Band-Beesten rolling drum set

This is an interdepartmental effort to create a fully mobile drum set for use by the Vandal Marching Band.
==Final Design==
Photo	Overview
 	Full Assembly
*Overall weight: 100lbs
*Painted wooden frame
*Three rotating Omni-Ball assemblies
*Three battery powered LED light strips with manual control switch
*Drums mounted to one central location
*Movement via push or pull from the back end
*Videos:
**Performance - November 9th, 2013
**Practice - Novermber 8th, 2013
 	Omni-Ball Wheel Assembly
*Designed based on results from the Friction Testing
*Basketballs used for grip on multiple surfaces
**Surfaces included: hard floor, asphalt, turf etc.
*Three sets of double omni-wheels at 50o
*Three single omni-wheels
*Three identical interchangeable arms
**Attached to hub with pins for easy removal
**Each supported by two shoulder bolts and three regular bolts
*Hub had a press-fit bearing at its center
*Document Archive contains full drawing package
 	Frame
*Strong pyramidal shape
*Wooden, painted glossy black
*Had central drum support near center of gravity
*Cymbals mounted to separate drum bar
*LEDs powered by seven rechargeable batteries
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==Team Members==
Photo	Members
 	Pictured from left to right: 
*Miguel Martinez, M.E.
*Jonathan Rompala, M.E.
*Hayden Hanzen, M.E.
 	Pictured from left to right: 
*Theo White, M.E.
*Jack Housely, M.E.
*Nadine Morasci, M.E.
*Scott Blee, M.E.
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==Background==
The original idea for the project began a few years before the Fall of 2011 by Dr. Edwin Odom, Professor of Mechanical Engineering, and Dr. Daniel Bukvich, Professor of Percussion and Music Theory. The plan was to collaborate between their disciplines and create a finely tuned, expertly engineered drum set that is fit for a full on-field marching band performance.
The Fall of 2011 marked the initial experimentation and design of the Beest by a Capstone Design team in the engineering department. These initial tests provided insight on what worked well and what needed improvement. The final design from this year was never seen outside of the engineering buildings on campus, but the following year's goals were clear and a new design began immediately. For more in depth design details refer to the Team Drum Roll webpage.
The Fall of 2012 marked the first public introduction of the Beest, which has become a yearly project in the Capstone Design process. Dan Mathewson, a University of Idaho graduate student, designed and utilized a robotic, power driven front wheel that responded to the drummers input and included brightly lit led's on the forward facing drums. It successfully astounded the audience and fulfilled the requirement of marching with a wheeled drum set, but it could still be improved. Dan's thesis can be found in the References section.
The goal of the 2013 Band-Beesten Experience team is to recreate the Beest to operate fully under the drummer control without the robotic assistance while making it bigger and better than before.
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==Design Specifications==
:Carry at minimum:
::*One 14” diameter, 8” deep, 8lb Timbale
::*One 15” diameter, 8” deep, 9lb Timbale
::*One 14” diameter, 4” deep, 13lb snare
::*One 18” diameter, 4lb cymbal
::*One 19” diameter, 7lb roto-tom
:General features:
::*Move in all directions on a single plane (forward, backward, side to side, and radially)
::*Move freely in those directions at marching speeds up to 2 m/s
::*Adjust to a wide range of user heights 
::*Lightweight, ~100lbs
::*Free-standing
::*Human powered (No motored assistance)
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==Project Learning==
Interviewee	Overview
Dan Mathewson
Graduate student who worked on 2012 Band Beesten model	
Frame and Omni-Wheel Tips
:*Single omni-wheels were used because he wanted a constant contact surface on the ball for the drive system, which also reduced the cost.
:*Suggested exploring other omni-wheel configurations and testing to see which is more efficient/easy to maneuver. Such as:
::*Oriented toward the center of the ball
::*Perpendicular to the center of the ball (2012 configuration)
:*Recommended a more rigid frame to prevent leg bending
:*Cymbal hardware and drum clamps are very heavy and could use a redesign
Denise Bauer
Professor of Mechanical Engineering with an emphasis in Human Factors'''	
Operational Factors
:*User comfort is very important, create a mock-up then test it with the potential users to get feedback
::*Develop a rating scale to measure comfort and effort required for operation
General Facts
:*Getting in and out of the apparatus needs to be simple
:*Most products on the market are designed for the 95th percentile male
:*The lower body can produce more power than the upper body
::*Since the upper body is weaker, using it to push a machine may be hard on the back
::*If the control is through the hips the upper body will have more mobility to operate the drums
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==Design Development==
===Wheel Design===
:Problems from 2012:
::*Needed power assistance to roll omni-wheels
::*Basketball lost air occassionally
::*Plastic balls on back did not roll well on turf
::*Metal casters became dirty and would not spin properly depending on orientation
:Improvements for 2013:
::*Find a lower friction alternative setup for omni-wheels and casters
::*Allow for high loads on each wheel
::*Each wheel must roll smoothly on various surfaces, especially turf
::*Basketball testing to prove/disprove it as a viable option
Design 	Description	Pros/Cons
 	Visualization Test Platform
A small test platform test was created with thin bent brackets bolted onto angled wood blocks.
