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Robot Overview
Robot Overview
The 2018 season brought around many changes on the Spartan Robotics team. This is the team’s tenth year competing in FIRST robotics, and the team decided on completely updating their design process for their 10th anniversary. Atlas was designed entirely on Autodesk Fusion 360 by students. With the abundant capabilities of Fusion 360, the students were able to tackle the Computer Aided Design and Computer Aided Milling (CAD/CAM) process on one software platform. Listed below are the different subsections that compile the entire robot.
Full robot renderings were completed in Autodesk Fusion 360.
The team’s mecanum drive was powered with the standard four CIM motors, but used 5.95:1 ratios in the four independent gearboxes. The strafe feature also allowed the team to align themselves with the cubes on a more direct path.
Drive train
Drive train
Another first for the team this year was the implementation of mecanum wheels. The team collectively decided that being able to maneuver the field efficiently was key to in-taking and scoring power cubes. A mecanum wheel is powered by a single gearbox, and has poly carbonate rollers on the wheels at specific angles. These rollers allow the wheels to slide linearly and also rotate normally like they would on a car.
Testing mecanum drive.
Intake
Intake
The team decided to design a wheeled intake to allow control over the power cubes during the match. Over the design phase, there were five different iterations of the intake/ mounting combination. The fifth iteration, pictured to the right, weights only 9.7lbs, which is five pounds lighter than the original design. The motors used to power the four inch compliant wheels are 775 pros from West Coast Products. These motors were geared down using a 12 tooth to 36 tooth pulley system, allowing for a 3:1 reduction at the output shaft. Additionally, the wheels are able to linearly slide relative to the motors. This allows for alternate cube orientation.
Honeycomb patterns allow for maximum strength while removing excess weight.
The final iteration of the intake system.
Intake 4.0 is pictured above.
Depicted above is the superstructure on the 2018 robot at the Greater Pittsburgh Regional Event.
Superstructure
Superstructure
The superstructure for the 2018 robot is comprised of 1” x 1” x 48” 5052 aluminum tubing joined together by smaller support beams. The superstructure provides support for the lift mechanism, and also houses the electronics board and pneumatic system. The superstructure was designed with a versatile hole pattern, much like the VexPro VersaFrame. The students designed this hole pattern in Fusion 360 to allow for quick changes and the ability to reposition components if needed. The large 48” beams were graciously machined by Alle-Kiski Industries on a Haas CNC mill. The smaller support beams were machined in-house on the Spartan’s Tormach CNC mill.
Thank you Alle-Kiski Industries!
Assembling the individual beams into the framing of the superstructure.
Lift
Lift
Perhaps the most complex subsystem on the robot this year was the lift mechanism. The lift is run off of one CIM motor with a 50:1 gear reduction that outputs 136N of torque. The lift is a two stage lift that runs off of one continuous chain. The first stage of the lift (the intakes), rise 48 inches on the first stage and then reaches the hard stop. The second stage of the lift is then engaged and rises another 38 inches. The team prototyped multiple iterations of gearboxes that would be needed to lift the intakes and second stage. There were three different iterations of motors and gearboxes that we used to power the lift. The team also utilized new stress-analysis software powered by Autodesk to ensure the gearbox plates would not buckle or warp under extreme load.
CIM motor with custom gear train powering the lift. (second iteration).
Lift in action.
Scoring points by depositing cubes in the switch.
Initial Rendering in Fusion 360
Adding extra rivets to the slides at the Greater Pittsburgh Regional.
Stress testing in Fusion 360.
Electronics
Electronics
There were some changes from previous years in terms of the electronics on the 2018 robot. The drive motors were wired to Talon SRX speed controllers via the CAN Bus system, as opposed to PWM that was used in the previous years. The CAN system proved to run the drive motors smoother than the PWM system. The secondary motors were wired to Spark motor controllers, which were controlled through PWM. The drivers opted for a two-controller setup this year, in order to delegate specific tasks to each driver. Quaduacore encoders were used to measure the distance traveled by the robot in autonomous mode.
Pictured above is one of the team's final qualification matches.
Mechanical Binder.pdfAbove is the material that the team provided to the judges in order to help fully explain our design and the processes we chose to bring our concepts to reality.
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