Difference between revisions of "Power Scissors"

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(Analysis Of The Paper Feeder)
('''Scissor Jaws''')
 
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[http://gicl.cs.drexel.edu/wiki/Bucknell_Mechanical_Design Bucknell Mechanical Design Home]
 
<br><br>
 
 
=='''Power Scissors Dissection'''==
 
=='''Power Scissors Dissection'''==
  
[[Image:DVPrinter2.jpg|left|thumb|300px|Figure 1: HP Deskjet 600c Before Disassembly]]
+
 
[[Image:DVNoCase.jpg|left|thumb|300px|Figure 2: HP Deskjet 600c Without The Case]]
+
[[Image:overall1.jpg]]
  
 
== Function ==
 
== Function ==
The primary function of the Power Scissors is to cut through different materials.  There are two blades, the bottom one stays stationary, and the top blade moves rapidly, opening and closing.  This action allows the tool to cut through things.
+
The primary function of the Power Scissors is to cut through different materials.  There are two blades, the bottom one stays stationary, and the top blade moves rapidly, opening and closing.  This action allows the tool to cut through different materials.
  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2) Another stepper motor, undocks the printer carriage. The dock is used to secure the carriage, and to keep the printer head clean.
 
[[Image:DVDockingStation.jpg|left|thumb|300px|Figure 5: Docking Station For The Carriage]][[Image:DVWormGear.jpg|left|thumb|300px|Figure 6: Stepper Motor That Drives The Dock Using A Worm Gear]]
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3) The printer carriage is operated by a drive belt, which is powered by a third stepper motor.
 
[[Image:DVDriveBelt.jpg|left|thumb|300px|Figure 7: Belt Drive System]][[Image:DVBeltMotor.jpg|left|thumb|300px|Figure 8: Stepper Motor That Drives The Belt Using A Toothed Pulley]]
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
   
 
 
 
 
 
 
 
 
4) The printer cartridge applies ink onto the paper according to the instructions supplied by the CPU through the copper contacts.
 
[[Image:DVContacts.jpg|left|thumb|300px|Figure 9: Cartridge To CPU Interface]]
 
  
 
==Parts==
 
==Parts==
The table belows lists the components for the HP Deskjet 600c printer:
+
The table belows lists the components for the Black & Decker Power Scissors.
 
+
 
{| border="1" align="center"
 
{| border="1" align="center"
 
|+ '''Table 1: Power Scissors Component List'''
 
|+ '''Table 1: Power Scissors Component List'''
Line 110: Line 19:
 
| align="center"|Serves as Power Supply for blades
 
| align="center"|Serves as Power Supply for blades
 
| align="center"|
 
| align="center"|
| [[Image:DVTray.jpg |center|thumb|50px]]
+
| [[Image:motor.jpg |center|thumb|50px]]
 
|-
 
|-
 
! 2
 
! 2
Line 117: Line 26:
 
|align="center"|Protects internal components and holds them together
 
|align="center"|Protects internal components and holds them together
 
| align="center"|Plastic
 
| align="center"|Plastic
| align="center"|[[Image:DVHousing.JPG|center|thumb|50px]]
+
| align="center"|[[Image:complete_open.JPG|center|thumb|50px]]
 
|-
 
|-
 
! 3
 
! 3
Line 124: Line 33:
 
| align="center"|The bottom blade remains stationary, while the top blade moves continually up and down
 
| align="center"|The bottom blade remains stationary, while the top blade moves continually up and down
 
| align="center"|Steel  
 
| align="center"|Steel  
| [[Image:DVLargeStep.JPG |center|thumb|50px]]
+
| [[Image:jaws.JPG |center|thumb|50px]]
 
|-
 
|-
 
! 4
 
! 4
Line 131: Line 40:
 
| align="center"|Provide power to motor
 
| align="center"|Provide power to motor
 
| align="center"|Wrapped in cardboard
 
| align="center"|Wrapped in cardboard
| [[Image:DVDockMotor.JPG |center|thumb|50px]]
+
| [[Image:battery.JPG |center|thumb|50px]]
 
|-
 
|-
 
! 5
 
! 5
Line 138: Line 47:
 
| align="center"|This forces the bracket to move by translating rotation motion of the motor, to translational movement in the bracket.  The bracket then causes the upper blade to open and close
 
