Nerf gun

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*More obvious function
*More obvious function
*Short Range if not primed well
*Short Range if not primed well
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===USABILITY STUDY===
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User 1-  Male CMU Mechanical Engineering student
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Buzz Saw-
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user winds up the flywheel, releases 3 rounds
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“slow reaction, feels kinda laggy, anti-climatic”
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Rapid Fire AS-20-
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Ian: “you got to pump it 30 times”
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User: “well that’s annoying”
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user pumped it, fires entire clip
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“Okay that’s cool, that’s my favorite so far. This one is the best”
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starts loading
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“This process sucks”
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user suggestions: “replaceable clip”, “use some sort of power instead of pumping”
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User 2 – Female CMU student
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Big Bad Bow
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She resisted. Didn’t “find it fun to touch someone... [hurt someone]”
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User 3 – Female CMU student
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asked if it was fun to play with them
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we said yes
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she declined anyway
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User 4 – Female CMU student
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Ian: “you would very much like to play with Nerf guns right?”
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“I like that one; is that a cross bow”
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Big Bad Bow-
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user had some trouble figuring out how to use it, but eventually figured out how
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to retract the bow and fire it. After firing one shot, tried to fire again without reloading.
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“I thought it would spin and load itself” disappointment “... In a Nerf battle you don’t have time for that. ‘Kind of a let down”
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“Definitely have the aesthetics down. It looks cool”
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user attempts to fire another shot. It fired and then fell short about 2 feet from the user. User was not too surprised.
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User suggestions: “[I would like it more] if it was more interactive.  It looks like a very cool contraction but it’s just a glorified gun.
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Buzz Saw
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wound up two pulls it flopped 3 balls on in front of her.
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“oh God I think I broke it”
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“That’s it?!”
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“That’s really disappointing”
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Ian shows how to use it
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“That’s really annoying; I want it to stop making that noise”
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She winds it up, and shoots a few rounds
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“it’s much cooler now. Maybe it’s cuz of the wind.”
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“Oh it ran out of bullets already”
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User suggestions: “Maybe I would be excited using it if I was a 12 year old boy.”
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User 5  - Male CMU student
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Rapid Fire AS-20
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“The design is bad.  I don’t like the look.”
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User 6 – Male CMU Mechanical Engineering Professor, Professor Messner
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Rapid Fire AS-20
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Fires all the rounds
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“Oh this is way too cool”
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We retrieve the ammunition and load it
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“Let’s see I should recharge.”
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Starts pumping
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“It’s a pretty good workout”
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Finishes pumping
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“How many [rounds] does it have?”
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Ian: “20”
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Messner: “We’ll time it”
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Ian: “2.2 seconds”
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“10 rounds a second
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“600 rounds a minute”
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“Now you need a belt”
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User 7 – Male CMU student
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Big Bad Bow??
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“it shoots pretty far”
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User 8 –Late middle-age Male, son is an Industrial Design Major
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Big Bad Bow
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“Cross Bow Design”
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“Symetrical, left handed or right handed. My son is lefty”
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user cokes the gun
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“cocked”
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“accurate”
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“gotta load one.  It doesn’t automatically load... It would be better if it automatically loaded”
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“Sight is no good. It’s so distorted in the sight... I sight without a lens is better.  Line them up [with] a cross hair here and cross hair here” pointing to the front and back.
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overall opinion “Okay I like it”
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Buzz Saw:
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“I think I got the hang of it. You got to pull on it.  Shoots 3 shots.—oh coo!l”
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Overall:
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“I don’t like that they are weapons.” “Saw is a violent name”
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Which do you like the most?
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“I like them all for different reasons. [the Buzz Saw] you can pump and vary the speed.  This one you can pump up and vary the speed... I think a smaller child would have difficulty pulling it back. Whereas [the Big Bad Bow] is easy.
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Rapid Fire AS-20
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us: you need to pump it 30 times
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“I had a pellet gun that you could pump only two times. – 30 times”
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“unique feature = rapid fire”
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“As a toy for young people I don’t agree”
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“heavy. Not balanced well.  It gets difficult to pump at 25”
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“A little heavy for a 7 year old. doesn’t have any sights. It’s bulky.”
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Us: what do you think about ammunition? What do you think about it being slow and soft, non-injurious.
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“It’s a given that it didn’t hurt.”
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“I put it on single and it didn’t single fire.”
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Big Bad Bow
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“large, more fragile, easy to use, intuitive, easy to aim, technology is obvious, so they can learn something.
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user suggestions: “make it clear so they can learn something... learn the mechanisms”
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Us: “So what do you think of the ammunition? any improvements there?”
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The packaging says don’t modify the darts
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User: “I was thinking that already”
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“[The ammution on the Rapid Fire gun] are more bullet like... it has more of them...”
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User 9 – Male CMU Student, Recorded by Ian
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Rapid Fire AS-20
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Lost air pressure to quickly on single shot mode
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Hard to pump
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User didn’t like that it was so large
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User thought it could be smaller
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User 10 – Male CMU graduate Student of foreign origin
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Big Bad Bow
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User tried to work the sights, had trouble and then removed sun glasses.
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User still had difficultly getting the darts to go where desired voices concern by saying “aiming problem”
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User would fire one dart then go retrieve it, load it and fire it again. Did not notice the extra ammunition at first.
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“Looks like a cross bow”
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“Looks like something from outer space”
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“I would rather see a cross bow”
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“You can aim but [it only goes] 2 or 3 meters and then just falls.
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User 11 – Late middle age Male with British accent
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Big Bad Bow
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First time firing the bow the arrow fell right away off the gun.
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Second time it went several meters
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“Oh I just didn’t know how to operate it”
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“Oh my son would love this!”
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As picking up the ammo, “the trouble is picking up the ammo”
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Rapid Fire AS-20
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Fires a whole round
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“Oh He’d really like this!”
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... “[These types of guns] leak or the pump fails
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“lifespan of the toy is very short”
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Buzz Saw
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No comment
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User 12 – Female CMU student unfamiliar with Nerf guns
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Big Bad Bow?
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Us: “you want to fire a Nerf gun?”
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User: “Why?”
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“[you mean for me to] shot at someone?!”
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We explain that we wish for her to use it without instruction. It’s for a class.
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User: “Do I pump it?”
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User had never played with one before. We did not provide any assistance at first.
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“This thing is confusing... Oh, I got it”
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User attempts to fire
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“Wait, it doesn’t go anywhere... It doesn’t go anywhere!”
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“Oh I got to load it”
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Fires gun
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“This could come with better instructions.”
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“Freaking confusing”
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“you have to load it every single time”
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User 13 – Male
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Rapid Fire AS-20
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“More ammunition”
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“Aw the pressure is gone”
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“I expected it to pump like 5 times [not 30].” User had a pump-action rifle as a child and had to pump it only 5 times to prime.
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Buzz Saw
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“It’s easiest to get the balls stuck [out of the three guns]”
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“can’t shoot up”
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“[It’s] lame!”
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“[it] Needs a funnel on top”
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“Awesome and funny name”
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“I like the simple design”
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“It’s a cool concept, but the fact that it gets stuck when building momentum [ruins it].”
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Big Bad Bow
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The bow is the most appealing at first
=== Performance Studies ===
=== Performance Studies ===

