BACU

u n iB Z SUM M E R - S E ME S T E R - P RO J ECT 2 0 2 0 P L A NTI N G . T E N D I N G P I C K IN G

BACU

Jo n at h a n Z wi e Ã&#x; l e r L u c a s G ei g e r P ro f. K la u s H a c k l R icc ard o B e r ro n e T izian a P i c c i o n i

planting. tending. picking

baculus, baculum: lat. shepherd‘s staff, the crutch

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planting. tending. picking

BACU

00_INTRO

01_RESEARCH / PROCESS

02_CONCEPT / IDEATING

10 The Billhook

22 Old hands vs New grips

12 The Secateur: A refined tool

24 The crutch meets the secateur

14 The mechanism

26 First sketches

16 The handle

30 First Prototype

18 The science of gripping

32 Ergo-Social 34 Modularity: Crutch as principle 36 Experimentation

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03_REALIZITION

04_BACU: A VISION?

44 First Concept Render 46 Second Concept Render 48 Fixing Mechanisms 50 Pruning Mechanism 52 Saving weigth & Surface pattern 54 Technical drawings 56 Final Render 60 Manufacturing: 3d Printing 62 First 3D-printed Prototype 66 Real world application

planting. tending. picking

00 INTRO

When the 2020 summer-semester-project „planting.picking.tending.“ officially started Wednesday, March the 4th, nobody could imagine the unusual course the semester would take. It was a sunny morning, when the 17 students, lead by Professor Klaus Hackl and accompanied by Riccardo Berrone and Waldtraud Kofler visited the nursery Schullian. Under the shining sun, Mr. Hundbiss allowed us a glance into his precious collection. On the tables in the greenhouses, a variety of historic garden tools laid, from little shovels over knives to the heart of the catalog: dozens of old pruning sheers, meticulously crafted and engineered. At this point, the region Lombardi 200 km away already had over 2000 active cases of the new Corona-virus, short covid19. A day later, it was official: Uni is closed, the reopening date not clear. It should be the start to an unusual project.

The entirety of the following project was created through the digital platform TEAMS, an video communication software, with the participants and contributors some6

times being around 1500km away from each other.

What was planned originally as an Semester full of personal and close teamwork developed into a international experiment: would it be possible to design something for the outside, more precise, the garden, while not only being far away but being in strict indoor quarantine?

The „planting.picking.tending.“- Project from Professor Klaus Hackl takes the student through a journey, beginning from a deep and thorough historical research of garden tools over broad brainstorming to the final development of a unique solution. This did not change in the unexpected turn of the semester. For us, Jonathan and Lucas, it was no different: starting from an analysis of a pruning sheer with all its components, followed by interviews with winegrowers and garden technicians, slowly an idea began to grow. While the pruning sheer itself is a 200 year old tool, refined through the centuries, there still is a group of people having difficulties using it: Elderly people and the community of disabled.

Recognizing the back, bending down and the wrist as weak points of the movement in the garden, the first concept of bacu was born: a long pruner with a supporting element for the forearm and an additional handle.

Recognizing the advantages such an element could have on other tools than the pruning sheer, we deconstructed bacu to develop something bigger than a Secateur: a modular supporting system to help users in all areas of gardening. planting. tending. picking

01 RESEARCH PROCESS 8

planting. tending. picking

THE BILLHOOK And the connection with winegrowing In the beginning of the project the winegrower Martin Gojer, owning the „Weingut Pranzegg“ near Bolzano, gave us a quite useful insight in his work.

We learned about his biodynamic method to grow wine in south tyrol, his phylosophy towards wine and the difficulties in the future. But what we found most interesting for our project, was his attitude towards tools. As a winegrower, Martin said, he would just use one single tool most of the time: the sécateur. It is used all over the year from grapevine pruning in the winter to the final harvest in early autumn.