| align="center"|This forces the bracket to move by translating rotation motion of the motor, to translational movement in the bracket.  The bracket then causes the upper blade to open and close
 
| align="center"|Plastic
 
| align="center"|Plastic
| [[Image:DVRail.JPG |center|thumb|50px]]
+
| [[Image:yoke.JPG |center|thumb|50px]]
 
|-
 
|-
 
! 6
 
! 6
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| align="center"|Holds Casing Together
 
| align="center"|Holds Casing Together
 
| align="center"|Metal
 
| align="center"|Metal
| [[Image:DVGears.JPG|center|thumb|50px]]
+
| [[Image:screws.JPG|center|thumb|50px]]
 
|-
 
|-
 
! 7
 
! 7
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| align="center"|Ball and socket joint limits movement of jaws.  The socket is ovular so it allows some movement of the jaws.
 
| align="center"|Ball and socket joint limits movement of jaws.  The socket is ovular so it allows some movement of the jaws.
 
| align="center"|Plastic
 
| align="center"|Plastic
| [[Image:DVCPU.JPG |center|thumb|50px]]
+
| [[Image:blade_housing.JPG |center|thumb|50px]]
 
|-
 
|-
 
! 8
 
! 8
Line 161: Line 70:
 
Spring – metal
 
Spring – metal
 
Switch - metal
 
Switch - metal
 +
|}
  
 +
=='''Customer Requirements'''==
  
 +
*Blades are sharp enough to cut different materials (1)
 +
**Have a sharpening function
 +
**Changeable blades for different materials to cut
 +
*Easy to use (2)
 +
**Has a low weight
 +
**Has a small size
 +
**comfortable to hold
 +
**Wireless
 +
**Easily accessible buttom to start
 +
*Aestheically Pleasing (3)
 +
**More likely to be bought
 +
*Long battery life, chargeable (4)
 +
*Doesn’t break if dropped (5)
  
 +
=='''Engineering Specifications'''==
 +
*Material for jaws is sharper than the intended material to cut
 +
**Corresponds to blade sharpness (1)
 +
*Batteries last for 4 hours of continuous use
 +
**Corresponds to long battery life (4)
 +
*Force of scissors is greater than 5N 
 +
**Corresponds to ability to cut through material (1)
 +
*Weight is less than 5 lbs 
 +
**Corresponds to easy to use (2)
 +
*Scissors retain sharpness for 40 hours of use
 +
**Corresponds to blade sharpness (1)
 +
*Torque on motor is great
 +
**Corresponds to ability to cut through material (1)
 +
*External casing can withstand force from being dropped
 +
**Corresponds to long-lasting (5)
 +
*90% of people surveyed found the scissors pleasing
 +
**Corresponds to Aesthetically pleasing. (3)
  
 +
=='''Scissor Jaws by Laura Chernak'''==
  
 +
[[Image:scissors.jpg]]
  
 +
1. What decisions were made in the design of this component/module?
 +
** In making this component it was important to find a way to create jaws for cutting that moved rapidly.  It order to solve this problem the jaws were made so that only the top jaw moved, while the bottom remained stationary.
 +
2. What are the critical features and dimensions? (It may help to annotate the screenshot of the CAD rendering.)
 +
**  Critical features of this component are the dimensions that correspond to the shape of each jaw.  The angle of the blades could also be measured, as well as the thickness to the part.  The angle of the blade affects the sharpness of the tool, and the thickness affects the load that can be withstood.  Another important feature was the angle that the jaws could open to, an attribute that is important to ensure that the tool is safe.
 +
3. What kind of loading do we expect to be on the component?
 +
** Loading can be expected from the material trying to be cut.  The force of the cutting, and the resistance of the material to be cut will create stress on the component.
 +
4. What measures can we use to evaluate performance?
 +
** To evaluate the performance of the jaws they should be tested regularly for sharpness. It is important that the jaws retain sharpness so that the tool can perform its function to cut through material.  This can be tested by determining the forces necessary to cut through various materials.  It is likewise important that the jaw is functioning properly and not opening at too large of an angle, as this will deter from the safety of the tool.  This can be measured by determining the angle at which the jaws open.
  
