My Final Project - BOOM CHIX

Product Description

BOOM CHIX is a set of drum sticks to be used with either a drum kit or drum pad to practice stick control and rudimentary drum exercises at the beginner and intermediate levels. BOOM CHIX will consist of a pair of wooden drum sticks made of oak, hickory, or maple that are equipped with a standard metronome module as well as a device to offer haptic feedback or vibration at the same rate as a metronome. Standard equipment during practice sessions consists of drumsticks, ear plugs, headphones, metronome, sheet music, etc. Most drummers and their instructors are concerned with protecting their hearing as long term exposure to the noise created in a musical performance setting can result in hearing loss in the long term. As result, drummers are encouraged to wear both ear plugs and headphones which makes the metronome difficult to hear. Current metronomes usually exist as a wholly separate device so this product will allow for the elimination of an extra piece of equipment while helping to protect the drummers ears. Furthermore, the haptic feedback module, will allow the drummer to feel a vibration in the hand for each BPM rather than have them listen for a click of the metronome. By combining the metronome feature and haptic feedback features the drummer will no longer have to carry a separate metronome and doesn't have to worry about hearing the metronome as they benefit from tactile training instead. They can then spend more time listening to the music and instrumentation while making the practice of the music tempo a tactile experience. With BOOM CHIX drummers won't just hear the music...they'll feel it too!

Solution to a Pesky Problem

It is quite common for beginner drummers to use removable silicon handles to have a better grip and to avoid dropping their sticks. I believe this can be used as a template for a 3D printed handle which can be made out of hard plastic and potentially house the electronics for the vibrating metronome to be built inside. I believe a larger version of this silicon handle can be created once we do the module on molds and casting to fit over the 3D printed handles.Digikey also has a very large inventory of multivibrators which is something I am currently researching in order to find the smallest version possible so that it can fit inside the housing of the drum stick handles. The metronome type electronics kit seem to be way too large for this project unless the machinery is housed a separate unit and wired to the sticks externally which was my initial idea. After some thought I believe it would be much more effective to have everything housed internally.

2D and 3D Modeling

Initial Pencil Sketch Week , 2D Sketch Using Inkscape & 3D Rending of Promark Drumstick

Planned Construction

After testing several motors I've decided to go with the ERM motor as it seems to have the stronger vibration and takes up less space inside the drum stick of the two options. It was recommended from the global evaluator that I couple the motor with a transistor on the development board so I will be designing a new with a new shape that will better compliment the look of the final prototype. As 5/20 I have all the parts needed for the project. The LED pictured above turned out to be a voltage meter so that was returned and replaced with a 4 digit Adafruit blue LED display. The current development board has lots of extra space so it will be redesigned to be much smaller with a more convenient button layout.

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Beginning to Prototype

I experimented with the silicon drum handles in the photo above but it seems once they are placed over a set of drumsticks they are very difficult to remove so I've ruled those out. I was originially hoping this would create an encasement for the motor which would have a soft feel for the hands. Another option to try was drum stick tape and that is much cheaper and very easy to remove in the event that repairs would be needed. I also ordered a shrinkable wire covering to cover the two wires that will run from the drumstick to the development board while connected to the button motor inside the stick.

I also began to fiddle with cutting into a drumstick and was able to figure out it would be best to use a maple stick instead of oak. The oak wood is much harder and quite to difficult to cut into. I initially was using a 5V rotary tool which turned out not to be powerful enough so I am currently in search of a battery for a 20V Bauer rotary tool.

It seems that I can use the motors from the week we did on output devices however I will need to have about 4 feet of cord for the prototype. I also created a new development board with the Xiao RP2040 microcontroller and a 3 digit digital display. I added 3 buttons so that one button would power on and the other two would function as up and down to increase bpm. I will begin to work on the coding soon to see which adjustments need to made to the components. I also experimented with 3d printing an encasement for the board. So far I have made the bottom, experimental of course but I just wanted to revisit the skills I had learned in Fusion 360 for 3d design.