The precursor of this unreplaceable tool is the bill hook and many different sorts of pruning knifes. Even those are connected quite close to the history of winegrowing. The earliest finds are dated back to the iron age. Since then the billhook had more a hoeing and choping function, had a big blade from 20 to 30 cm and was named differently in every country: the billhook in 10

England, the Serpe in France, the Hippe in Germany, the Gertel in Switzerland. But the romans were the first who properly developed and initally spread the vine knife. In roman language the „falx vinatoria“, is a smaller version of a billhook, the blade has a length of 10 to 20 cm and the curved form allows an more drawing cut (01p.). This cut is more precise and suitable for pruning grapes than the brutal choping cut of the big billhook, which was mainly used to cut foliage or even branches.

In France a similar development took place and the smaller version of the Serpe became the Serpette. In the 19th century the sécateur replaced the billhook at least in winegrowing and general pruning and also hobby gardeners completely switched to the use of sécateurs. The italian brand „leonelli“ manufactures any form of billhook till today.

billhook choping cut planting. tending. picking

THE SECATEUR: A REFINED TOOL A historical tool...

The sécateur was invented by Antoine Francois Marquis Bertrand-Molleville. There were some reasons for the succes of the sécateur.

For beginners it was easy to work with, whereas the billhook could be dangerous if not properly used.

The most important advantage is the improvement of the precision of the cut. Concerning the billhooks the refinement from a pushing, to a drawing cut was already a valuable 12

improvement (01). But still the pruning movement was a quite rough one, which hurt the plant by unclean cuts. While cutting some specific foliage or little withered branches it was impossible to not cut also good foliage or blossoms. As a consequence plants always needed to recover these accidental cuts. The french sécateur solved these problems but still in Germany it took a while until it was proved and accepted.

01

Rebschere (02) simple closing with a loop and nib

Blades: Bypass pruners usually work exactly like a pair of scissors, with two blades „passing by“ each other to make the cut. At least one of the blades will be curved: a convex upper blade with either a concave or straight lower one. So the make a clean cut and don‘t squash the branch like anvil prunners do.

Closure: There are many different closing mechanisms to prevent the sécateur from reopening when not in use. Simple mechanisms often just have a small loop and a nib at the end of the handle (02). More complex systems have the closure directly at the blades to block them with a small metal wedge (03).

the felco classic (03) most known sécateur in europe planting. tending. picking

MECHANISM Different spring types Talking about the mechanism of a sĂŠcateur we mostly talk about the reopening mechanism, also called spring.The first sĂŠcateur models used two opposing leafsprings (01).

Parallely also just one leaf spring was introduced. In more modern times Most often in secateurs a volute spring is used, as for example in the most felco secateurs. A volute spring is a compression spring in the form of a cone (05). Under compression, the coils slide past each other, thus enabling the spring to be compressed to a very short length in comparison with what would be possible with a more conventional helical spring (04). Whereas japanese secateurs often have a long helicalspring with just one winding. That is a more stable option than the normal helical spring and a quite simple, elegant solution, alternative to the volute spring.

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01

02

03

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05 development of springs 01 double leaf spring 02 one leaf spring 03 special bent leaf spring 04 spiral spring 05 volute spring (used by felco) planting. tending. picking

THE HANDLE The initial excursion into the field of ergonomics The variation of handles especially is especiallly regarding sécateurs quite interesting, because in comparison to other tools the way to use a sécateur or a shear is quite clear and doesn‘t give so much space for interpretation.

But the optimal interaction of spring and handle is key here. As one can see in 01, the closed form of the handle guides the hand and prevents you from losing the sécateur while reopening after closing. The spring can also be integrated more directly into the handle, so that it almost disappears while closing (02). Most often the handles are the extended and new formed part of each blade.

Therefore they are also made out of metal. Sometimes also turned wood is sticked on top (02) to give it a better ergonomic feeling. Another modern way to make the handle more comfortable and prevent it from slipping, is to add gum as one may know of the red felco classic (04).

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01

02

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04 types of handles 01 added grip ring 02 spring included in wood grip 03 metal grip with slip-to-blade protection 04 ergonomic gum grip (felco) planting. tending. picking

THE SCIENCE OF GRIPPING The process behind every handle

While researching about the sĂŠcateur‘s handles we got more and more interested in this final connection between tool and user. We realized that if you want to understand the form of a handle you have to understand the way you grip it. It is an interaction: in the way your hands grips the handle, it finally defines how the whole tool is gonna be used.

