Once we obtained all of our laser cut components we began construction. A picture of our early base assembly can be seen in the diagram below.
We encountered a number of issues with our final design. First, as you can see in the picture below, the center component was created from two wooden pieces.
These pieces were drilled into another wooden piece at the base of the movable motor component. The issue we had was connecting this piece to the virtual drumhead. We wanted to make this connection as strong as possible to sustain most drum strikes. At first we thought wood glue would be strong enough but after our first final assembly and trial hit by another group we needed something sturdier. So we bought some metal brackets and were able to drill holes in the sides to allow for bolts to hold the connection together. This was working great until half way through the expo when the bolt started to become loose and didn't have the correct wrench to tighten them. The vibrational feedback response became more than we desired.
Now for the electronic assembly we attached a hall-effect sensor to the side of wall which needed to be sanded out for the tight fit. Then attached to our center posts we attached a strong magnet from RadioShack. A zoomed in view of the sensor and magnet can be seen in the following figure.
The placement of the magnet was important to get the maximum range of the sensor. Once all of these issues were solved we moved on to connecting the drumhead to the brackets. A final assembly of our device can be seen in the figure below.
Wood glue was used to finalize the assembly as well as dowel pins to attach a rigid rim to the base components. Another important issue to note is that we had planned on using FSRs to record when and where a drum strike would occur. After many trials we determined that these sensors would not be feasible to sense a strike. It occurs so rapidly that hits would only be recorded if you help it there for a few milliseconds, which would not be a realistic device. So after much discussion we decided to add another hall effect sensor at the center of the head and add magnets to each stick to sense each strike. A picture of our drumsticks with the added magnets can be seen in the figure below.
Similar to the idea of multiple FSRs discussed in our proposal there is room here to add multiple hall effects around the outside of drumhead. Unfortunately, due to the late recognition of our hall effect problem these added sensors were not added. To dampen the sound of a drum strike on the wooden board we decided to use a felt pad which you can see in the results section of our blog.
These pieces were drilled into another wooden piece at the base of the movable motor component. The issue we had was connecting this piece to the virtual drumhead. We wanted to make this connection as strong as possible to sustain most drum strikes. At first we thought wood glue would be strong enough but after our first final assembly and trial hit by another group we needed something sturdier. So we bought some metal brackets and were able to drill holes in the sides to allow for bolts to hold the connection together. This was working great until half way through the expo when the bolt started to become loose and didn't have the correct wrench to tighten them. The vibrational feedback response became more than we desired.
Now for the electronic assembly we attached a hall-effect sensor to the side of wall which needed to be sanded out for the tight fit. Then attached to our center posts we attached a strong magnet from RadioShack. A zoomed in view of the sensor and magnet can be seen in the following figure.
The placement of the magnet was important to get the maximum range of the sensor. Once all of these issues were solved we moved on to connecting the drumhead to the brackets. A final assembly of our device can be seen in the figure below.
Wood glue was used to finalize the assembly as well as dowel pins to attach a rigid rim to the base components. Another important issue to note is that we had planned on using FSRs to record when and where a drum strike would occur. After many trials we determined that these sensors would not be feasible to sense a strike. It occurs so rapidly that hits would only be recorded if you help it there for a few milliseconds, which would not be a realistic device. So after much discussion we decided to add another hall effect sensor at the center of the head and add magnets to each stick to sense each strike. A picture of our drumsticks with the added magnets can be seen in the figure below.
Similar to the idea of multiple FSRs discussed in our proposal there is room here to add multiple hall effects around the outside of drumhead. Unfortunately, due to the late recognition of our hall effect problem these added sensors were not added. To dampen the sound of a drum strike on the wooden board we decided to use a felt pad which you can see in the results section of our blog.
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