Revision as of 16:21, 19 September 2009

Contents

Executive Summary

Product Study

Functionality

Video Link of all Nerf Blasters Firing at Once


Big Bad Bow

Image:NerfBBB.JPG

Big Bad Bow Video

Rapid Fire 20

Image:NerfRapid20.JPG

Rapid Fire 20 Video

Buzz Saw

Image:NerfBuzzSaw.JPG

Buzz Saw Video

User Study

Users were picked at random to use and comment on the Nerf blasters in a public setting in the middle of the Carnegie Mellon Campus. Observations of the users were made and comments were recorded. The following is a compilation of all the observations and comments made about each product during the study.

Big Bad Bow

General Feedback: People tended to initially think the gun was very appealing, but after using it were often disappointed in its performance.

User responses:

  • Sight was useful for lateral accuracy, not for vertical positioning
  • Large learning curve for an accurate shot
  • Not good compared to other nerf weapons
  • Ammo breaks easily
  • Shooting mechanism is complicated, many misfires trying to get ready
  • Operation is not immediately apparent, unclear on how to hold it
  • Short Range
  • Too big
  • Fulfills a classic "image"
  • Can't de-cock the mechanism
  • Not immediately apparent how to cock it
  • Confusing design, too much is cosmetic
Rapid Fire 20

General feedback: This weapon was praised as the most enjoyable to use, but there were frequent complaints people had about getting the gun ready to fire.