The point is that our hands grip tools how they were educated to use them.

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When you forget about this and start analyzing a handle and the tool just in its pure form you suddenly discover a complete new potential of what this tool can be used for. Or wether this grip could feel better if added to another tool. You start to play with new ways of using a handle by combining classic tools with each other, without inventing it totally new.

What does the finger do? it replaces a kind of spring, to open the crimp or a shear again

It is important to understand where the hand or the fingers touch the handle. At these points there is a given potential to add force. But what other effects can you have on a tool if you just change the finger or the position of the hand. How can you reopen a scissor/crimp after closing? You put your little finger on the outside of the handle, so that the

nail can push against one handle to reopen it. A scissor has ring forms at the ends of the handle to create this little „counter pressure“ much faster. The sĂŠcateur you hold more like a crimp in order to use the force of the whole hand while closing. But the spring enables you to reopen again without changing the positon of your fingers.

Our research went on exploring these simple and important relations. planting. tending. picking

02 CONCEPT 20

planting. tending. picking

OLD HANDS VS. NEW GRIPS The problem of two hand tools

While blades and the springmechanism went through drastic evolutions, the form of the handle kept the classic form for the longest time.

The reason is probably that the main customers of gardening products have a good basic fitness and to them other properties are more important than having a strange formed handle. High material quality, multifunctionality and the match with a kind of vibe are more influential factors for the buying decision than the own health.

So for healthy people this is quite comprehensible but what is with the group of people who have an inability or physical restrictions because of their age?

According the ergonomics student Gulia Wurster the „gardening career“ of old people often ends with the day when they can’t use both hands simultaneously anymore.

Because one hand is needed to lean on something most of the gardening tools are impossible to use because you are not able to create the same power as you can with two hands. In our modern society, primarily older people have the time to work in the garden. Rehabilitation approaches use gardening even as a form of therapy, allowing the patients to find to inner calmness outside 22

in open air. But while many gardeners are of older age, only few tools cater to the specific demands of older hands and users. This lack of support for a whole generation of gardeners seemed like a unique opportunity to design something that initiates change.

planting. tending. picking

CRUTCH MEETS SECATEUR A millenial old walking support reimagined.

We wanted to design a pruning sheer and recognized walking around and bending down as the weak points and problems gardeners are facing, especially older or disabled people. If the gardener cant get to the plant (without bending), why not get the tool to the plant?

Meaning: a long Pruning sheer with a trigger-like pulley-system to enable the blades and cut the plant.

A good idea at first sight. But after closer inspiection, the first doubts surfaced. On the one hand, there was already competition: Other manufacturers already offerd similar prducts. On the second hand, there was a component, none of these manufacturers payed attention to: the wrist and limited strenght of older people. While a long pruner may enable pruning without bending down, it disregards the the difficulties of users with stability-problems, weak wrists or shaking hands.

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The following idea was unusual at the beginning: Taking an existing product, a crutch and fixing it at the end of a pruning sheer. The crutch, a object made for leaning on and supporting the whole body while walking and the secateur, a delicate, small and precise tool seemed at first glance like an unlikely couple. With with every step further, the more confident we became: We had the possibilty to completly change the way the gardener interacts with a tool and the plant.

planting. tending. picking

FIRST SKETCHES

Working without bending down.

An extended reach for the gardener, allowing him to work the protecting back while also moving the weight from the blades and branch from the wrist to the forearm, acting as counterpressure 26

planting. tending. picking

FIRST SKETCHES

Leaning on a pruning sheer?

Weight distribution of a gardener with stability problems onto his crutch-pruner combination 28

Crutchmodul and pruning mechanism

The counterpressure-principle: Front weight is being distributed to the back. planting. tending. picking

FIRST PROTOTYPE

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To test the movement and handling of the crutch element as well as the mechanisms of a longer pruning sheer, we build a first mock-up, combining an existing medical crutch with a old pruner. A string fixed to the handles of the Pruner lead through a ring to the hand, where attached to a stick it could be pulled to close the blade.

