chainsaw process book

ProcessawChain

Chen Lu & Yi LiuSDES-502 Prof. John Schaffeld 02/15/2012 - 03/11/2012

To design a chainsaw in ergonomic and safety perspectiveResearch&Analysis

Conception

Usability Test

Final design

02/15/2012- 02/23/2012

02/24/2012- 02/29/2012

03/01/2012- 03/06/2012

03/07/2012- 03/11/2012 And process book

Research

How to use a chainsaw?

Professional user

Home user{

Professional user

FellingFelling is the process of downing individual trees, an element of the task of logging.

limbing An extension or projecting part of a tree. When the tree is lying on the ground, branches may be storing enormous potential energy through mechanical strain. When a branch is cut, often with a chain saw, this energy can be re-leased suddenly and the branch can jump dangerously. In addition, a branch may be support-ing the tree, and the tree can fall or roll when the branch is cut. For these reasons, delimbing is a skilled operation requiring careful safety planning.

BuckingBucking means cutting felled trees into short logs.

Home user

Cutting branches and woods

Safety

Kick back

White fingersMuscle presure

Safe cuttingCarpal tunnel syndromeHearing DamageRespiratory problem{

Kickback may occur when the moving saw chain near the upper quadrant of the bar nose contacts a solid object or is pinched.

Kick back

Long period using with chain-saw may cause crucial presure on elbow and front arms area. The presure will cause serious medical issues very badly.

Muscle presure

Vibration White Finger (VWF) is a Repetitive Stressful Injury also known as Hand-Arm Vibra-tion Syndrome (HAVS). The injury results from the continuous use of vibrating hand machinery for prolonged periods without sufficient breaks.

White fingers

Keep your body out of the path of a potential kickback. When making any vertical (bucking) cut, keep your body to the left of the guide bar, out of the plane of chain rotation.

Safe cutting

Carpal Tunnel Syndrome (CTS) is an entrap-ment median neuropathy, causing paresthesia, pain, numbness, and other symptoms in the dis-tribution of the median nerve due to its compres-sion at the wrist in the carpal tunnel.

Carpal tunnel syndrome

The chainsaw noise can cause hearing prob-lem or even deafness. Power tools can cause hearing damage after only 30 seconds.

Hearing Damage

The toxic gas and dust from chainsaw may cause Respiratory problem

Respiratory problem

Existing products

Other brands{

Analysis

We asked a lot of people try to hold the old chainsaw for a while until they can not stand the weight. Most of them can only hold the chainsaw for about 2 - 3 minutes. Chainsaw is heavy. They all feel crucial presure, espe-cially from their left forearm muscle.

Muscle presure analysisBiggest pressure goes to bicep and extensor carpi radialis longus of left arm. Since continuly squeezing rear handle with right hand, the hand muscle will sour.

We measured main di-mensions of existing chain-saw to help us design our own chainsaw. Handle is the focual point of our observation. We also learned how a chainsaw is combined with different parts.

The elements of chainsaw

Conception

Evaluation 1Develop feasiable ideas from sketches

Usability Test

Mock UpsUse foam to build previous designs for usability test

We built two main bodies and four handles to find out the best combination.

A1 A2 A3 A4

B1 B2 B3 B4

Evaluation 2Ask different people try our new designed chainsaw mock ups

TESTERS USED IT BEFORE? BEST CHOICE COMMENTS

A4

A1

B1

A4

A4

A1

A4

A1

A1

B1

If I can hold both upper and lower parts of handle 1, it would be better.

Traditional one feels better.Handle 2 is really bad, I can not use it.

The movable part is not stable for power tool like chainsaw.

If I can hold three sides of handle 4, it would be better.

Handle 4 gives me a lot of flexibility.

Movable parts cost too much to produce.

I love A4 a lot. I hate handle 2, it disturb me a lot when I try to use it.

There are reasons for original chainsaw to be like that.

I like traditional one.Handle 2 is bad.

The traditional handle allows users to cut in straight way natually.Hanlde 4 can be used by home users not professional users.I can use handle 1 to cut in low position without blocks.

Based on this result, we decided to develop A1 as our final design.

Final design

Rotatable handle can fit with both professional users and home users.Change the handle to an angle to cut in low position without any blocks. Cutting logs straightly with straight position-handle as tradition way.

How towork with a chainsawhttp://www.jackssmallengines.com/pdf/chainsaw_cons.pdfChainsaws at workhttp://www.hse.gov.uk/pubns/indg317.pdfTophandled chainsawshttp://www.hse.gov.uk/pubns/afag308.pdfBasic chainsaw felling and manual takedownhttp://www.hse.gov.uk/pubns/afag302.pdfTree workhttp://www.hse.gov.uk/pubns/indg278.pdfChainsaw felling of large treeshttp://www.hse.gov.uk/pubns/afag307.pdfChain Saw Safetyhttp://www.uscupstate.edu/uploadedFiles/About_upstate/Planning_and_Organizational_Development/Training/Chain%20Saw%20Safety.pdfChain Saw Safety Manualhttp://www.stihl.co.nz/p/media/download/uk-en/STIHL_Chain_Saw_Safety_Manual.pdfHow to Operate Chain Saws Safelyhttp://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cts=1331520388821&ved=0CEQQFjAA&url=http%3A%2F%2Fwww.flagsafe.ufl.edu%2Fpowerpoint%2Fchainsaw%2520safety%25203.ppt&ei=gmNdT9LsPJCatwfiy5CADw&usg=AFQjCNHgQXx1Et8CfqezTPSWu5DaZlbONgChain Saw Injury Statisticshttp://www.elvex.com/facts08.htmChain Saw Safetyhttp://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=18&cts=1331520660575&ved=0CGwQFjAHOAo&url=http%3A%2F%2Fwisha-training.lni.wa.gov%2Ftraining%2Fpresentations%2FChainsawSafety.pps&ei=jGRdT-rfBc_qtgfu7_mGDA&usg=AFQjCNGkw7dSk1Mt365yffzvX0xpOYTWWASites:http://en.wikipedia.org/wiki/Chainsawhttp://www.stihl.com/http://www.husqvarna.com/us/products/chainsaws/husqvarna-chainsaws-for-homeowners/http://www.hse.gov.uk/treework/safety-topics/chainsaw-operator.htmhttp://www.youtube.com/results?search_query=chainsaw&oq=chainsaw&aq=f&aqi=g10&aql=&gs_sm=3&gs_upl=147l693l0l841l6l6l0l1l1l1l228l530l3.1.1l5l0http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=chainsaw&x=0&y=0

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Chen Lu & Yi LiuSDES-502 Prof. John Schaffeld 02/15/2012 - 03/11/2012