robot

i just updated our limit switch arm because it ended up snapping!! i thickened the arm and i also included a filleted part to prevent it from snapping so easily. that’s it for today!!

i finally have a good idea on how to slice for bambu printers!! i did a lot of 3d printing today, and i started by reprinting the side funnel walls . i also helped to make an attachment so that the limit switch would be pressed once the intake has pivoted past a certain point, to make sure it doesn’t touch the ground. it is definitely not the best solution but i was able to make it work with a bunch of tape and 3d print iterations !!

we finally got our intake and shooter to work! i mostly helped by tensioning the neoprene rubber strips and using rubber glue to secure it. earlier, i was trying to make a 3d print to make it easier to cut the rubber strip so that it can be cut at an angle, allowing me to overlap the rubber without making the conveyor too thick. however, that didn’t end up working because the rubber was difficult to cut, so we just decided to glue one on top of the other. one issue we ran into was that on the overlapped portion, it would jam into the pulley for the shooter. this was eventually fixed by cutting the part of the rubber conveyor that was too thick and would hit the pulley! with the extra scraps of rubber that i messed up on, i made a little dude with scissors

i had to take apart and reassemble the intake because the pulleys were on the wrong side… since the pulley on the motor shaft doesn’t fit over the set screw on the shaft, the final belt had to be on the opposite side, so i had to take everything apart :’) my teammate attached the shooter system onto the intake after i was done, so our robot is finally coming together!!

i worked on assembling the intake, which was mostly the last part of the day today. we got our metal parts in the afternoon ish, so earlier in the day i was working on the guides to funnel the balls into the intake. i also continued refining the cad so now it looks like this!! the intake itself is working decently okay, i have to attach the motor tomorrow. one problem is that i have to wrap around the rubber onto the conveyor, otherwise there is no contact from the rollers on the conveyor to the tennis balls.

on friday and today, i mounted the 3d prints to the shafts to start assembling the intake. i was struggling to attach a lot of these parts to the shafts because a layer of the prints kept on stopping the shaft from going all the way through. someone else had to hammer the parts onto the shafts in order for it to work :’) we’re still waiting on our metal part that will contain all of our intake parts, but we do have other components printed. our rollers were printed using TPU, and we also got our pulleys and shaft collars finished as well. we also have very very colorful filament now!!

yesterday i worked on making the shaft collars and pulleys to print out. our pulley prints were not very successful, but the shaft collars turned out great. i downloaded a free shaft collar file from this link and i changed the size of the screw hole, the width, and i adjusted it so there were two flat ends (so we could use a screw and nut). my team also cut the shafts so we can start making our intake

today i iterated more on the design of the intake. after printing the pulleys, we realized the belt was slipping and skipping teeth on the pulleys because we were using GT2 belts. we’re now pivoting to HTD-5M belts so we can hopefully not have any slipping happen on our intake. we also ordered more parts and added them to our purchase list!! when the sheet metal comes, we will be able to test the fit of bearings and other parts as well.

here’s an update on what the robot has been doing! i haven’t been working much on the driving part, so my teammates did a majority of figuring out how to navigate the course and how to drive. our robot was able to make it over the hill (but it flipped over if you watch the video lol). i am still working on the intake, but i have gotten further by printing out some pulleys and some shaft to bearing attachments we might use on the robot. tomorrow we will hopefully order sheet metal to hold our intake system. also, one of our prints turned into a blob

some of our parts for the intake arrived, so i was able to design more parts of our intake around it. i adjusted the rollers and came up with two different iterations, depending on the width of the rubber we will use to wrap around the rollers. i also measured the diameter of the hex shafts that arrived, which let me test printing out GT2 gears. i edited the gear by finding a part on McMaster-Carr and cutting out the hex shape and chopping off the extruded portion.

i worked on our shooter design, coming up with different ways to get the tennis balls into a bucket while fitting into our size constraints. especially with having a pivot on our intake, having the motors for the flywheels in the back would add too much weight, so i am still figuring out how to get that to work. i am testing out different orientations for the motors and flywheel, such as a dual horizontal flywheel shooter and a single flywheel shooter.