One important realization of this prototype were the difficulties of transforming the pressing movement of a normal pruning sheer to the pulling movement of our idea. Different mechanical solution came to mind, including a pulley-system or a gear-translation.

planting. tending. picking

ERGO-SOCIAL DESIGN? Collaboration with Giulia: A glimpse into the ergotherapy bachelor

Information is one of the most important tools of a designer. Only after gathering all data possible, beginning from historical research to future studies, he can truly start to create.

If we wanted to approach the topic of assisting tools and supporting objects as well as aproach a target group of elderly people and disabled, we had to gather information.

Through the recommendation of a friend and student, we were able to collaborate with Giulia, a student of the ergotherapy bachelor of the Claudiana university in Bolzano.

Giulia Wurster told us that a great part of her work consists of building products for disabled persons.

She does so individually, every person has his own issues, problems, disabilities, they are always a bit different from one to another. Concerning the market she explained us that there are special products for certain dissabilities but 90% of them have at least one of the following problems: 32

a they are ergonomic and helpful BUT they look like clinical tools, they are not beautiful, what is for physical persons who are physically disabled but mentally fit often a reason not to use it. Of course not! b they are often super expensive: why should I buy an ugly tool, which also costs a lot? c one could argue that the problems are too diverse and you can‘t find a solution for every problem. Concerning that you should just look at the existing tool market!

There are solutions for problems, which are no problems.

Problems were created by designers just to sell their product/solution for it. But like our previous research shows, the real professionals are using a small number of products since decades. For a part of them it might be true that they are just not willing to change their habits, but for the majority it is more a question of sense. We think, that we as designers often lose this sense. We are creating products for super small target groups, trying to match their vibe and find a compromise between consumerism and our ethical values. But what is about these people, who cannot consume of this market? In our opinion designing for this existing, but completely unexplored market is a task we should more promote and demand more of our faculty. Maybe sociologists can connect designers at this point with fields where design really matters, where simple design can really make someones life better.

So called „easy-grip“ tools for people with weak or shaking hands. These ergo-therapeutic tools were an inspiration during our research.

planting. tending. picking

MODULARITY: CRUTCH AS PRINCIPLE Emerging from the secateur, the crutch extension can applied everywhere

While researching and experimenting with the topic of the crutch, we quickly came to the realization that the counter-pressure principle could have real potential on a variety of tools, not only the pruning sheer. To allow the user to have one arm free (for balancing or holding a crutch) while the wrist of the other hand is relieved of the weight seemed like a helpful addition to rake, shovel or broom. The idea of a modular approach came to mind: To create an object applicable to every area older people might need support.

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First visualization A physical collage of a shovel and the back of a crutch. This being unusual and confusing at first, the concept of shifting force away from the wrist to the forearm seemed worth the exploration, since the hope was to relieve the hands from the weight of the load carried by the shovel and make it easier to navigate the tool due to the stabilization of the armrest.

Expert interview: While Jonathan talked with a winegrower, Lucas turned to his local tree nursery. While the staff there was heavily relying on good pruning sheers, the main tool of their small business was the shovel and spade.

They use it to move plants, dig in new ones, cut roots etc. We realized, that our concept of a handle system could be applied at a much broader scale than previously thought, starting from the pruner to shovels, rakes and more planting. tending. picking

EXPERIMENTATION First real world tests with the ergotherapy advice from Giulia in mind

precision

300g 36

weight

This is a comparison of two different principles how to hold a stick under a relatively heavy weight to see how this affects joints, power and back position. In general this practical comparison of two different handholds proved what we were already thinking before: holding/picking up something with a normal handhold on a stick is not very efficient, because you lose power at the wrist joint (01). as consequence you can just hold shorter sticks or you have to reduce the weight. Stabilizing the wrist with a kind of splint you can create a counter pressure and transfer your power better (02). Disadvantage is that the wrist is used in an unhealthy angle. The solution for this is the pistol grip. Another „natural“ way to stabilize the wrist is using the index finger as a kind of mini splint for the hand (03).