User responses:

  • Takes forever to pump and load
  • Good for crowds
  • Is the most fun: most people would want to buy this gun after playing with all three
  • Not very comfortable
  • No pressure gauge, when should pumping stop?
  • Pumping force is too great
  • Tube behind grip is annoying
  • Hard to aim, there is no sight
  • Pump feels flimsy
  • More satisfying to fire than other nerf blasters
  • More "feedback" feel when firing
  • Tedious to pick up all the fired ammo
  • "Single Fire" mode does not function properly (fires multiple darts still)
  • Wasn't apparent at first that it needed to be pumped to fire
  • Not all of the darts fire; some get stuck.
Buzz Saw

General feedback: People seemed to like the shooting mechanism for this gun, but generally it didn't seem as fun to play with.

User responses:

  • Very accurate
  • Jammed frequently, and the top ball often did not fall into the shooting mechanism from the loading station
  • Makes an annoying sound
  • Makes an awesome sound
  • Is difficult or impossible to shoot at an upwards angle
  • Difficult to remember to stop pumping before firing, making shots inaccurate
  • Limited by the user's strength
  • Seems the easiest to improve
  • More obvious function
  • Short Range if not primed well


USABILITY STUDY

User 1- Male CMU Mechanical Engineering student Buzz Saw- user winds up the flywheel, releases 3 rounds “slow reaction, feels kinda laggy, anti-climatic” Rapid Fire AS-20- Ian: “you got to pump it 30 times” User: “well that’s annoying” user pumped it, fires entire clip “Okay that’s cool, that’s my favorite so far. This one is the best” starts loading “This process sucks” user suggestions: “replaceable clip”, “use some sort of power instead of pumping”

User 2 – Female CMU student Big Bad Bow She resisted. Didn’t “find it fun to touch someone... [hurt someone]” User 3 – Female CMU student asked if it was fun to play with them we said yes she declined anyway User 4 – Female CMU student Ian: “you would very much like to play with Nerf guns right?” “I like that one; is that a cross bow” Big Bad Bow- user had some trouble figuring out how to use it, but eventually figured out how to retract the bow and fire it. After firing one shot, tried to fire again without reloading. “I thought it would spin and load itself” disappointment “... In a Nerf battle you don’t have time for that. ‘Kind of a let down” “Definitely have the aesthetics down. It looks cool” user attempts to fire another shot. It fired and then fell short about 2 feet from the user. User was not too surprised. User suggestions: “[I would like it more] if it was more interactive. It looks like a very cool contraction but it’s just a glorified gun.

Buzz Saw wound up two pulls it flopped 3 balls on in front of her. “oh God I think I broke it” “That’s it?!” “That’s really disappointing” Ian shows how to use it “That’s really annoying; I want it to stop making that noise” She winds it up, and shoots a few rounds “it’s much cooler now. Maybe it’s cuz of the wind.” “Oh it ran out of bullets already” User suggestions: “Maybe I would be excited using it if I was a 12 year old boy.”

User 5 - Male CMU student Rapid Fire AS-20 “The design is bad. I don’t like the look.”

User 6 – Male CMU Mechanical Engineering Professor, Professor Messner Rapid Fire AS-20 Fires all the rounds “Oh this is way too cool” We retrieve the ammunition and load it “Let’s see I should recharge.” Starts pumping “It’s a pretty good workout” Finishes pumping “How many [rounds] does it have?” Ian: “20” Messner: “We’ll time it” Ian: “2.2 seconds” “10 rounds a second “600 rounds a minute” “Now you need a belt”

User 7 – Male CMU student Big Bad Bow?? “it shoots pretty far”

User 8 –Late middle-age Male, son is an Industrial Design Major Big Bad Bow “Cross Bow Design” “Symetrical, left handed or right handed. My son is lefty” user cokes the gun “cocked” “accurate” “gotta load one. It doesn’t automatically load... It would be better if it automatically loaded” “Sight is no good. It’s so distorted in the sight... I sight without a lens is better. Line them up [with] a cross hair here and cross hair here” pointing to the front and back. overall opinion “Okay I like it”

Buzz Saw: “I think I got the hang of it. You got to pull on it. Shoots 3 shots.—oh coo!l”

Overall: “I don’t like that they are weapons.” “Saw is a violent name” Which do you like the most? “I like them all for different reasons. [the Buzz Saw] you can pump and vary the speed. This one you can pump up and vary the speed... I think a smaller child would have difficulty pulling it back. Whereas [the Big Bad Bow] is easy.

