There’s a saying in FRC that a drivetrain can’t win you a match, but it can sure as heck lose you one. I would argue the same could be said about your robot’s intake. You’re going to struggle to stack totes or shoot balls if you can’t pick one up.
So what makes a good intake?
Before I can answer that question, I need to get some definitions out of the way.
- Passive control – game piece is not in contact with any active component and can still move on it’s own
- EX: a gravity hopper
- Semi-active control – game piece is in contact with an active component but can still move on it’s own
- EX: hooper with agitator
- Active control – game piece is in contact with an active component and can’t move unless the active component moves
- EX: conveyor against a solid wall
A good intake will:
- Be in active control at the first moment of contact with a game piece
- This is really tough to do with a clapper intake, unless the game piece and robot end up in the same position every time, like feeding from a human player station
- Roller intakes do this well and spinny things are easy to make
- Be wide to make it easy for the driver
- Never lose active control of the game piece
- Depending on how the game piece moves through the robot, you can have “dead spots” where the game piece isn’t held against an active component
- Some teams will add a “kicker bar” that deploys with the intake that sits just below the bumper to prevent the ball from getting stuck
- ***this is negative for catapult and plunger shooters, it’s difficult to design them to not lose active control right before they fire
- Deploy/retract in a repeatable way
- An intake that stays out all the time is likely to get hit and draw penalties so it must retract back inside the frame perimeter
- Have a hard stop on the way out to make sure the intake ends in the same position every time
- Pneumatics can make this easier
What are the steps to making an intake?
- Prototype to figure out the following: (***these things are hard to measure so take lots of videos of each trial)
- Crush: how much do you want to squeeze the game piece (or if the game piece is hard, how much the wheels should crush)
- Wheel/roller type: test a bunch of different materials to see what does/doesn’t work.
- Wheel speed: how fast do your rollers need to go to get the game piece from ground to inside the robot in under a second?
- How far away from the bumper should the first roller be?
- Do we need a kick bar?
- https://photos.spectrum3847.org/2022-FRC-1/2022-Build-Season-1/Week-2/i-PkC2zsL/A
- Make a sketch
- Figure out where rollers will need to go to maintain crush and active control
- Where is the motor going to be placed that it isn’t in the way of the game piece?
- How will it go from fully inside the frame perimeter to outside the robot?
- Review it!
- Grab a team mate and mentor to look at your sketch to catch issues before you get to far
- Select your materials (Needs to be able to take a hit!)
- Want it to flexible and light weight? Use Lexan
- Want it to be strong and withstand your driver running it into a wall? Use 1/8″ aluminum tube (see 2056’s robots, they’re built like tanks)
- Lots of options here, if unsure, talk to a mentor for advice
- Design it
- Look at past designs, make sure you include all the bearings, and spacers you’re going to need
- Think about how wheels and rollers are going to stay in place
- Review it
- Grab a team mate and a mentor to look over your design to try and find any obvious things that are missing
- Make it! And expect to have to make it a couple more times
- No design is ever going to be perfect, but it doesn’t have to be. You’ll learn way more from putting it in the real world vs keeping it on a computer screen
Every subsystem on a robot is critical to success, but your intake is your first point of contact with a game piece and is likely the system that is going to need the most tries to get right.
Hope you found this useful! If you have any questions or things that I missed, reply and let me know! Have a great day!!!