Prototyping the Chord

I am creating the chord that will run from the development board to the motor inside the drumstick. I am using a 2 wire multiconductor cable in red and black ad will use the black wire to connect to ground on the microcontroller. I spliced the ends of the wires on the red and black ribbon to expose about 1/2 inch. I then did the same to the blue and red wires on the ERM motor. I cut a lenght of 4 feet for the red and black ribbon cable as that would give enough room for the user to freely move while the stick is connected to the control system. I then soldered the connections and secured them with shrinking wire covers to protect and insulate the connection. I then ran the ribbon wire with connected motor through a shrinking cable cover enclosure of a slightly shorter length to allow clear connection to the circuit board without interference. I then used the hot air nozzle at the soldering station to shrink the wire covering around the red and black ribbon cable.

Attaching the Chord & Adding 3D Printed Motor Cover

I first attempted to hollow out a portion of the drum stick using the Bauer rotary tool pictured above. While I thought that would be the main tool, it ended up being used as secondary support. In our lab I found a cutting power tool called an oscillating multi-tool and that seemed to cut things much more efficiently. I learned how to use the tool during the build something big assignment where we used it to cut the tabs created by the CNC machine. I did the majority of the cutting with the oscillating tool and the remained was done by using a rotary blade at an angle to chip away the cuts made by the oscillating tool. I continued to hollow the drum stick until the ERM motor on its cord fit inside with room to spare. Once the opening was big enough I used 3M Brand 220 Grit sand paper to sand the inside of the groove to make sure the stick was smooth and free of splinters.

Next I decided to design a cover for the motor and hollow opening using fusion 360. The purpose of this cover would be to keep the drumstick grips that would be added from sinking into the hollow area on the stick. I used a digital caliper to meaure the length and the width and my first print was too small and also too thin. I adjusted the measurements so that the cover would be thicker, curved, and slight overhang the opening to make it a smoother transition.

The second print in white was the perfect size, so with the ERM motor and cable placed inside the hollow of the drum stick I sealed the opening with the 3D cover using two small dots of hot glue. In this way it would be simple to remove to make repairs.

The drumstick grip tape that I ordered from Amazon needed to be cut to fit the sticks that I am using. One piece of grip tape was long enough to wrap both sticks with a little left over to spare. I removed the protective film on the grip tape to reveal a rubberized non slip grip in a blue, white, and black camouflage color. The grip tape comes with built in double sided adhesive but the adhesive did not stick well so I used double sided tape from the lab to reinforce the grip tape's connection to the stick. I was sure to measure them so that the two sticks would appear to be a part of the same set; same length and same thickness regardless of which stick would have the motor. I used one dot of hot glue from a hot glue gun to seal the final edge of the grip to the stick for smooth finish.

Final Adjustment to Drumstick Hollowing

My instructor suggested that if I used a lathe to create a hollow space for the drumstick that the finished product would not only look neater but also the motor would have a more snug fit without touching the sides of the hollowed out space. I was able to find a drill bit that was roughly same width as the ERM motor and used the lathe to drill a tunnel into the drum stick that was about 1.25 inches deep. This would allow the weighted end of the ERM motor to rotate without hesitation. With this machine several tool such as wrenches and keys are used and each part requires something different. The most important safety instruction for this machine is to be sure that hair, loose clothing, etc are removed or tied back. Remove all jewelry as well because. It is also important that you remove any wrenches and all oversized allen key type tools from the machine before turning it on. Both the wood being cut and the collet on the drill head should be tightened into position before turning the machine on. The end result was a very neat hollow opening and huge improvment over the one I had drilled with the oscillating rotary tool a few days earlier.

Final Materials List

Qty	Description	Link	Price
1	7 Pairs Maple Sticks	Promark Maple Drum Sticks Size 5A	$16.95
1	Drumstick Grip Tape	6pk Drum Stick Grip Tape	$13.48
1	17 pk Miniature Button Motor	17 pk Vibrating Mini Motor 3V	$6.99
1	Expandable Wire Sleeving	Wire Sleeving Blue and Black	$8.99
1	Ada Fruit 4 Digit Display w/ Backpack	Adafruit 4 Digit Blue LED display	$11.95