 +
=='''Slider Mechanism by Victor Ceci'''==
 +
[[Image:sliderfront2.jpg]]
  
 +
1. What decisions were made in the design of this component/module?
 +
* It is clear that the decision was made to make the slider mechanism as simple as possible. Essentially it seeks to turn the rotating motion of the engine shaft into reciprocation motion perpendicular to the shaft with as little parts as possible, most likely to improve weight, cost, and packaging properties of the product.
 +
2. What are the critical features and dimensions? (It may help to annotate the screen shot of the CAD rendering.)
 +
* It is important that the slider is long enough to provide adequate clearance on either sides of its receivers. This ensures that as the slider moves back and forth between its holding brackets, that the receivers (which protrude from the slider), so no contact the brackets and disrupt ro jam the oscillation. Also, is is necessary that the grove cut into the back of the slider, which acts as a receiver for the shaft coming from the motor, fits the guide on the end of the shaft perfectly in the lateral direction, but has ample vertical clearance on either side. As the shaft on the motor spins, the guide piece on the end of the shaft moves up and down, and left to right. By making the with of the receiver equal to the width of the guide, then all left/right motion of the shaft is transfered into the motion of the blades. By leaving clearance in the height, the guide can move up and down in the receiver without disrupting the motion of the slider (which should only move left to right).
 +
3. What kind of loading do we expect to be on the component?
 +
* The slider is expected to be subjected to cyclical forces in the lateral direction, switching back and forth from left to right. These forces will create compressive loading on the insides of the sliders receivers.
 +
4. What measures can we use to evaluate performance?
 +
* The efficiency of the slider can be evaluated by determining how much of the power generated by the motor shaft is transfered to the cutting blades. Also, the consistency of its motion can be analyzed as well to determine how smooth its operation is.
 +
[[Image:slider.jpg]]
  
 +
=='''Motor  By Toby Cressman'''==
  
 
+
1. What decisions were made in the design of this component/module?
 
+
* When choosing a motor the first decision would have to be what size motor, power wise, do we need to   cut through our desired material.
 
+
2. What are the critical features and dimensions? (It may help to annotate the screenshot of the CAD rendering.)
 
+
*It is critical that the motor fits inside the sized casing for the scissors. It is also important that we have a motor that is not to heavy. We do not want the product to be uncomfortable to hold.
 
+
3. What kind of loading do we expect to be on the component?
 
+
*There will be a torque applied to the motor depending on the force applied to the blades or jaws of the scissors.
 
+
4. What measures can we use to evaluate performance?
 
+
*We can measure the amount of torque the motor can produce and how long the motor can run on its charge.
 
+
[[Image:motor1_pro.jpg]]
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
[[Image:DVAdvanceSide.jpg|left|thumb|500px|Side View]]
+
 
+
==Cool Animated Videos==
+
 
+
<embed src="http://www.youtube.com/v/8_iTSznToHU" type="application/x-shockwave-flash" width="425" height="350"></embed>
+
 
+
Animated Printer Carriage
+
 
+
[[media:DVDriveBelt.avi|Right-click here and select "Save Link As" to download the video (.avi)]]
+
 
+
<embed src="http://www.youtube.com/v/iayt04lR08E" type="application/x-shockwave-flash" width="425" height="350"></embed>
+
 
+
Animated Paper Feed Mechanism
+
 
+
[[media:DVGear2.avi|Right-click here and select "Save Link As" to download the video (.avi)]]
+
 
+
==Analysis==
+
===Analysis Of The Belt System===
+
 
+
'''Scope of Analysis'''
+
 
+
The two engineering specifications that are quantified for the printer belt tensioning system, are the force on the belt required to accelerate the printer head to its maximum speed, and the force to stop the printer carriage and change direction. Both of these specifications pertain to the Dots Per Inch design parameter. The best design is to obtain the maximum DPI rating in the quickest printing time. To achieve this goal, the belt must be able to cope with the forces to accelerate the printer carriage. 
+
 
+
 
+
'''Key Properties'''
+
*Printer Prints 4 pages a minute at 300 DPI
+
*Mass of Carriage With Ink Cartridge = 0.14 kg
+
*Moment of Inertia of Pulley = 0.5 (.002kg)(0.005^2m) = 2.5 x 10^8
+
*The belt is a trapezoidal design, meaning each tooth has the shape of the trapezoid 
+
*The belt is made out of polyurethane which has good wear resistance and low friction
+
 
