automatic page turner

Automatic Music Stand Page Turner

By Group 6:

Jee Gun Kim

Rex Lu Robert Carlo Millan

Alvin Tai

Prepared for:

Professor Ken Youssefi ME130, Design of Planar Machinery May 9, 2006

ME 130: Design of Planar Machinery Spring 2006

Group 6 Automatic Page Turner

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Background Professional and amateur alike, most musicians have experienced reading sheet

music that typically span several pages and are usually in some type of bound form. Thus, in order for smooth transitions between pages, musicians need a method to turn a page without interfering with their performance. This is usually done with the

help of a page-turning assistant. However, for most musicians an assistant may not always be readily available. A mechanism mounted directly on the music stand that turns the page at the push of a foot-operated button will render the assistant unnecessary and obsolete.

Task Assignment

Group Member Task Jee Gun Kim • Initial design of mechanism

• Mechanism synthesis

• Acquire music stand • Kinematics analysis of design • Write written project

• Work on poster

Rex Lu • Draft design by hand • Acquire material for links

• Attach motor to the mechanism

• Machine the mechanism • Assemble the mechanism

• Work on poster

Robert Millan • Machine the mechanism

• Acquire motor and wood

• Cut plywood • Assemble the mechanism

• Make the poster presentation

Alvin Tai • Initial design of mechanism • Create 2D drawings using AutoCAD • Create 3D drawings using SolidWorks

• Acquire material used to lift page

• Machine the mechanism • Write written project

• Work on poster

List of Specifications/Requirements

The following is a list of specific design criteria that we tried to accomplish with our mechanism. These specifications and requirements were created in the beginning of

the project and our conceptual designs were developed to achieve these goals.

For final product:

• Non-distracting quiet and fast operation • High reliability, to prevent malfunction during performance



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• Compact design • Detachable from stand

• Battery operated

• One page turn per pedal depression For this project:

• Confirm functionality of design • Turn a page in a book of music notes • Turn several pages in succession • Not all final product functional requirements may be met

Conceptual Designs The main concern with creating an automatic page-turner was the mechanical ability to distinguish individual pages. Without any sort of electronic technology there were

only a limited number of ways to do this. Here are a couple of aspects that we

discussed during our brainstorming session (Appendix):

• Vacuum suction

• Magnetic attraction • Surface Roller • Surface Friction contact

Vacuum suction The idea behind a vacuum suction is that it would effectively separate the top page

from the rest of the book. The disadvantage to this type of method is that it would create unnecessary noise that would interrupt a musical performance. It would also

need to be incorporated into the 4-bar mechanism and integration would be difficult to implement.

Magnetic Attraction For this concept, we thought that we could attract individual pages off the bound

book and then create a turning device based on the magnetic attraction. The advantage to this concept would be the ability to move pages without physical

contact with the page. However, this turned out to be a difficult quality to control as

it was still difficult for the magnet to distinguish between the pages. Another disadvantage was the necessity to “prep” the music book with magnetic materials.

This was decided to be an impractical design.

Surface Roller This was a concept based on many inkjet printers out on the market. With a rubber

roller, a printer can effectively remove a single sheet of paper. Even without a 4-bar

mechanism, this would work well. However, unlike a printer, our device cannot cover a certain amount of space since allowing full visual contact with the sheet music is crucial for a musician; a roller would block too much space on the book.

Surface Friction Contact Our final conceptual design worked perfectly with the class requirements and the

necessary movement. The idea behind this was that we would have two main parts

of the mechanism. A rocker would lift a single page with a high-friction material (much like rubberized finger turners) while the crank would sweep underneath the lifted page for a complete page-turn. This acts similarly to the mechanism and



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motion of a windshield wiper; on a car, one arm acts to collect the water and the other arm sweeps the collected water off of the windshield. We developed two

designs for this concept: one that would work from the bottom and one that would

work form the top. We decided to design the former due to the limitations of the musical stand that we were working on. It was easier to attach a mechanism at the top rather than the bottom due to the protruding lip that the music book rests on.

Introduction

Our automatic page-turner uses a 4-bar mechanism as the foundation of the design. To create a mechanism that would turn a single page in a music book requires first distinguishing the pages within the book. The completed mechanism consists of two

main parts: a rocker that initially lifts a single page and a crank that finishes the entire page turn. To lift a single page, the rocker has a substance called “Paper Tak” which creates a high friction surface for effective page lifting. Because the majority

of musical instruments are played with the hands, we added a foot pedal that would

allow uninterrupted page transitions.

Detail Design The mechanism is a Grashof crank-rocker designed using a two position synthesis of

a four-bar crank and rocker to give 68 degrees rocker rotation with equal time

forward and back, from a constant speed motor input. The 68 degrees came from first, determining the horizontal distance between O2 and O4 as 7 inches, and then

trying to lower the position of O4 as much as possible. Figure XXX below shows the extreme right position of the rocker arm.



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Figure 1. Synthesis of the mechanism.

