Designing a pruning saw for professional use — Hultafors collaboration

Course: Ergonomic design, 6 credits, Umeå Institution of Design

This my explanation of a four week long course in ergonomic design that I did during november 2016. The main purpose of creating this article is to practice writing about cases and later use the material for my very first portfolio making. Though it’s always nice to interact with other people, so if you want to comment something, please do.

Mission: design a manual operated pruning saw for professional use according to Hultafors brand identity

1. Project background

1.1 Project aims
The aims of the four week long course was to get a good practical understanding of the design process, to emphasize the importance of how to integrate knowledge about ergonomics, skills and methods related to the design process. The project would also give insights on how to combine the need for a new product in relation to a brand, in this case Hultafors.

1.2 Design request
In the current situation Hultafors recently launched some hand saws for carpenter and wanted to expand their audience to professional users of pruning saws, such as arborists and landscapers. But they also wanted the tool to appeal to a audience interested in outdoor recreation and other quality minded people just in need of a durable tool to relay on. Beside desirable functions as providing great ergonomics, fitting into Hultafors product range and reflecting the brands core values, they requested a proposal for a foldable and manual one-hand operated saw with sustainability considerations.

2. Process

2.1 Brand research
Divided in teams by four we started to dig into Hultafors core values, target group, competitor analysis, brand design language and we also created a function list. I was in charge of studying the brand design language of Hultafors. However the teamwork were short and the project continued with individual work which covered deeper research in all of the mentioned fields. Before starting the brand research we already gained background knowledge about general ergonomics and tool ergonomics through lessons, articles and litterateur.

Hultafors core values:
TRUST; being reliable in every way 
INSIGHT; serving genuine need 
RESPECT; respecting people and the planet 
ACTION; impact is everything

I studied several tools from Hultafors existing collection, how they featured their products, tried to get a good picture of their brand identity, their future goals and also looked how other competitive brands developed. Maybe Hultafors needed to get inspired by competitors to maintain values like great innovations and functions.

From my research of Hultafors existing tool collection I made a chart trying to explain the main shapes that contributes to their brands design language.
Except from the main shapes, details and logotype, Hultafors have three main signature colors: Hultafors Black, Hultafors Red and Hultafors Metalic Grey.

2.2 Competitor analysis
To get a understanding of the work environment for the requested target group we brought a bunch of several competitors saws to the nearby Forrest. We worked in teams and took notes on our experience using the saws. I was surprised how a manual pocket saw could work so efficiently, but even as a unexperienced user I found some pros and cons with the existing pruning saws, which I brought in consideration to my sketch development.

As a beginner in forestry pruning I was surprised how a manual pocket saw could work so efficently. Though my unexperience I found some pros and cons with the existing prunings saws.

I found that a blade with big and slightly outwardly bent teeth was the most efficient cutter. Even if the teeth cleaned itself you sometimes had to rinse the blade with your hands. To reach branches ergonomically I found a longer blade preferred. The saws without great breaks in the front of the handle felt unsafe. If the handle neither had a great breaks in the end of the handle it felt slippery. Bacho’s Laplander felt like a natural extension of the arm, this because of the angles of the teeth are in line with your arm while gripping the handle. The unfolding of the blade could cause danger in many cases, specially if the user is new to the tool.

2.3 Sketch development
To let myself be able to idea freely but not get lost in the sketch process I constantly reminded myself about the necessary core functions Hultafors expected to see. The tool needed to provide the best possible performance, safety and precision. A tools that can handle tough applications, last for a long time and feel right in the hand.

“A tool to rely on” — Hultafors core value quote

To the sketching table I aslo brought some desirable function I believed could solve the problems I found during research and user testing, and of course offer Hultafors a tool to rely on.

  • Give the feeling of a natural extension of the arm
  • Guards in the front and back of handle
  • Enable folding and unfolding with only one hand
  • Enable folding and unfolding with both right and left hand
  • Have big and slightly bent teeth all the way down the blade
  • Have optimized blade length: long enough for deep strokes, short enough to be portable
  • Provide a adjustable angles of the blade
  • Be adaptable to a telescope handle
  • Be true to Hultafors form language: durable and reliable impression, geometric details, showing direction and movement, signature colors, special grip pattern, oval and black handle, show logotype

2.4 model making and user testing
Early in the sketching process I made a simple sketch model in polyurethane foam, this because I wanted to experience the length and grip radius before working on further details.