Three of these were created and oriented so that the wheels would touch a ball at roughly the same angle.
The ball was then rotated by hand to see how the orientation functioned.	Pros:
::*Revealed that the omni-wheels had small gaps that affected the rotational direction of the ball
::*Good for visualizing new orientations
Cons:
::*The brackets were flimsy and bent easily
::*Not measured to the accuracy that is needed for a test
::*Not adjustable
::*Can't support realistic weights
 	Initial Wheel Concept
This is a concept render of a possible solution to the ball wheels.
This idea uses six ball casters, three on each of the top and bottom rings.
Each ring is connected rigidly in a triangular shape with a series of tubes and clamps, while using the weight of the drum set to keep the ball in place.	Pros:
::*Using invertable casters could greatly lessen friction
::*Keeps wheel in place
::*Easy setup and manufacturing
::*Very lightweight
::*Stable wheel design
::*Helps visualize other viable options
Cons:
::*No easy way to mount drums or percussionist
::*The moment on each leg would be very large if weight was placed near the center and could break
::*Dirt may ruin casters quickly
::*Overall not practical
center|200px|Friction test platform with casters thumb|center|200px|Friction test platform with omni-wheels	Friction Testing Concept
These are renders of the platform used to test the friction coefficients of casters and omni-wheels.
The apparatus allows for the use of both casters and omni-wheels, and their position can be adjusted to find the optimal settings.
The omni-wheels can be rotated in 90o increments to test for the most effective orientation.
An electronic fish scale will be used to measure the amount of force needed to pull the apparatus across a table.
The test is explained in more detail in the Omni-Wheel/Ball Caster Friction Testing section below.	Pros:
::*Allows many angles and orientations
::*Allows testing of omni-wheels in pairs and as singles for comparison
::*Strong enough to stay rigid during testing
::*Will give us insight into what arrangement to use on the final design
Cons:
::*Balancing the apparatus may be challenging
::*Fabrication may be time-consuming
center|200px|Final concept render to be manufactured 	Final Concept
This is a final render of the omni-ball assembly devised after the tests.
It requires three, vertically oriented, double omni-wheels spaced evenly along the upper portion of the ball as well as three single omni-wheels along the under section to provide support.
The angle of the top tier of omni-wheels is measured at 50o from the equator of the basketball, while the lower supporting wheels are on the equator.
The lower omni-wheels are spaced 1/4 inch from the ball and are only in place as support to prevent the ball from escaping. 
All of the arms are identical, interchangeable, and easy to manufacture in large groups.
The inner hub contains a bearing that will allow the wheel to rotate toward the most natural orientation.	Pros:
::*Lightweight, minimizes material
::*Easily manufacturable - interchangeable parts
::*Resists bending from force direction
::*Bearing reduces stress while turning
::*Easy to assemble/disassemble
::*Operates under heavy loads
Cons:
::*Expensive
::*Ball must be over pressurized to prevent escape
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===Frame Design===
:Problems from 2012:
::*Raised body made drum arrangement difficult for percussionist
::*Each leg delayed movement slightly in all directions
::*Not easy to customize instrument type or layout
::*Overweight and bulky, not easy to transport
::*Not visually appealing or ergonomic
:Improvements for 2013:
::*Lower center of gravity of full setup
::*Rework drummer input system
::*Stiffen wheel attachment for a more immediate response to movement
::*Improve possibility of customization
 Table of Frames . . . . . . . . . . Score 1 - 5 . . . . . . . . . . 5 = Best
Condition (right)
Shape (below)	Strength	Manuf.	Appear.	Combine.	Drum Arrange.	Step Range	Harness Attach.	Total
	5 	5 	3 	5 	5 	3 	5 	31
	3 	4 	3 	2 	4 	4 	4 	24
	3 	2 	5 	1 	3 	5 	2 	21
	4 	3 	5 	3 	4 	4 	3 	26
	4 	5 	4 	5 	5 	5 	5 	33
Design 	Description	Pros/Cons
thumb|center|200px]| Harness test]] 	Hexagon, Frame Version 1
The Hex-like shaped frame is the top choice from the table above.
It was built out of wood and metal brackets, with casters in three corners.
It should be noted that it is not a perfect hexagonal shape.
