Hello, I am wondering what people prefer doing for getting rings out of the corner. Bots with wide drivetrains can have difficulty moving rings out of the corner to put in the mobile goal. Do people prefer a manipulator using pistons or a specially shaped intake for the corner.
A mechanism I saw from 393V (Legacy Venom) used a piston connected to a “hand” that when expanded, pushes the rings out of the corner, if you want to make something similar, use plastic instead of a big metal plate
Many use a doinker mech, a pneumatic, sometimes motor powered bar at the front with a bit at the end which can be also be used to grab, move and flip mobile goals. They usually put an extra part (like polycarbonate for example) on the top so that they can move rings more efficiently.
4 Likes
Usually called a “doinker” mech, its a horizontal expansion (usually pneumatic powered) that flips out to the front.
(Image credits to FUN Robotics and 2796V)
6 Likes
At my last competition, the head ref ruled doinkers illegal if used to move the rings on the inside of your bot because you are manipulating more than two with a concave surface. What are your guys’ thoughts on this and what other ways are there to reliably remove corner rings with a wide bot?
I know that you can have a bent piece of polycarbonate above the intake and could get a bottom ring in a stack of two so you could apply that to the corner I just don’t how good that’ll work but there’s a chance it could!
I’m not sure there is an effective and legal way to do a manipulator so I will try a specially shaped intake. Last tournament the wheel intake did not stick out enough to get to the corner and the drivetrain hit the wall. If I can find a legal manipulator design I will definitely try.
Most doinkers I see are just high strength shafts with a piece of polycarb on the end to reach the whole stack. If the polycarb is curved, then yeah manipulation of more than 2 rings would be illegal.
Legality is a bit iffy here, but here is a rough explanation:
(Assuming the doinker mech is straight and not concave, and the robot is possessing 2 rings in their intake)
The two left cases are legal, since the robot is manipulating the objects with a flat, non-concave surface of the robot (and hence would be plowing). However, as soon as the ring slides into that “pocket”, the robot is using a concave/more than 2 sides to manipulate the objects, which would not be plowing (and hence would be possession and illegal).
3 Likes
Thank you for the diagram, what I can do to keep it from coming in contact with the bot and being considered concave is this design I have made with a wedge that when driven forwards should be able to hit the rings out of the corner.
1 Like
The two areas highlighted in blue would be considered concave. So if the rings go into there, that would be considered possession.
However, depending on how big the wedge is, the top blue area might not be considered possession by the head refs (if it’s really small it may be negligible, but this is up to the head ref).
Just to be safe, I would either make the wedge’s horizontal profile really small, or make your doinker mech shaped like the red outline below:
2 Likes
The manipulator in my design wont be swinging but instead when it hits the stack going fast(drivetrain) it will launch it to the side. But I should definitely fill in the red area like you said.
Another thing I’ve seen teams do is make it so that the doinker only contacts 2 rings so that its only 2 ring possesion.
that is what we do, ours contacts the middle two so that the top ring falls out of the corner. it works well.