In the take-apart lab, the device we worked on was a printer; the Brother hl-l2320d, which is a discontinued laser printer. Before taking apart the printer, we brought several Phillips screwdrivers, flathead screwdrivers, pliers, wrenches, and scissors to the workbench. However, we ended up using only the screwdrivers for the entire disassembly process. As soon as we got the printer we dove straight in with our screwdrivers, without attempting to see if any parts would detach without removing any screws. At the start of the take-apart lab, we did not strategize. In retrospect, we could have removed the paper tray and powder cartridge without using any tools. While we did remove some screws that were visible to us from the get-go, we were unable to detach the outer panels from the main body. When we were frustrated and stuck, Dr. Wettergreen showed us how to detach the side panels using a flathead screwdriver to push back some tabs holding the shell in place. We were unaware the printer had a locking mechanism to keep its parts secured. The machine was essentially assembled using the locking mechanism and Phillips screws. With this newfound knowledge, our disassembly process became much smoother.

Once the side panels came off, we saw the main board with several connections to the other parts of the printer and the gear system on the left side. On the right side, we saw the power supply unit with an external cord and a fan.

At this point, we removed the powder cartridge and the paper tray from the main body. With the side panels separated and the powder cartridge and paper tray removed, many more screws and tabs held by locking mechanisms became visible. We simply unscrewed all the screws and pushed back all the locks we could see. Then we pulled out that top outer casing as well. On the left side, we pulled out the gears and the motherboard. Further disassembling the right side of the printer, we took out the power supply, 2 PCBs, and the fan. We then worked on disassembling the fuser unit in the front. The pressure roller in the fuser unit had a spongy texture, we initially thought it was some sort of mechanism to rotate the paper in the printer, till we looked it up.

We removed the laser unit from the main body from the top, and disassembled it further, which revealed a translucent plastic structure.

We were also able to separate the keypad input area of the printer from the main body, and separate the silicone outer covering from the PCB.

 

At this point, we had disassembled most of the huge chunks from the printer and our table looked pretty messy. To be honest, at this point, everything was pretty overwhelming. Especially as, at the time of the take-apart lab, we did not have any insights into what the actual parts did. So nothing made sense. It is only now as we did our research to write a blog post that so much of the process makes sense.

Now we worked on separating all the pieces of metal and plastic from each other in the main core of the printer body. We noted that the type of plastic used throughout the printer differed greatly.  The gears and most of the plastic inside were quite rigid and non-malleable. The only plastics that bend without snapping were the plastics used in the paper inserter and the plastic parts used as a locking mechanism. For such a huge printer, there were far fewer screws than expected, probably due to the use of the locking mechanism throughout the printer. Considering the amount of plastic and metal that had unique shapes and were held together with the locking mechanism, they were probably uniquely machined to build the product. It is possible that the powder cartridge, fuser unit, and PCBs were off the shelf.

 

Categorization of items

When we successfully took apart the printer, we categorized each of the parts in the following categories: screws, gears, springs, power (potentially combine with electrical), electrical (communication) system, PCB cover, fan, lenses, mirrors, spring within a glass/reed switch, custom connectors, plastic (inner pieces), metal plates and washers, housing, flexible inner components (system that holds the paper), buttons, cartridge and feed rollers. In terms of parts, the most present in the printer were the screws, we counted 86 and the heaviest part of the printer were the plastic inner pieces which were 1900g. In comparison, there were larger pieces, and we counted one of each for example the power wire, fan, buttons, and cartridge. The lightest item we measured was the PCB cover at 7g. In retrospect, the machine was not put together in a way that allows us to easily reassemble it if we take it apart completely. The first few items that were removed: left, right, and top outer casing, powder cartridge, fuser unit, laser unit, and paper tray, were probably designed to allow people to easily remove and reassemble it if required, possibly to allow people to fix these components if something went wrong. But once you start removing components that are deeper in, it becomes more complicated to disassemble them, I would assume those pieces are not meant to be taken apart.

When thinking about the design of the printer and all of its components, we came to realization that some parts of the printer can be recycled. Some parts that can be recycled are: ink and toner cartriges (companies usually have recycling programs where you can return the used cartriges), plastic casing, metal components, electronic components (may contain gold, silver, and copper) and the cables.

Finally, this assignment was fun and interesting as it showed us how an everyday object like a printer is built. The most surprising things we observed are the amount of screws and special locks we had to undo to open up the printer. We learned that the the printer on first look may seem like a simple machine, however, there is a more complex system that allows for the paper to be taken, ink to be applied and achieve the final product. We were also able to identify parts that we could not take apart and question them, which unleashed our engineering thinking.

https://docs.google.com/spreadsheets/d/1qjupBRDosH5IaqZzzr-hjSFbAkl3iTaq/edit?usp=sharing&ouid=113650325712484586980&rtpof=true&sd=true

https://www.brother-usa.com/products/hll2320d?srsltid=AfmBOoqZZ6iSPli7CI6mfYNN2z-NmsxHESR3YVxq_J98dcT7fo0tyGKq

 

Clean up TIME!