Marching Band Triangles

The University of Idaho Marching Band will have a new addition to their halftime performances from this point forward, musical triangles. The Mechanical Engineering Capstone group, Pressure Angles has designed and manufactured musical triangles for each band member which feature flashing lights coming from our thoughtfully designed handle that will light up upon being struck. This project incorporates the design, manufacturing, and fabrication of: jigs, musical triangles, chimes, handles with internal circuitry and LEDs, and a sling allowing each band member to keep this rhythmic surprise hidden until they are ready light up the stadium.

=Problem Definition=

Background
The Marching Band has been featured with many capstone projects like the Bandbeesten for many years. But this year, 2019 the Marching Band director Spencer Martin had the idea of bringing the musical triangle back to life. Musical triangles aren't new to the marching band, but their high cost made it difficult to justify implementing them with each member of the band.

The triangles were decided to be made out of constructional rebar to cut cost without sacrificing sound. Mr. Martin wanted the triangles to have some flair so he envisioned a triangle that would have lights that would flash upon hitting the triangle with the chime. To house the electronics and protect them Pressure Angles decided to design a handle for the triangles that would incorporate an ergonomic fit, all of the necessary electronics. Working with Dr. Robert Rinker, Associate Professor and Associate Chair of the Computer Science Department we were able to receive guidance with prototyping the electrical components that go into creating this light emitting response.

With the help and guidance of Dr. Matthew Swenson, Dr. Edwin Odom, Dr. Steven Beyerlein, and Graduate Student Selso Gallegos we were able to develop the handle design to meet all criteria Spencer had in mind while remaining sleek and robust. With the help of the advisers above and machine shop manager Bill Magnie our team was able to developer a jig to create consistently sized triangles to make sure each sounded the same.

Deliverables
The Band Department, led by Spencer Martin, asked the Mechanical Engineering Department to create musical triangles for each band member. The triangles themselves are made out of rebar, and will be held with our custom handles specially designed to house a battery, LEDs, and a sensor that can pick up vibration from contact with the chime to signal the lights to turn on. It is important that each band member can remove and stow the triangle and its components swiftly during performances.

Specifications
By the end of the project Pressure Angles will have designed, manufactured, and fabricated 150 triangle packages. Each package consists of a triangle, handle with functioning electronics, chime, and a holster for everything to fit in.

=Design Considerations=

=Project Learning=

Lights circuit and battery housing
The requirements for the circuit housing are the lights must be visible to the audience, the circuit board and battery must be secure and protected from damage while still giving access to switch on circuit board, and provide enough space to house all electronics.

Perpendicular Design
With this design the light could me mounted directly to the surface board making manufacturing easier and easier to install into the handle. The problems with this design are the storage when not in use and the manufacturability. The storage would have to be fragile because a twisting the part would cause it to break. this would be fixed by using thicker wood but this would rain the cost and lower the manufacturability even more. Using the laser cutter does make them easier to manufacture but this design uses a lot of material making it more expensive.



Compact Design
Design 2 offers a design that is easier to store and make the handle easier to manufacture. The second design has the lights mounted around the otter rim in the form of light strips instead of surface mounted lights. This requires wires to be attached to the circuit board which makes manufacturing the circuitry more difficulty and time consuming. the problem of this is the design has gotten wider then wanted in order to house the components.

Balancing Design
Initial grip design for both options positioned the triangle in the incorrect angle so both designs we modified so the triangle would be perpendicular to the handle in order to face the audience. Design one is a simple designed for both right and left handed people to be able to silence the triangle as needed with being balanced on the thumb and index finger. This design can fit any finger size but can be easily dropped if not careful.

Pinch Design
The second Design is similar to design one but instead offers more of a grip to hold onto. This design is more comfortable but does restrict people with bigger fingers. This grip offers more control when holding triangle but can interfere while playing. what worked with this design is it is very easy to hold onto which will help the band not drop it. What does not work is it takes more material and could make it hard to deaden the triangle.

Sensor Connection
The sensor needs to be attached to the triangle in a way that will not disrupt hot it is played. It is preferred to be able to be removable but it is not a requirement the current plan is to use a magnet to have a removable connection.

Triangle Dimensions
The dimensions of the triangle are key to the sound the first diminutions used for the triangle were 7.35” sides this ended up being too large and hard to reproduce. So in order to make them repeatable the sides were down sized to 7.16”. This did not affect sound quality and made them easier to make. an important piece of this is to be able to manufacture the same triangle 150 times. To do this constant improvements are being made to the jig in order for it to be Consistent. we started with a simple just just to bend the rebar around this worked to make a contant length but the rebar would slide around. to fix this thumb screws were added to hold it in place. then stoppers where put into place to get the correct angle.

=Final Design=

=Validation=

Lights testing
=Team Members=

=Additional Documentation=

Project Schedule



Meeting Minutes

Presentations



Client Interview