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03 planting. tending. picking

EXPERIMENTATION First real world tests with the ergotherapy advice from Giulia in mind precision

distance between handle weight 38

01

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By drawing circles under certain conditions on a paper you can analyze and visually see how precise you can act with these „disabilities“ 01 500g added near the handle 02 500g added in the middle 03 500g added near the top

03 planting. tending. picking

EXPERIMENTATION First real world tests with the ergotherapy advice from Giulia in mind

distance between handle weight

pressure on top 40

01

using a silicone pistol as handle made it possible to understand the ergonomics of our final handle and to understand how the lever principle feels in reality: the longer handle works as lever and without the natural counter pressure of the lever the tip would just sink down bottom comes up and the heavy workload come on the wrist as a consequence the wrist twists in an unhealthy position.

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03 planting. tending. picking

03 REALIZATION 42

planting. tending. picking

FIRST CONCEPT RENDER The result of experimenting and sketching, virtually realized in CAD

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The first 3d-Images after weeks of researching and experimenting are exiting. The own concepts and ideas realized in an understandable and professional way. For the designer, this step is crucial. First of all, it gives him confidence, seeing that his work resulted n something, that at least virtually is possible to create. On the other hand, it gives the designer another look at his design, allowing him to spot missed details or questionable decisions.

The first render showed us, that our modular concept makes sense and could work. But it also showed us that there are to many components.

For a target group of older people, the appearance itself was already to complicated: We had to approach the topic in a more minimalistic way.

The bottom render show a first glanze at our idea of a systematic adaptation of bacu to a range of other tools, taking only the supporting elements without the pruning principle. planting. tending. picking

SECOND CONCEPT RENDER Improved and more modular approach

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After revisiting the modular concept with the discoveries of the last render in mind, it was clear we had to make the whole structure more minimalistic and more realistic to manufacture. Furthermore the material question was not answered, since using wood as the main component did not seem like a particular good idea anymore, considering weight, manufacturability and “outdoor-proofness�.

In the next step, as shown in the render, we agreed on a common system, a ring clamping onto a wooden stick, on which the handle and the armrest would be screwed on or welded. The idea was that with these rings, any type of tool could be slid through and attached, eg. a rake or shovel.

planting. tending. picking

FIXING MECHANISM How to get an object fixed to a stick?

Bendable rings The previous presented rings were the first method to tighten the grip as well as the armrest to the wooden sticks. We believed it to be a very realistic approach since similar objects already exist and can be found ready for purchased. The disadvantage is the amount of components needed to assemble the structure.

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Screw technique The next logical step was to simplify the structure, reducing the amount of components needed. An aluminum block would slide over the stick, being tightened only by a screw.

Prof. Hackl reminded us that there are different sticks from different tools, having a handle or a thicker end which would prohibit this from sliding on top.

Final mechanism: A clamp To be applicable to different thicknesses of sticks or stick-ends, we finally decided to go with a two-component solution, having the upper part interacting with the arm, and a counterpart, pressing the object to the stick

planting. tending. picking

PRUNING MECHANISM The heart of the secateur: Blades and spring

Spring to open up the blade after closing it. This in one of the key features in the pruning mechanism, because it allows you to continuously work with the tool without having to change something, like opening the 50

handles manually. This positioning of the spring has some disadvantages, since it is exposed to the branches and/or dirt the blades come in contact with, therefore being endangered of malfunction.

THE BLADES are the only part of the pruner, which comes in contact with the plant. To be opened and closed, force has to be applied. The amount of force drastically changes regarding to how is gets transferred. The so called lever-principle dictates the ratio between the length of way the leaver has to be pulled and the amount of force, that is needed. In our case, the biggest force on the blade exists when the red lever is angled at 90 degrees (Image 2). Therefore the blades are in a position where the most force is needed, exactly when they enter the branch or plant. planting. tending. picking

SAVING WEIGHT: SURFACE PATTERN Make the structure lighter, enhance the grip and ensure a modern look

Changing the construction After we decided on a formfactor and a fixing mechanism, it was obvious that the structure itself was solid, so far to dense and heavy. It was also not looking aesthetically pleasing or appealing. In order to give the handle and armrest a new, modern look and save weight, we introduced a layer-based construction.

