hand saw force the user into some awkward body positioning when undercutting.
Field testing
In order to gain a better understanding how users actively use hand saws while preforming tree maintenance I participated in a field test with Umeå Kommun workers. This field test and further research reviled the importance of using an undercut while pruning a tree. An undercut is when you cut underneath the branch then cutting off the outer part of the branch. Once the weight of the branch is removed the user can safely finish with a cut that removes the branch at the trunk of the tree. By using this technique you ensure that the bark of the tree doesn't get stripped, damaging the tree. It also allows for better cut accuracy closer to the trunk giving the tree the best shot at healing over the branch wound and preventing rot.
Task analysis
Once I had an idea of what features represented a Gardena product a full analysis of how this product would be put to use by a passionate home gardener was needed. Starting from how the saw was stored to how it is used I analyzed how the workflow would look. Questions that arose during this analysis included: How can the blade be protected during storage and transport? Who will be primarily using this saw? What kind of environment is the saw usually being used in? and What is the proper technique to use when pruning trees around ones house and property?
Gardena Design DNA
In addition to analyzing the ergonomics of the existing hand saw, with the aid of classmates I conducted a brand form analysis. Through doing this I would ensure that the new hand saw fit within the line of products Gardena produces. There are distinct feature that are shared through out most Gardena products. The first and possibly the most noticeable is the color used and how these colors are balanced based on the use of the product. The aqua color is the defining color for the brand Gardena. This is used as the color on the body of the products. Anywhere the user grips the product is colored black. Orange is used to inform the user of an interactive aspect of the product. Two more form features that often appear in Gardena products are parallel lines and circles
Three main functions
After conducting research in the field and in the workshop I narrowed down exactly what functions that I felt were required from the newly designed Gardena saw. When starting to think about these functions, with the help from fellow classmates, I brainstormed on what the functions could be as well as some words that represented the form language that would guide me through the ideation and sketching process. The three main words that came up were: QUALITY, INTUITIVE, AND ENJOYMENT.
3 Cut Method
The saw should ergonomically allow the user to execute an undercut when pruning a tree. This undercut function should be designed into the product so that the action is effortless and intuitive.
Safety
The saw should provide the user with a sense of safety and security during use. It should also ensure the safety and health of the tree being trimmed with minimal effort from the user.
Strength Maximization
The saw should be adaptable to all ages and members of the family. While all ages need to be considered, when focusing on the ages 30- 70 the saw needs to maximize the amount of force needed to operate.
three Concepts to address these three functions
Concept 1 : Straight Handle
Drawing inspiration from traditional Japanese hand saws that also operate using a pulling motion, my first concept explores the ergonomics of a long straight handle. The grip in this concept was designed with the intention of aligning with the form language of quality and intuitive. The segmented black grip is angled so when viewed from the top and back it has a directionality indicating a pull motion. Through these ideation sketches I began explore to use of a "fish belly". The more curved design also aligned better with the form language of enjoyment.
Concept 2 : Hand Protection Handle
With the form language words enjoyment and quality. Within the form language of quality, safety became a highlighted term. This concept became centered around how a handsaw can communicate safety to the user. I achieved this through separating the hand completely from the saw blade. I also included more flowing curves to help illustrate enjoyment.
Concept 3 : Undercut Handle
The importance of having a saw that effectively and ergonomically allows the user to undercut led to the concept of a shifting blade that can be used as a traditional pull saw and then flip on itself and be used to undercut with minimal effort from the user. In this design I heavily explored the role of circles within the design language.
3D Model Making
After narrowing down my ideation process to three primary concepts I continued developing my designs by producing to scale foam models. By doing this I was able to see which aspects of each design were either beneficial of immediately apparent that they were unfeasible or in need of changes. I explored varying lengths in the straight handles and varying angles within the closed and open grips. One thing that was starting to become clear was not only the angle of the handle in relation to the hand but also the proximity of the hand to the saw blade. The closer the hand is too the saw blade the more efficient and accurate the saw seems to be, but it also leads to the anxiety of the user cutting their hand. After making these models I had plenty of questions going into the next phase of my design process, user testing.
User Testing
Going into user testing I had two primary questions that needed answering: Do users prefer a long, medium, or short handle? and What angle handle in relation to the saw blade do users prefer? I provided the users with sets of models for them to grab and feel without any resistance in order to get their initial reaction on how the handles sit in their hands. Once they had selected their top three handles I then conducted a pull test using a demo blade and a rubber band in order to simulate a pulling saw motion. I then got their feedback on which of their selected handles either improved or got worse with the resistance.
Findings
My two main questions were answered. Users preferred a shorter handle and one that had much more angle than a straight Japanese handsaw style. They also confirmed my suspicion that the closer the hand was to the saw blade the more in control and stable they felt while sawing. This became even more evident when the saw handle was used in a resistance test. I left the user test with a much better idea of what I wanted to address in my further refinement of my designs.
final design
Strength Maximization
After the user testing I had the goal of combining what I had learned from the ideation process, the feedback received, and the three main functions. I arrived at the angle of the handle by finding the middle ground between the two most popular handles from the user testing. I then took that angle and moved the hand as close to the saw blade as well as maintaining an alignment of the arm and saw blade. This made it possible to transfer the force needed directly to the blade efficiently. By moving the hand very close to the cutting teeth, aligning the whole arm with the saw blade, and placing the center of gravity just ahead of where the saw meets the handle allows for an efficient and accurate pull saw.
SAFETY
I decided to go with a rounded and flowing feel to the overall design of the handle. While the hand is placed relatively close to the cutting teeth of the saw blade, the risk of the user cutting their hand is mitigated by fully enclosing the hand with a protective guard. Combine this with a very friendly and inviting overall form the saw is designed in a way that welcomes the user to use it and it does not come across as overly technical. The saw is designed to guide the user in conducting the safest possible tree maintenance not only for the user, but for the tree as well.
Ergonomic undercut
One of my main three functions that I set out to achieve was how to design a handsaw that allows for the safe and proper use of the three cut method. Initially I thought of moving the blade to various positions rather than the arm. Then I thought of various ways to design the handle angle in order to have the whole saw rotated and flipped in order to facilitate an undercut. These solutions either were over designed or impractical solutions that disrupted the workflow. These solutions steered away from my form language of intuitive. Instead I chose to design the blade to have a curved saw teeth on the top of the saw. Having this design feature would allow the user to use the same arm positioning and require little in terms of readjusting. The curve not only fits in with the rest of the handle's rounded design but it also allows for more efficient cutting given the shorter surface area of cutting teeth.
HOW IT FITS gardena's design dna
While this hand saw is unique and specifically designed, it does align with the brand DNA of Gardena. It has a strong, but not overstated, influence from circular forms. The placement of the black grips aligns with where the user will be gripping and pulling on the saw, and the simplicity and elegance of the design gives it an overall premium feel. Overall this saw provides the user with an adaptable product that is safe for casual users, ergonomic and efficient while demonstrating a premium feel.