+
 
+
'''Assumptions'''
+
 
+
Friction force exerted by the slider on the carriage is always constant when moving, and should have been reduced to a minimum by the manufacturer. Lower friction would reduce the force the stepper motor has to supply to move the carriage. Since it is difficult to measure the exact amount of friction force, and it is relatively small compared to the acceleration forces, friction can be neglected.
+
 
+
 
+
'''Finding The Speed'''
+
 
+
Since, the actual printer head speed I could not be found, a few assumptions had to be made with the available information. The printer has a 300 DPI rating, which means that it can print 90,000 dots per square inch. It can print 4 pages of text per minute. Assuming that it prints 8.5” x 11” pages with a 1” top and bottom margin, and 1.25” side margins, it leaves a total of 54 square inches of text. This equates to 4.86 x 10^6 dots per page. Multiply the dots per page by the pages per minute, and that results in 2.43 x 10^7 dots per minute. 2.43 x 10^7 dots per minute is the average printing rate for the printer. However, if we assume the format is 12 point, Times New Roman font, the total area per line of text is 1.95 in^2 (6.5” x .3”) 0.54 square inches per page multiplied by 4 pages per minute, divided by 1.95 square inches per pass, and taking the reciprocal, yields .009 minutes per line, which is 0.54 seconds per line. Every line is 6.5 inches long, which means that the printer head moves at 12 inches per second. Since information on the acceleration of the printer carriage could not be obtained, it was instead estimated. After careful observation of other inkjet printers, the carriages reach their top speed almost instantaneously, so it was estimated that it takes 0.2 seconds to reach maximum velocity, and 0.25 seconds to stop and change direction. 
+
 
+
 
+
'''Calculations'''
+
*Acceleration of Carriage From Rest
+
Acceleration of Carriage = max velocity/ time = (0.3048 m/s) / 0.2 s = 0.15 m/s2
+
 
+
Mass of Carriage With Ink Cartridge = 0.14 kg
+
 
+
F = ma = (0.14)(0.15) = 0.021 N
+
 
+
 
+
Therefore, it takes .021 N to accelerate the carriage from rest to the max velocity
+
 
+
*Stopping and Changing Direction
+
Change in velocity = (0.3048+.03048) = 0.6096 m/s
+
 
+
Change in Time = 0.25 s
+
 
+
F = (Mass*Change in Velocity)/ Change in time = 0.34 N
+
 
+
 
+
Therefore, the maximum force exerted on the belt due to the change in direction is 0.34 N.
+
 
+
 
+
As seen in Figure 10 below, the maximum force to pull the carriage is related to the torque supplied by the motor pulley. Furthermore, the carriage is fixed to one side of the belt, so it translates directly with the belt. During the analysis, the entire carriage is treated as a point mass and represented as a block. Figure 11 shows the free body diagram of the motor pulley. It is evident that the torque from the pulley is directly related to the force on the belt during acceleration.  
+
 
+
[[Image:DVFBD1.jpg|left|thumb|400px|Figure 10: Free Body Diagram Of System]]
+
[[Image:DVFBD2.jpg|left|thumb|200px|Figure 11: Free Body Diagram Of Motor Pulley]]
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
The analysis through ''Adams'' produced results that were similar to the calculated values. The maximum force, as seen in Figure 12, reached 1 N which was very close to the calculated value of 0.34 N.  
+
 
+
[[Image:DVForceBelt.jpg|left|thumb|600px|Figure 12: Force of the Drive Belt During Acceleration]]
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
'''Improvements'''
+
 
+
To increase the maximum force that the belt could handle, a few options are available. The cross-sectional area could be increased to decrease the stress on the belt. According the stress equation, stress = load / area , the stress can be reduced by increasing the cross sectional area to compensate for load force. The cross sectional area can be increased by making the belt wider or thicker. Making it wider would be more beneficial because it would provide a greater surface area for the toothed pulley to grip onto. The drawbacks for increasing the surface are the increase in stiffness and cost of manufacturing. Making the belt thicker would reduce its flexibility, making it harder for it to move around the pulley. It would require more torque form the input motor to compensate. Making the belt wider would force the pulleys to be wider, which drives up the cost of the system.
+
 
+
Another method to increase the stress capacity of the belt would be to use a curvilinear design instead of the current trapezoidal design. The curvilinear design looks very similar to the gear sprocket of a bicycle. Instead of a trapezoid shape, the curvilinear design uses a half circle shape. Therefore, the teeth are deeper in the gear which makes it less probable for tooth jumping during high accelerations. Furthermore, there is less material at the edges of the gear, which lowers the moment of inertia, allowing the gear to accelerate faster. [1]
+
 