This went hand in hand with the decision to print the objects in 3D (see „Manufcturing“). On the right, the result can be seen.

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Inspiration The idea to change the grip-structure from a solid to a layer-based construct is actually inspired by the handle of a snow-avalanche-shovel. It ensures a good grip and is saving material and weight at the same time

3D-designing To keep the workload small and have a constistent result when changing from solid to a layer-structure, the original handle design was analised using contour lines, which then were cut and extruded resulting in the different surface layers.

Combining Vertical planes were introduced to make the structure stable, and connect it to the main part resting on the stick

planting. tending. picking

TECHNICAL DRAWINGS HANDLE

40 mm

53 mm

50 mm

66 mm

130 mm

22 mm

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ARMREST

120 mm

120 mm

22 mm 60 mm 80 mm

planting. tending. picking

FINAL RENDER

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After summarizing all discovery’s we made by sketching, rendering and discussing with Riccardo Berrone and Klaus Hackl, it was time to revisit the CAD-Program a last time to combine details and changes we wanted to make. The result is a clean, dynamic shape with a modern pattern and a neutral, calming color.

On the left side, an interpretation of bacu used on various tools can be seen, also with a new idea: to use more than one grip to allow for the second hand to help.

planting. tending. picking

FINAL RENDER

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planting. tending. picking

MANUFACTURING: 3D PRINTING Once a futuristic vision, now wideley available

When we started researching about a long pruning sheer for elderly gardeners, we wanted to create a distinct contrast to common medical tools found on the market, which have a boring, clinical look, so the fist impulse was to work with wood. Later we considered aluminum or silicon-molding plastic, but we soon figured out than being stuck home in quarantine, there was only one realistic technique to create the complicated shapes we had in mind: 3D-Printing.

3D-Printig seemed like a technology from the future for a long time, but now is commonly available and has many advantages.

The first being the ease-of-use: We already had access to a printer in Germany, so all we had to do was to prepare the files in a 3D-Software (in our case „Rhinoceros“ ) and save them in an Stereolythografical file (STL). In another application (CURA) we have further options, choosing the density of the filament or the layer-thickness. The printer does the rest, no previous knowledge required. The 3D-printer then takes a roll of commercially available PLA-Filament, the most common used plastic for printing and heats it up to a temperature of 60

over 200 Degrees , melting it. The so called extruder of the 3D-printer, a nozzle moved by motors is driving over the bed of the printer, is spreading the liquid plastic in the shape determined by the 3D-File, essentially “painting” the structure. The filament hardens immediately when coming into contact with the previous layer, resulting in a very hard, but still lightweight structure.

3D-Printing also comes with some disadvantages.

The resulting object is super hard, rather breaking before bending. It also is quite time-consuming. Lucas 3D-Printer, a commerically available one, took over 24 hours to print all 4 pieces, 11h for the armrest, 8h for the handle and another 5h for the bottom fixating counter-elements.

While Lucas printer could not print the more complicated pattern in the handle, the “fablab”-Workshop in Bolzano could.

30% Density: At the bottom of the picture you can see the grid-like filling of the structures, here building the first layers for the armrest. The cube with the warning label contains the hot extruder, which is moved over the so called printing bed. planting. tending. picking

FIRST 3D-PRINTED PROTOTYPE From the digital file to the physical object

The objects are printed with a 0.2 mm layer height, which results in a medium fast printing process.

The inner filling of the structure is filled with 30% density, and the core is empty to safe material and weight.

What doesn‘t sounds like much is actually a rock hard and very stable result.