today, i worked on editing our parts that will be machined for our intake. instead of making it three pieces, we realized we could just bend one large piece of metal. for the motor mount, i added a way to allow it to tension so that when we add belts, we can adjust accordingly. i also ordered all the parts we need for the intake system, including the shafts, motor, bearings, etc. lastly, we also started planning out how our shooter would work, which we chose to do two flywheels at the end of the conveyor.

i mostly researched different parts to purchase and further refined how the intake would work. to run the conveyor, one motor would power the first roller, then the rest would be connected by pulleys and belts. i also added a motor mount to the side plate of the intake. for the chassis itself, i extended the base plate and L-brackets so that it would be 15x15 inches, which was one of the constraints.

yesterday i worked on combining our intake system with a pivot. i realized that there was very little space between both motors, so i moved the pivot between where two motors are, where a shaft would be placed under the intake. however, in order to fit under the 8 inch limit, the pvc pipes would have to be smaller or the walls of the intake would have to be shorter. i also started putting other components into the CAD, including the bearings, pipes, and pulleys that might be on the robot. lastly, i tried to modify the bottom pan of the robot’s frame to allow for the intake to turn downwards at a more drastic angle.

today, my teammates and i first worked on getting the 3d printed center parts of our wheels to fit. the pneumatic wheels were really difficult to work with, especially because the prints weren’t fitting on perfectly (it took us like 1-2 hours). while the others worked on driving with the new wheels and drafting the climbing mechanism, i worked on designing our intake and shooter. i made a 3d model and a geometry sketch to figure out how the pivot would work and how our motors would be mounted. i eventually landed on this design that i will edit more tomorrow.

i continued to work on the intake system, which we plan to do a roller and conveyor system to hold/intake the tennis balls. i found several components online and compiled them into a spreadsheet to check the costs. i ran into some issues, especially with figuring out how to pivot the entire conveyor while being able to secure the two plates so they move together.

earlier in the day, we switched out our ESCs so now our wheels can turn in both directions. we also tried flipping over the robot to see if that would allow for a greater chassis to wheel clearance. later, we brainstormed the next steps for our robot, especially the intake and shooter as well as the climb mechanism. i spent a lot of time creating geometry sketches for different ways we can shoot the tennis balls to fit within the size constraints. we ended up choosing to do a conveyor-like system and either magnets or a cascading system for climb.

we assembled all of our aluminum parts using rivets and tested our drive program. our wheels started to fall off because the 3d prints started to get looser on the motors, but we were able to successfully drive. although we only used our unidirectional ESCs, we were able to drive around by only going forward. the bearing pivot had issues as well, especially because when it rammed into cinderblocks it would get bent… but we were able to print containers for our electrical components (batteries, raspberry pi, arducam etc.). i was able to test my vision program to slalom around the cones, and it wasn’t exactly perfect but it was able to respond to obstacles.

after we 3d printed more wheels and glued rubber to the pla, we got to assemble our first iteration of our robot!! we used a cardboard box temporarily, but it was very flimsy so the motors/wheels weren’t very secure. right now, we are using unidirectional ESCs so we will hopefully get bidirectional ones so our robot can go backwards. i used ai to work on a vision program so that the robot would slalom around the red cones using the raspberry pi and arducam. also, our aluminum parts finally came in so tomorrow we will get to put together more parts

as a team we worked on figuring out the cad for our robot. i worked on making the l-brackets using onshape. we took inspiration from the hammerhead gobilda robot that had the front two wheels on an axle which would help us when navigating the obstacles on the course. i learned how to use new features on onshape, like the sheet metal model and the flange to make bends on the model.

we started brainstorming ideas for how our autonomous robot would look like and function. since our first goal is to just have a robot that can drive, we sketched out a drivebase and chassis. we also researched different materials, like motors, that we may need for the project. earlier, i used ai to develop a vision system on my computer to detect tennis balls.