It’s robot design day! Today, we aimed to finalize a design for our robot. Before meeting, we had all individually come up with drawings for robots and subsystems, so we first looked at those and discussed our ideas.
One popular design was a clawbot with a vertical lift (like a scissor lift or arm). The claw attached to that would either be a standard grabbing claw or a side roller mechanism to intake the ball, which was an exciting idea. Either choice would allow for high precision at placing and removing balls, though it would limit speed and efficiency.
The other design was a snailbot, in which the ball is brought in through an intake, transported up with tread, then spit out horizontally out the top (the path is similar to the spiral of a snail shell). This design would allow us to efficiently score balls, and it offers the option of easily moving a ball at the bottom of a goal to the top (to claim ownership of the goal). However, it would also take more time to construct once our school and robotics lab reopened, which would most likely be already limited if we wanted to enter into any competitions.
Another idea involved a combination of the two, with an intake at the bottom and curved hood to direct the ball (like the snailbot design). Unlike a snailbot, though, it used an angled lift to push the ball up! This idea was very unique and sparked a lot of discussion, but we later abandoned this idea due to the complexity of the mechanisms and time it would take to try to build.
We also experimented with altering our drivetrain. One idea involved the diagonal thing, which would greatly increase our maneuverability. However, this might complicate aligning the robot to the goal when trying to score balls. Another proposal used an H-drive, which is like a normal drivetrain but includes a smaller powered wheel perpendicular to the rest that allows sideways motion! We were unsure of stability though, and wanted to make sure our robot couldn’t be pushed around easily. Additionally, none of our drivers have used this type of drivetrain before, so we thought sticking to something they were more comfortable with would be best.
Last season, in the Tower Takeover game, the 4008A team’s drivetrain only had two motors (the rest were used for the elevator lift). As a result, we found that during matches it was hard to play defensively, and we were pushed around quite a bit by stronger robots. Therefore, we wanted to make sure we had more power in the chassis this season. This priority for drive strength promoted several design features, such as using four motors, replacing omni wheels (which slide sideways when pushed) with standard wheels, and using four wheels rather than six.
After reviewing all our initial robot designs, we realized that we had a lot of differing ideas that could work. Therefore, we wanted to try to design two robots, although we understood that we would probably only be able to build one when we got back to the lab (if school campus opened up in time at all). To do this, we decided to split into two modified teams, which were different from the usual A and B teams due to new circumstances and availability. Team A decided to work on a snail bot design (which intakes the ball and transfers it upwards), while Team B would focus on a lift design (with a claw or tray that is raised up).
Each team then split up further by separating the main robot mechanisms (drivetrain, lift, intake, claw, etc.) for members to design. Although it’s not ideal and could lead to potential issues in the future, we decided that it was easier to each work on a separate part of our robots: since everyone is working remotely and we can’t meet up to collaborate, working individually might be more efficient. We’ll make sure to keep everyone updated at our meetings though!
Team A decided to build a snailbot. One member was in charge of the horizontal intake at the base of the robot. Her design mainly consisted of side rollers, in addition to their connection to the main robot (which, if possible, would be somewhat elastic, allowing the rollers to grip the ball while still easily rolling around it).
Meanwhile, another member worked on the chassis. They were in charge of the U drive that the team agreed on in addition to the chassis’ connections to other systems. Two other members also worked together for the vertical intake, which was the most complex subsystem. One created the back plate design, which involved creating a non-slip surface for the ball the travel on and the flipping curved hood to guide the ball once it reached the top. Lori worked on the front part, including the gears and tread roller. Although they are working on separate sections, we hope to get their two halves together sooner rather than later, in order to avoid large potential problems.
Team B is working on a scissor/claw robot. One member, focus on the chassis, which will be a U shaped chassis (although slightly shorter to accommodate the claw). Another member took the claw, which she designed around side rollers, which would be more efficient at picking up balls rather than a traditional claw due to its spherical nature.
Finally, another member worked on the lift. He decided to try a scissor lift due to its vertical motion (not vertical and horizontal like a six-bar) and general reliability. Although we had never made a scissor lift before, everyone collaborated to work out the details, such as how to power it and which pieces would work best. In the end, Zander settled on a design with one side of the lift anchored and the other moving horizontally. To do this, he used a linear motion bracket with a green outer slider that would run along a metal slider by a rack gear assembly on the top. The moving side would be powered by a motor, possibly more if necessary. Since the design included horizontal motion already, Zander wanted to try to add an alignment component that would slide out the front of the robot to line up with the base of the goal. This would increase stability and help the robot quickly score balls. However, this may not be possible depending on how the other parts of the robot are designed. This alignment piece would also affect the top of the lift. Again, one side would be anchored, while the other would slide with a similar mechanism to the bottom. If the alignment system was included, the back side of the lift would be anchored to allow the claw to extend forward (to make up for the robot moving back to align). However, if the alignment didn’t work out, then we would anchor the front side of the lift, which would maintain the claw’s horizontal position.
Next week, we hope to transfer our physical drawings into 3D digital designs! We’ve never tried CAD before, so we’re all super excited (but a little nervous too) to try it! We don’t have any software yet either, so we’ll have to research to find a VEX-compatible, user friendly, preferably free or low cost program. Stay tuned for more!
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