Our machine was the Bio Rad Model 1325 Econo-Recorder. It is part of Bio Rad’s Automated Econo System, which is used for chromatography. This part of the system is an optional and “output[s] the analog data signal, pen drop, and paper feed command to the recorder,” according to the instruction manual.
From observing the external features, we can see it has an outer plastic casing and knobs/switches under a plastic covering that hinges open, all of which are specifically manufactured for this device. The plastic covering closes using a snap joint, and the outer casing is attached with screws.
One of our first realizations is that this device is battery powered, which makes it more accessible for use in lab settings that may not have reliable electrical power. We also noticed a replacement fuse (annotated in red) inside the battery compartment, indicating that the device is meant to be opened up and fixed if damaged.
We began opening the main component of the machine by unscrewing the plastic casing and unplugging internal wires.
We noticed that once the large outer casing was unscrewed, many other components came off easily, again indicating the machine is intended to be opened and repaired.
We unscrewed the PCB to find another underneath supported by stand-offs (circled in red). The gray ones are likely off-the-shelf, but the white ones are part of the outer casing, which was injection-molded specifically for this machine. The white stand-offs go through holes in the PCB (circled in blue), indicating the PCB was also specifically manufactured for this machine, not just purchased commercially. This is also evidenced by the fact that the user switches (which are very intuitively designed) connect directly to switches on the PCB (circled in yellow).
On the bottom PCB, we found the fuse (circled in red) that is meant to be replaced by the extra one in the battery compartment. Though we realized the machine is meant to be opened up, we hadn’t realized to what extent. We now see it really is meant to be taken fully apart if needed.
The rest of the disassembly was fairly simple, consisting of more unscrewing and unplugging.
We reached the final internal compartment, which housed a pulley system powered by a DC motor (circled in red). These components were a little bit harder to take apart, some even requiring a drill to unscrew. This, combined with the fact that they are housed separately, indicates it may not be intended to be taken apart.
After weighing all the components, we came up with these values. In total, the components weighed just over 2kg, making it a compact and relatively light-weight lab machine. The heaviest component was the outer plastic casing, at more than half of the total weight. The designers may have had to balance portability with durability with this part. Given the diverse and specific make-up of all the components, this device likely isn’t meant to be recycled.
Our worksheets can be found here, where we cataloged some key components and design elements, all of which are mentioned in the post above. Our clean work station is below.
As a first-year PhD student hoping to develop a medical device as part of my thesis work, this assignment was very informative in learning about design choices that can impact useability, sustainability, and longevity of the device. Importantly, I learned to consider the use-cases of the device, whether a user may need to take apart the device, and how to incorporate that into the design. I hope to take these lessons throughout my PhD and beyond!