+
 
+
[[Image:DVNewBelt.jpg|left|thumb|600px|Figure 13: Photoelastic Stress Pattern [1]]]
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
 
+
Figure 13 shows the photoelastic stress pattern of both designs, and it is evident that the curvilinear shape distributes stress more evenly. This is due to the larger tooth cross section. Since the curvilinear shape handles stress better than the trapezoidal shape, a narrower curvilinear belt could be used in place of a wider trapezoidal belt, thus, saving material and cost. [1] The trade off may be in increased cost to manufacture, since curvilinear belts are not as common as trapezoidal belts.
+
 
+
A final option to consider is to change the material of the belt. Using a more durable and stress resilient material such as steel or composites, may work better. However, it is most likely that these materials are more difficult to manufacture, which increases the cost
+
 
+
 
+
==References==
+
[http://www.sdp-si.com/D260/PDF/part1.pdf#page=45 (1) SDP/SI : The World Of Timing Belts]
+
 
+
 
+
 
+
 
+
===Power Scissors===
+
 
+
 
+
'''User Requirements'''
+
 
+
a. Blades are sharp enough to cut different materials
+
  i.   Have a sharpening function
+
b. Easy to use
+
  i.   Has a low weight
+
  ii.   Has a small size
+
  iii.   Comfortable to hold
+
  iv.   Wireless
+
  v.   Easily accessible buttom to start
+
c. Aestheically Pleasing
+
  i.   More likely to be bought
+
d. Long battery life, chargeable
+
e. Changeable blades for different materials to cut
+
f. Doesn’t break if dropped
+
 
+
'''Engineering Specifications'''
+
1. Material for jaws is sharper than cutting materials strength.  This corresponds to E.
+
2. Battery Life is ______ long.  This correspsonds to D.
+
3. Force of scissors is greater than _____.  This corresponds to A.
+
4. Weight is less than _______ (5 lbs?).  This corresponds to B. 
+
5. Scissors retain sharpness for _______ (amt of time).  This corresponds to A.
+
6. torque on motor is ______.  This corresponds to A. 
+
7. External casing can withstand ______ force, to avoid being dropped.  This corresponds to F.
+
8.      A certain percentage of people when surveyed said that the scissors are pleasing.  This corresponds to C.
+

Latest revision as of 13:47, 20 February 2008

Contents

Power Scissors Dissection

Overall1.jpg

Function

The primary function of the Power Scissors is to cut through different materials. There are two blades, the bottom one stays stationary, and the top blade moves rapidly, opening and closing. This action allows the tool to cut through different materials.


Parts

The table belows lists the components for the Black & Decker Power Scissors.

Table 1: Power Scissors Component List
Part # Part Name Category Function Material Picture
1 Motor Input Serves as Power Supply for blades
Motor.jpg
2 External Casing Structural Component Protects internal components and holds them together Plastic
Complete open.JPG
3 Jaws Ouput The bottom blade remains stationary, while the top blade moves continually up and down Steel
Jaws.JPG
4 Battery Input Provide power to motor Wrapped in cardboard
Battery.JPG
5 Cam Motion Conversion This forces the bracket to move by translating rotation motion of the motor, to translational movement in the bracket. The bracket then causes the upper blade to open and close Plastic
Yoke.JPG
6 Screws Structural Holds Casing Together Metal
Screws.JPG
7 Bracket Support element Ball and socket joint limits movement of jaws. The socket is ovular so it allows some movement of the jaws. Plastic
Blade housing.JPG
8 Button (spring) Motion Conversion Closes switch to start motor by closing circuit. Button – plastic

Spring – metal Switch - metal

Customer Requirements

  • Blades are sharp enough to cut different materials (1)
    • Have a sharpening function
    • Changeable blades for different materials to cut
  • Easy to use (2)
    • Has a low weight
    • Has a small size
    • comfortable to hold
    • Wireless
    • Easily accessible buttom to start
  • Aestheically Pleasing (3)
    • More likely to be bought
  • Long battery life, chargeable (4)
  • Doesn’t break if dropped (5)