Rapid Fire AS-20 us: you need to pump it 30 times “I had a pellet gun that you could pump only two times. – 30 times” “unique feature = rapid fire” “As a toy for young people I don’t agree” “heavy. Not balanced well. It gets difficult to pump at 25” “A little heavy for a 7 year old. doesn’t have any sights. It’s bulky.” Us: what do you think about ammunition? What do you think about it being slow and soft, non-injurious. “It’s a given that it didn’t hurt.” “I put it on single and it didn’t single fire.” Big Bad Bow “large, more fragile, easy to use, intuitive, easy to aim, technology is obvious, so they can learn something. user suggestions: “make it clear so they can learn something... learn the mechanisms”

Us: “So what do you think of the ammunition? any improvements there?” The packaging says don’t modify the darts User: “I was thinking that already” “[The ammution on the Rapid Fire gun] are more bullet like... it has more of them...”

User 9 – Male CMU Student, Recorded by Ian Rapid Fire AS-20 Lost air pressure to quickly on single shot mode Hard to pump User didn’t like that it was so large User thought it could be smaller

User 10 – Male CMU graduate Student of foreign origin Big Bad Bow User tried to work the sights, had trouble and then removed sun glasses. User still had difficultly getting the darts to go where desired voices concern by saying “aiming problem” User would fire one dart then go retrieve it, load it and fire it again. Did not notice the extra ammunition at first. “Looks like a cross bow” “Looks like something from outer space” “I would rather see a cross bow” “You can aim but [it only goes] 2 or 3 meters and then just falls.

User 11 – Late middle age Male with British accent Big Bad Bow First time firing the bow the arrow fell right away off the gun. Second time it went several meters “Oh I just didn’t know how to operate it” “Oh my son would love this!” As picking up the ammo, “the trouble is picking up the ammo” Rapid Fire AS-20 Fires a whole round “Oh He’d really like this!” ... “[These types of guns] leak or the pump fails “lifespan of the toy is very short” Buzz Saw No comment

User 12 – Female CMU student unfamiliar with Nerf guns Big Bad Bow? Us: “you want to fire a Nerf gun?” User: “Why?” “[you mean for me to] shot at someone?!” We explain that we wish for her to use it without instruction. It’s for a class. User: “Do I pump it?” User had never played with one before. We did not provide any assistance at first. “This thing is confusing... Oh, I got it” User attempts to fire “Wait, it doesn’t go anywhere... It doesn’t go anywhere!” “Oh I got to load it” Fires gun “This could come with better instructions.” “Freaking confusing” “you have to load it every single time” User 13 – Male Rapid Fire AS-20 “More ammunition” “Aw the pressure is gone” “I expected it to pump like 5 times [not 30].” User had a pump-action rifle as a child and had to pump it only 5 times to prime.

Buzz Saw “It’s easiest to get the balls stuck [out of the three guns]” “can’t shoot up” “[It’s] lame!” “[it] Needs a funnel on top” “Awesome and funny name” “I like the simple design” “It’s a cool concept, but the fact that it gets stuck when building momentum [ruins it].” Big Bad Bow The bow is the most appealing at first

Performance Studies

In order to compare the different guns in terms of performance, we set up experiments to test how the three guns compared with respect to distance and accuracy.


Distance Study

Set Up: Guns were fired indoors from a horizontal orientation from 33.5" above the ground, and the position where the ammo first hit the ground was measured. The gun was held very steady when being shot so that no extra forward momentum was imparted on the projectile. Tests were performed indoors, so there was no wind or other disturbances.