At the bottom, where the elliptic hole is placed for the stick, you can see the helping structures. They are needed by the printer as support to build upon and are removed later

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PLA filament is the most common material used when 3D-Printing. In this case, over 30m of the 1.7mm thick filament-string where used to create the upper part of the grip alone, taking about 8 hours to finish. In the next step, helping structures the printer uses as framework have to be removed. planting. tending. picking

FIRST 3D-PRINTED PROTOTYPE From the digital file to the physical object

The finished prototype: The 4 individual pieces are connected using metric screws and nuts. In the final prototype we plan to use wing nuts as shown in the renders to ensure quick tightening and allow for an easy change between different tools. The holes at the stick are elliptical to create pressure on different stick thickness.

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Drilling screw-holes Even though the holes for the screws where included in the 3d-file, the printer fills them with helping structures.

Grinding and milling To create enough space for the screw heads and to allow for a smooth handling, final touches are applied, including milling with the DREMEL, a electric multi-tool with small drills. planting. tending. picking

REAL WORLD APPLICATION From the computer to the garden: The final step

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From virtual to the garden After hundreds of hours worth of video-conferencing, digital revisions with Professor Hackl and a swimming pool worth of coffee, we finally had a working, physical prototype.

What was for the longest part only an idea existing on paper or 3d-programs could now be tested outdoors.

Using only one hand One of the main advantages of bacu can now be seen in real-life : The possibility to have one hand free for leaning on a crutch. This makes it possible to work without having to miss the support especially elderly people are dependend on planting. tending. picking

REAL WORLD APPLICATION

Counterpressure-Principle With the prototype working we could prove that the counter-pressure principle was actually functioning the way it was planned to. Lifting a broom, rake or shovel was possible with out the slightest movement of the wrist and with on hand only. All pressure and weight was applied to the elbow. For tools with a heavy metal head (shovel, iron-rake) it has to be mentioned that it was hard to lift everything with on hand only, but in this case a second front handle could be installed, making using of a second hand possible

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Bacu on multiple tools As designed, the two-element fixing mechanism makes a fast changing between tools possible, and allows it to apply bacu to various sticks of all thicknesses. Since it can be taken apart, it is no problem if there are handles or hanging mechanisms at the end of the stick already. Here bacu can be seen on rakes and a broom. It has to be mentioned that a pushing movement ( e.g. with a broom) is more intuitive with bacu than a pulling movement (rake). planting. tending. picking

FINAL PROTOTYPE

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fablab produced prototype color „ultimate green“ 1,5 days printing duration Cost 25€ planting. tending. picking

BACU: A VISION? A concluding text on the concept of bacu.

Interviewing garden „veterans“, professional winegrowers and landscape gardeners one thing became pretty clear: they all have one or two favorite tools, which they are using to do almost everything in the garden. For my grandma it is the hoe, for the winegrower Martin Gojer it is the secateur and for the landscape gardener Andrea Fellner it is the spade. They appreciate these products in their simplicity that in the same time makes the product multi functional, durable and essential for their work.

In their eyes every attempt to improve a product like this will mostly just complicate it. And if you finally decide to buy an improved tool, there is a universe of products developed for nearly every specific task that you can imagine. In history one of the earliest „explosions“ of forms was the billhook. It is fascinating in which diversity human beings developed forms and ideas to tackle a specific task. There were blades for a rough chopping function, for a fine drawing, to lance something and hundreds more. But what became obvious that mainly the billhooks blade form was improved, whereas the handle stayed in a quite rough form.

Of course also the handle was developed further, it was made longer, shorter, turnery allowed to shape first ergonomic forms, diverse functions were added. Nevertheless this almost insane intensity of shaping was more seen at the development of blades. This had different reasons: one was that doing an extra effort just to make the han72

dle more comfortable seemed ridiculous in these early days, whereas the changing of the blade form was quite practical, because you could add directly another obvious function. Another reason is that the rougher the form of the handle the better you can change hand positions and vary in the way you use the tool. It is not defined and determined where to grip. This fact is quite important till today and for the development of our project.

Coming from billhooks to secateurs we could notice a similar phenomenon. Secateurs replaced the billhook in many fields, firstly in rose pruning and wine growing.

This ingenious idea to combine two blades and make them work reversely (of course first invented with the normal scissor) makes it possible to make a clean, precise cut, without having any experience in cutting.