Engineering Specifications

  • Material for jaws is sharper than the intended material to cut
    • Corresponds to blade sharpness (1)
  • Batteries last for 4 hours of continuous use
    • Corresponds to long battery life (4)
  • Force of scissors is greater than 5N
    • Corresponds to ability to cut through material (1)
  • Weight is less than 5 lbs
    • Corresponds to easy to use (2)
  • Scissors retain sharpness for 40 hours of use
    • Corresponds to blade sharpness (1)
  • Torque on motor is great
    • Corresponds to ability to cut through material (1)
  • External casing can withstand force from being dropped
    • Corresponds to long-lasting (5)
  • 90% of people surveyed found the scissors pleasing
    • Corresponds to Aesthetically pleasing. (3)

Scissor Jaws by Laura Chernak

Scissors.jpg

1. What decisions were made in the design of this component/module?

    • In making this component it was important to find a way to create jaws for cutting that moved rapidly. It order to solve this problem the jaws were made so that only the top jaw moved, while the bottom remained stationary.

2. What are the critical features and dimensions? (It may help to annotate the screenshot of the CAD rendering.)

    • Critical features of this component are the dimensions that correspond to the shape of each jaw. The angle of the blades could also be measured, as well as the thickness to the part. The angle of the blade affects the sharpness of the tool, and the thickness affects the load that can be withstood. Another important feature was the angle that the jaws could open to, an attribute that is important to ensure that the tool is safe.

3. What kind of loading do we expect to be on the component?

    • Loading can be expected from the material trying to be cut. The force of the cutting, and the resistance of the material to be cut will create stress on the component.

4. What measures can we use to evaluate performance?

    • To evaluate the performance of the jaws they should be tested regularly for sharpness. It is important that the jaws retain sharpness so that the tool can perform its function to cut through material. This can be tested by determining the forces necessary to cut through various materials. It is likewise important that the jaw is functioning properly and not opening at too large of an angle, as this will deter from the safety of the tool. This can be measured by determining the angle at which the jaws open.

Slider Mechanism by Victor Ceci

Sliderfront2.jpg

1. What decisions were made in the design of this component/module?

  • It is clear that the decision was made to make the slider mechanism as simple as possible. Essentially it seeks to turn the rotating motion of the engine shaft into reciprocation motion perpendicular to the shaft with as little parts as possible, most likely to improve weight, cost, and packaging properties of the product.

2. What are the critical features and dimensions? (It may help to annotate the screen shot of the CAD rendering.)

  • It is important that the slider is long enough to provide adequate clearance on either sides of its receivers. This ensures that as the slider moves back and forth between its holding brackets, that the receivers (which protrude from the slider), so no contact the brackets and disrupt ro jam the oscillation. Also, is is necessary that the grove cut into the back of the slider, which acts as a receiver for the shaft coming from the motor, fits the guide on the end of the shaft perfectly in the lateral direction, but has ample vertical clearance on either side. As the shaft on the motor spins, the guide piece on the end of the shaft moves up and down, and left to right. By making the with of the receiver equal to the width of the guide, then all left/right motion of the shaft is transfered into the motion of the blades. By leaving clearance in the height, the guide can move up and down in the receiver without disrupting the motion of the slider (which should only move left to right).

3. What kind of loading do we expect to be on the component?

  • The slider is expected to be subjected to cyclical forces in the lateral direction, switching back and forth from left to right. These forces will create compressive loading on the insides of the sliders receivers.

4. What measures can we use to evaluate performance?

  • The efficiency of the slider can be evaluated by determining how much of the power generated by the motor shaft is transfered to the cutting blades. Also, the consistency of its motion can be analyzed as well to determine how smooth its operation is.

Slider.jpg

Motor By Toby Cressman

1. What decisions were made in the design of this component/module?

  • When choosing a motor the first decision would have to be what size motor, power wise, do we need to cut through our desired material.

2. What are the critical features and dimensions? (It may help to annotate the screenshot of the CAD rendering.)

  • It is critical that the motor fits inside the sized casing for the scissors. It is also important that we have a motor that is not to heavy. We do not want the product to be uncomfortable to hold.

3. What kind of loading do we expect to be on the component?

  • There will be a torque applied to the motor depending on the force applied to the blades or jaws of the scissors.

4. What measures can we use to evaluate performance?

  • We can measure the amount of torque the motor can produce and how long the motor can run on its charge.

Motor1 pro.jpg