Varun’s Status Report for 2/17/24

This week, I focused quite a lot on designing the suction system for our robot and finalizing the robot arm. On Monday, I showed Prof Mukherjee a conceptual version of our robot arm, but upon further re-evaluation, I decided that it would be better if I designed it in a much more modular fashion. I designed modules for our torque servos and the non-torque servo (that controls the suction cups) in a way that could interface well with the previous design, so that not much change needed to be made. Here is the final design of the end effector movement Robot Arm:
 
The design of the arm, though it looks quite complicated, did not take nearly as much time as the conceptualization of the suction mechanism. On Monday, I showed Prof Mukherjee the mold that I had spent time designing to create the requisite suction for our project. When I tried to use some silicone resin to actually fill in the mold, I made a mess, and once it actually dried, nothing came out of the mold. I either hadn’t designed it correctly, or my process for transferring the resin was incorrect. Either way, when I came back to it on Tuesday to try and get the mold, I realized that the process of iteration for this would be unnecessary and tedious. The solution? Money. I scoped out a relatively cheap silicon bellows suction cup that would allow us to conform to the shape of the object we want to pick up, and I found one on Amazon that would work.
 
Pictured above are some of the pressure calculations. With this in mind, though the syringe could definitely generate enough pressure for the task at hand, I realized that we may want to use multiple suction cups. To generate enough pressure, I need a bigger syringe, and with a limited amount of real-estate on our Rover, I needed a better solution, so I found some DC air pumps that will do the job well.
Some more time was also spent on trying to figure out how to interface with the silicone. The cups I found interface with an M5 thread, and the DC pump can connect to 4 mm tubing. I found an interface between tubing and threads that fit the aforementioned numbers, and we’ll buy those on Monday!
My progress is a bit behind in my eyes, but we have a large overall goal to finish assembly by March, and I still think that is possible. From here, I will spend time to 3D print parts and ensure that we can get our hands on our physical material as soon as possible.