Big Bad Bow: 19.0, 19.2, 18.10, 18.10, 17.10, 17.2, 19.0, 19.1, & 18.7 (Average 18' 7")

Rapid Fire 20: 18' - 22' Spread

Buzz Saw: 26.10, 29.4, 29.5, 30.1, 32.2, 32.9, 29.3, 30.4, & 31.4 (Average 30' 2")

Pictures

Image:NerfDistanceTestBBB.jpg Image:NerfDistanceTestBBB2.jpg

Videos

Buzz Saw

Rapid Fire 20

Accuracy Study

Set Up: 3 people without previous nerf gun experience were selected at random to participate in the study. Each person was instructed to stand 17' away from a target and fire with each separate nerf gun at the target. Pictures were taken in order to discern their accuracy. Then one of our group members, after practicing with all three guns, did the same accuracy test and the results were recorded as well. By testing both groups, we will be able to figure out how easy each gun is to aim for a beginner, and for somebody with more experience.

Videos

Buzz Saw Accuracy Test

Rapid Fire 20 Accuracy Test

Big Bad Bow Accuracy Test


Results!!!

Product Dissection

Mechanical Function

Bill of Materials

Big Bad Bow

Part No. Name Function Quantity Material Mass Manufacturing Process Picture
101 Bow Arm and Outer Cog Cosmetic 2 Plastic 56g Injection Molded
102 Small Inner Cog Cosmetic 2 Plastic 5g Injection Molded
201 Front Left Cover Priming Mechanism Housing 1 Plastic 117g Injection Molded
202 Front Right Cover Priming Mechanism Housing 1 Plastic 118g Injection Molded
203 Rear Right Cover Barrel/Action Housing 1 Plastic 123g Injection Molded
204 Front Left Cover Barrel/Action Housing 1 Plastic 119g Injection Molded
301 Nozzle Air Delivery/Dart Delivery 1 Plastic 17g Injection Molded
302 Nozzle Tip Air Restriction/FOD Protection 1 Plastic <1g Injection Molded
303 White Tip Holder Holds Nozzle Tip 1 Plastic 3g Injection Molded
304 White Air Restrictor + Spring Air Restriction 1 Plastic/Steel 3g Injection Molded
305 Rubber Piston Air Delivery 1 Latex Rubber 5g Injection Molded
306 Barrel Lock Action Lock 2 Plastic 2g Injection Molded
307 Piston Shaft Air Delivery 1 Plastic 26g Injection Molded
308 Trigger Lock Action Release 1 Plastic 2g Injection Molded
309 Trigger Action Release 1 Plastic 8g Injection Molded
310 Spring Stop Piston-Cylinder Spring Compression 1 Plastic 1g Injection Molded
311 Cylinder Air Delivery 1 Plastic 26g Injection Molded
401 Eyepiece Cosmetic 1 Plastic 4g Injection Molded
402 Eyepiece Lens Cosmetic/Aiming 1 Acrylic <1g Die Cut
501 Arrow Dart Ammo 3 Styrofoam 5g Molded/Glued
901 Screw Fastener 18 Steel 0.5g Forged/Machined
902 Spring for Barrel Lock Action Spring 2 Steel <.5g Rolled/Bent
903 Short Trigger Spring Release Mechanism 1 Steel <1g Rolled/Bent
904 Long Trigger Spring Release Mechanism 1 Steel <1g Rolled/Bent
905 Piston Spring Air Delivery 1 Steel 12g Rolled/Bent

Preliminary Analysis

Stakeholders

Some of the main stakeholders in nerf guns are the children who play with them, the parents who buy them and supervise their use, and the retailers that stock them.

Children: The children in this case are the end users, the one who actually use the product. They are also the ones who probably nag their parents into buying them, so it's both important that the guns appeal to them before they are bought, and they are enjoyable. In particular, children will enjoy a gun if it is "fun" to play with (generally involves power, ease of use, & physical appeal)

Parents: Even though the children play with the toy, the parents have a large stake in it as well. If the gun ever doesn't work, the parent will of course have to deal with returning the gun, or buying a replacement (or replacement ammo). Also, if a child is ever injured while playing with the toy, the parent has to help heal the injured child, and probably reprimand another child. Parents will like most the gun that is safe to use (very little chance of injury) and reliable (no need for extra trips to the toy store).

Retailer: The retailer has the smallest stake in terms of day to day use, but their profit off the item is what determines if it stays available to purchase. The retailer will only like items that are popular (sell quickly, attract attention), have no customer support issues (no returns), and are easy to keep in shop (not breakable, easily storeable).


DFMA

FMEA

DFE

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