Concerning secateurs the field of handles had been more improved.

One reason for that is that secateurs entered this field of hobby gardeners, more than billhooks which demanded a higher skill level from the gardener. Hobby gardeners hands are compared to a farmer quite sensitive so the handles were made a bit more ergonomic. But still the focus of inventors and developers was more set to the other parts of the secateur: the spring and the blades.

Now in the twenty-first century the market hardly changed: there are hundreds of different springs, there are ratchet mechanisms which allows a weak person to cut thick branches, there are blades for almost every

planting. tending. picking

plant. It is hard to find something that doesn’t already exist. However the field of handles is a way less explored. You find the same few forms over and over again. Roughly said there is the Felco form, which is imitated most often, then there is a closed curve form, added that the secateur doesn’t slip away and some other forms often just differing in materials.

The keyword „ergonomics“ hasn’t played such a big role so far.

The reason is probably that the main customers of gardening products have a good basic fitness and to them other properties are more important than having a strange formed handle. High material quality, multifunctionality and the match with a kind of vibe are more influential factors for the buying decision than the own health. So for healthy people this is quite comprehensible but what is with the group of people who have an inability or physical restrictions because of their age? According the ergonomics student Giulia Wurster the „gardening career“ of old people often ends with the day when they can’t use both hands simultaneously anymore. Because one hand is needed to lean on something most of the gardening tools are impossible to use because you are not able to create the same power as you can with two hands. At this point of our project we decided to pursue a two-track strategy. On the one hand we made this deep research about secateurs which finally led us to the idea to make a long secateur for old people which allows them cutting something without begging down. On the other we saw a great potential in the observation of Giulia, which refers only to „two hand objects“ though.

So the goal of our project was set: develop something 74

which transforms two-hand objects into one-hand objects. Discussing with Giulia and experimenting with different grips we finally came up to the grip of a crutch.

At first sight this may sound obvious because a crutch comes exactly out of this field of inability and old age, but the way we used the crutch grip is a completely uncommon one and also the core of our project. In our heads we had this first memory of using crutches as children, because we had a broken leg or a friend had one and we were keen on trying out this new „toy“.

Sometime we found out that it could be cool to hold the crutch like a futuristic kind of gun and we fought in an imagined war against aliens. This initial experience we remembered and we were curious about the real potential of a crutch, maybe not as a weapon though. Actually we started to play at this point like we did 10 years ago.

We experimented with weights hanging on a crutch or tried to draw with one. We changed the way we grip the handle and even applied it on our secateur idea.

We noted down everything that felt uncommon but interesting. After these experiments we recognized that in certain movements the crutch creates a counter pressure, which stabilizes the wrist enormously and increases the power of one arm with a sort of lever principle. We discussed our notes again with Giulia and she helped us recognizing what is important to consider in the further development. One point was the ability to change the length of the handle, which is normally not included in a crutch. So we divided the one piece grip into two pieces: the grip and the arm rest. Then we started to sketch how we could connect these pieces in a flexible way that allows you to adapt the length. Finally we simplified our complex ideas and used the shaft of the tool, on which the grip is applied, as bar and connection of the two

pieces. The next challenge was to find a suitable fixing mechanism for that. After some drafts the way we wanted to produce the object decided about this question.

For 3D printing there was just one of our ideas suitable in order to keep the whole thing stable: a kind of vice principle, where the shaft is jammed between the end of the grip or the back of the armrest and a counterpart.

Both parts are screwed together with a normal M6 screw and a wing nut.

Bacu is an experiment on different levels. Firstly it is a mini revolution to give the user of garden and household objects the chance to interact on a new, active way with the grip. Not only old people could benefit from this idea, also professional workers who often do one monotonous movement all day long could adapt the way to grip to the optimum and prevent postural deformities.

Secondly we believe that the collaboration with the ergonomic studies of Claudiana is quite valuable and would not only make sense but also be important to develop further in future projects. There is hardly another field where it is easier to pair playful, intense, pure creativity with science and historical based knowledge in order to really improve the life of people. It often means the world to them.

planting. tending. picking