The velocity analysis was done at an arbitrary position of the mechanism using the

velocity polygon method. Since the angular velocity of link 2 was not available

during the time of the analysis, the other angular velocities and the velocities of the joints were found in terms of the angular velocity of link 2.



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Figure 2. Velocity analysis at an arbitrary position.

Drawings

Refer to appendix.

Bill of Materials

Item Quantity Description of Use

Cost

Manhasset Music

Stand

1 Stable base for

mechanism

$32.49

1/8” by 3/4” by 8’ aluminum

1 Material for linkages

$30.99

3/8” Plywood, 10” by 10” square

1 Base for motor and linkages, mounts to stand

$0.00

4” by 4” by 10” wooden beam

1 Material for offset wedge and blocks

in pedal

$0.00

Electric motor 1 Drives the crank $0.00

2” diameter 1 Link 2, connects to $0.00



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aluminum rod, 3”

long

motor shaft

Paper Tack 1 Adhesive used to pick up page

$4.00

3” door hinge 1 Hinge in foot pedal $4.55

Battery Holder 1 Holds AA batteries for easy wiring

$0.00

AA batteries 4 Power for the motor

$0.00

Mini Breadboard 1 Mount for resistors $0.00

10 ohm Resistor 3 Varies the speed of

the motor

$0.00

Compression Springs

5 Provides counter force in pedal,

mount for paper tack

$0.00

Total $72.03

Discussion & Future Modifications

During the design phase of our mechanism, we encountered a couple problems that

ultimately led to our final design. The following is a summary of the problems and solutions that were developed during the design of this device:

• Offset plane: We noticed that with a crank and rocker operating on the same plane as the music book created a problem. If the sweeping page-turning arm (crank) were to be on the same plane as the book, it would

eventually hit the book binding rather than sweep a single page. This also

proved to be a difficult problem to solve since we weren’t qualified to design 3-dimensional mechanisms. We finally decided to create an angled wedge (Figure 3) that would offset the operational mechanical plane. This would

allow the rocker to maintain physical contact with the page while permitting the crank to sweep individual pages.

• Maintaining rocker contact: Because the mechanical plane is slightly offset,

we wanted to have the rocker to stay in contact with the page for as long as possible. We initially designed a spring-loaded rocker that would force the

arm to maintain physical contact with the page for as long as possible.

However, this was unnecessary as we eventually developed a simplified version that was just as effective, as seen in Figure 3.

Spring Loaded

Rocker



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(a) (b) Figure 3. (a) Initial design for rocker (b) Final design.

• Creating Frictional Contact: The initial design called for a simple eraser to

create a high-friction surface to lift single pages off of the music book. After

several tests with an ordinary notebook, we believed that this would be sufficient. However, when we finally acquired the actual music book that we were going to use, we noticed that there was a flaw in our design. A music

book has very different physical qualities compared to a normal notebook.

The music book has thicker and smoother pages which increases the force needed to separate pages. We began to research different chemical adhesives that would allow continuous reuse without affecting the frictional coefficient

that we needed; some technologies that we looked into included Post-It Notes and masking tapes. We finally found a substance called “Paper- Tak” that is used to hang/hold delicate pictures without damaging the photos. These were

reusable and maintained a high-friction surface for our design.

• Motor Speed: Our final problem arose with our electric motor that we used

drive the crank. We overestimated the speed of our initial motor and the mechanism failed to lift the page. This occurred because with a higher speed,

the adhesive (Paper-Tak) wasn’t able to “grab” the page from the music book. The kinetic friction was too small to pick up the page, and the speed of the

motor didn’t allow us to operate in the static friction region. This was an

unforeseen problem and the design had to be modified with a lower RPM motor that could provide more torque.

Future Modifications There are two aspects of our current design that can be modified in the future to

increase the effectiveness of the automatic page-turner. It would be beneficial to find a solution to minimize the noise created by the mechanism since it will probably be used during musical performances. This can probably be achieved with a more

expensive motor and insulation around the linkages. We do not have the resources to obtain another motor so it was difficult to change this aspect of our design. The linkages also produce noise as they collide with each other during the mechanical movement. This can be minimized by using insulation to prevent contact between

the bars. Another important aspect of the design is the aesthetics of the device. The design

should not be visually disturbing or distracting since it will be mounted on a musical stand. A musician must focus on the composition rather than the sudden movement of this device. In the future, we want this device to become part of the music stand

rather than an accessory. With the right aesthetic design, we can create a less

distracting method of turning pages.

Page contact force



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References Norton, R. Design of Machinery: An Introduction To The Synthesis and Analysis of Mechanisms and Machines. Third Edition New York: McGraw Hill. 2004. Youssefi, K. ME130: Design of Planar Machinery Notes. www.me.berkeley.edu/ME130. Retrieved from the World Wide Web on May 08, 2006.



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Appendix

Hand sketches and conceptual designs



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automatic page turner

Documents

mechanism work

mechanism machine

bar mechanism

page machine

automatic page turner

functionality of design

kinematics analysis

compact design detachable