Dual leveled cylinders

[MNov]

Are we allowed to use them?

[Tristan Lall]

If you mean cylinders with intermediate positions (e.g. three-position cylinders), then no.

If you mean two-segment telescopic cylinders, then no.

In fact, if it's not a cylinder that meets <R89>, and is therefore identical (down to the part number) to a cylinder on the Free Pneumatic Components Order Form, it's not legal. There is one exception, because your team is located outside North America: you may ask FIRST for an exemption, by following the procedure in <R42>. They will only allow parts with the same function, but may permit slightly different dimensions, or different manufacturers.

[MrForbes]

But I don't think there's any rule that prohibits you from making your mechanism in a way that allows you to have the cylinder operate in 3 different positions at different times. For example, we are considering making a tilting fork lift (not a sliding type you normally think of), that would start our all the way up and back, then tilt all the way down, then when it tilts back up a bar would have dropped in the return path so it would end up not as far back as it started out. The bar would be reset before each match. This would allow us to have the robot fit in the inspection box and still allow the mechanism to clear the ball when it's being used.

Also we are planning on having a catapult that uses the cylinders in a way that they are not fully retracted, but the mechanism is latched down, and they can store energy in the cylinder this way, and when the mechanism is released they can shoot the ball.

And for the gizmo that knocks the ball down, we might use the same trick as on the fork, that is have it start out stowed parallel to the floor so it's less than 60" tall, then use a cylinder to pop it up so it's vertical to push the ball off, then have it tilt back down (against a gravity activated stop) only enough to clear the overpass, and still leave room in front of it to allow the ball that is being launched to leave the robot.

[JesseK]

You can have 2 separate cyllinders that are linked serially together. We've considered this several times but are ruling it out each time for options that use less weight or are more stable/less likely to break.