The angle at which the casters are connected is 135o, while the others are 105o.
These angles were chosen to provide optimum step range with a drummer in the center.
The lower picture is a test of an all strap/rope drummer connection at three points on the frame.	Pros:
::*Large and stable
::*Easy movement forward/back and side-to-side with ropes
::*Allows upper body freedom
::*Easy manufacturability
Cons:
::*Too big to be practical
::*No good way to mount drums
::*Corners without casters proved to be very weak
::*Rope has severe inertial issues while rotating
::*Difficult to "strap in" to harness
thumb|center|200px]| Triangular concept render, version 2]] 	Triangle, Version 2
This is a render of a triangular frame design that was conceptualized.
The triangular frame shape is the second choice from the above table.
The triangle shape should provide more strength than the hexagon.
Instead of a beam connecting the two back wheels directly, the beam goes up to a harness connection point.	Pros:
::*Very lightweight (about 20 lbs without wheel assemblies)
::*More rigid than hexagon shaped frame
::*"Direct" connection to harness eliminates major inertia issues
::*Harness attachment is near the frame's center of gravity, improving maneuverability
::*Aluminum tube is inexpensive and readily available
Cons:
::*The frame is not currently collapsible due to welding connections
::*Frame is large and could be awkward to maneuver
::*Manufacturing may be difficult and time consuming
thumb|center|200px]| Triangular frame concept render, version 3]]	Tetrahedron, Version 3
This is a second version of the triangular frame design.
Similar to version 2 but slightly smaller in volume.
The two arms reaching around the drums are "multi-bars" that allow for cymbal attachment or various other accessories, ie. cow bells or wood blocks.
The accessories could also be attached directly to the drums along their rims.
Manufacturing could be simple, with basic cuts and welds to each part at their respective angles.	Pros:
::*Similar "Pros" as frame version 2 seen above
::*Sturdy base and wheel connections
::*Good weight distribution
::*Center of gravity is near center
::*Harness height can be adjustable
::*Large step size accommodates motion in any direction
::*Lightweight
Cons:
::*Not collapsible if welded
::*Less room for drum mounting
::*May require additional support if weight is not centered
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==Testing==
Test Photo 	Overview	Results
 	Fishing Scale Correlation Testing
Objective:
We needed an equation that correlated the voltage output of the fishing scale to the force of the pull.
Set-up:
A fish scale is being used to measure the force required to move the wheel testing apparatus.
In conjunction with the scale, there is a DATAQ-155 data acquisition device that can be connected to a computer to record the voltage changes of the pulling force.
In order to use this and accurately measure the force for each pull it needs to be calibrated and an equation formulated for the final test.
A more detailed explanation can be found in the final report:
Fishing Scale Report	The data was compiled in Excel and the final correlations were calculated.
They can be found in the link below:
Fishing Scale Results
 	Omni-Wheel/Ball Caster Friction Testing
Objective:
We needed to find the optimum wheel type, orientation, and angle placement to produce a ball wheel with the lowest friction possible.
Set-up:
The apparatus is pulled with the fishing scale to measure the force needed to move the wheel from a resting position.
Three types of wheels are being tested, single omni-wheels, paired omni-wheels, and ball casters.
The types will be tested using angles ranging from 40o up to 55o, and the omni-wheels will be oriented either vertically or horizontally.
Once the forces are recorded and the apparatus is weighed, the friction can be calculated for each variation.
For the full test explanation, see the final report:
Friction Testing Report	The test revealed that the friction reduces as the angle rises.
The best orientation for a final product is with the paired omni-wheels in the horizontal orientation at 50o from the equator of the basketball.
This orientation is deemed best as long as there are supporting wheels below the equator to prevent the ball from rolling off of the wheel base.
See more detailed results below:
Friction Testing Results
center|200px|Frame Version 3	Tetrahedron Frame Testing
Objective:
We needed to create a physical mock-up of the frame to find flaws and work on improvements before creating the final design.
Set-up:
This frame was a wood mock-up of version 3 seen in the Frame Design section above with slight modification for visualization purposes.
It was built with wood donated and cut by the College of Natural Resources, and was pieced together using various screws and brackets.	
The mock-up worked well and provided a chance to modify it quickly and reinforce where necessary.
Due to time constraints, this frame became part of the final design.
It could use some further redesigning and testing to be more complete and easier to recreate but worked well for the purposes of this project.
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==Document Archive==
Fishing Scale Report
Fishing Scale Results
Friction Testing Report
Friction Testing Results
Omni-ball Drawing Package
Finale Photo
==References==
Team Drum Roll, 2011
Band-Beesten news story, 2012
 Dan Mathewson's Thesis
Category:Capstone design