Tring my first sketch modell with students. I made the blade removable so I could lace rubber bands through both the front and the back of the handle so the user could try the sketch model with a more authentic resistance.
“The saw feels reliable just by grabbing it” — user during prototype testing

Already in the beginning of the model making I got positive feedback that the handle felt good in the hand and provided a good grip both in the front, middle and back of handle. On the typical oval radius that Hultafors have for their handles I added a extra layer on the back, this for making it more ergonomic for the palm and reduce risk of chock injury’s after long usage. The extra layer contributed to a comfortable feeling of the grip and fitted well for a natural finger placement. The users said at it also worked as a indicator for the grip. The guards that stops your hand from sliding of the handle or sliding over the blade were highly estimated by every user. Some users said that the saw felt reliable just by grabbing it. These exaggerated parts are also needful to fit the saw in a oval telescope handle, which was one of my desirable functions.

The exaggerated parts are also needful to fit the saw in a oval telescope handle, which was one of my desirable functions.

I took the feedback to the sketch table and did a new model with a hard core of polyurethane foam and a coating of clay, this because I wanted to give a feeling of the estimated weight of a real product. For the second user testing we were about to meet professional pruners who works for the municipality of Umeå. I fought that the professionals experience could be good to use for deciding the placement of a button, so my second sketch model and first clay model were made with a flat front part of the handle with the purpose to give the professional pruners the possibility to put a thumbtack where they preferred to have the button.

Picture of the final sketch renderings. The second sketch model were made with a flat front part of the handle with the purpose to give the professional pruners the possibility to put a thumbtack where they preferred to have the button..

The meeting with the professionals gave me great feedback I brought in to the refinement of my model. The grip radius could remain the same so the model only needed to be slightly shorter, thinner in the waist and to have the tip design tailored to the preferred button placement and at the same time have in mind that it should easily be able to slide down in a case or a pocket. When I decided the final shape of the whole handle I did the final changes on the blade shape, because I wanted the blade to have angles taken from the handle shape to give harmony to the fully impression of the tool. I also made shore that the blade angle in relation to the preferred grip angle still provided the feeling of a natural extension of the arm.

Sketches for the final pruning saw proposal, made with ballpoint pen and markers.

The third and final sketch model were created from the second model, which is the pros with working with clay. Because so few refinements were needed on the grip I focused on shaping the tip.

Getting the Hultafors signature grip pattern in place before coloring.

Although I wasn’t familiar working with clay and that I spent many frustrating hour struggling to master it, this modelling technique of reusing material from a previous model was my plan from the beginning and the this modelling solution may be great to bring to future projects.

Final pruning saw proposal

3.1 User scenario

Photos of the final model that visualize the user scenario
The button is placed so when pressing it you naturally remove the fingers from the space where the blade is going to release or close.

When you grip the saw while folded you have a comfortable grip because the shape of the blade allows you to fit your hand around the handle without the blade cutting into your hand. At the same time the blade has a exposed part which enables you to grip it if the blade would get stuck. The button is placed so when pressing it you naturally remove the fingers from the space where the blade going to release. If you push the button once a spring releases the blade to 120°C, so you’re able to manage the saw with only one hand. If you push down the button and press the blade towards a branch or other resistance you can adjust the blade to five different angels. When the blade get in to one of the five positions it tells you with a clicking sound. When you release the button the blade gets fixed and you are ready to get working. The two most extreme positions fix the blade in 45° and 270° which allows two different power grip. When you unfold and fold the blade the brushes in the scheats orifice rinses the blade to avoid moister and rust.

3.2 Color notation

The color placements is carefully made due to Hultafors values of simple, professional and brand iconic products

The color range is Hultafors Black, Hultafors Red, Hultafors Grey Metallic and the white Hultafors logotype so it stand out on the grey blade. The color placements is carefully made due to Hultafors values of simple, professional and brand iconic products. Just as all other Hultafors tools the grip is black and have the striped signature grip pattern. The blade is grey metallic to express quality and the handle have some red parts to be visible in dull environments and the placement gives balance to the product. The button is grey so the original color will last many years after wear and tear.

4. What I’ve learned

This project were my first experience of designing a product with a orientation to fit into a existing product range and adjust to pretty specific design demands. It was fun to communicate with designers from a big company and to get introduced to the arborist profession. But I found it hard to design a product with a ergonomically main purpose and pretty limiting brand design restriction, and still be happy about the aesthetics. I still think that I managed to present great ergonomic functions and at the same time have respect to Hultafors own design language. I’m also happy that my design answered all my desirable functions. To figure out the most efficient way of working were also hard, maybe I lost unnecessary much time while working with clay, maybe I should have showed more different models in the user testing, done more documentation and recorded a movie of the process and final results. If I had more time working with his project I also wanted to continuing developing the belt case and the telescope handle. Overall though this project developed my skills in ergonomic theories, doing research as finding brand DNA and do user testing, prototyping in different materials and showing the work through presentations.