I’ve been wondering all year, but i have never really had the time to understand how teams get their ramp/tube holders to extend/pop out at the beginning of the match. I was wondering how your team’s ramp pops out at the beginning of the match. I need some in depth detail, because people have tried to explain it too me, but i don’t understand it exactly…
warning never implemented
my team was thinking about using linear slides attached to bottom of lexan so imagine
linear slide male
linear slide female
with a plate at the back attached to the the female linear slide
this would require very strong intake to push plate and linear slides but the weight of the linear slides would only have it extended when it was required and you wouldnt have an overly large mechanism sticking out the back when u didnt want it
you would also need strong arm to lift this
the way most teams do it from what i understand correct me if im wrong is have it attached on a hinge and when tension is released (ie rubber bands on the drive) it falls back
On our ramp extension, the ramp starts off folded up, but once we grab more than 4 objects the ramp will fall back.
For us, we used 2 screws to attach the pop out tray onto the back of our main tray. Then we used around 2 rubberbands on the bottom of each side of the flip out tray and the main tray to force it down. Then we put some standoffs and delrin bearings on our 6 bar lift and put rubberbands on that connected to a nut on the pop out tray to keep the tray down in the beginning of the match. Then when we lifted, the 6 bar would go farther apart from the flip out tray and activating around 18 in. Then the tray would stay put for the rest of the match due to the 4 rubberbands on the bottom.
P.S. Sorry for so many thens… I just like to use them when explaining stuff.
I did something similar but I cut a track in the polycarb (lexan) and used shoulder bolts, it slid out really easily but was a pain to make
We can show you all the details you need in our pits at worlds.
There’s string in a winch kit. You can tie one end to something fixed and one end to part fo the unfurled ramp. You can also move a trigger if it’s totally spring loaded. As you lift it will give that little tug to let the rubber bands take it the rest of the way. Or you could use the winch with a motor for what the kit was designed for and that tug will unfurl you.
The axis is just a screw on the c-channel and cut a bit to overlap nicely. Keep it loose with nylock nuts and you’re good to go. You could use shafts too but the screws work just fine.
Make sure you have a fulcrum/angle to get a vertical component of your force vector. Pulling totally horizontally does not work well. Just an inch or two or a 10 degree angle can be enough. Gravity and angles are your enemy. As the sine of an angle approaches 0, so does the vertical force component on it. So if you leave it at 10 to 15 degrees, that may be enough to open easily.
The unfortunate part of the unfurl is you have to expend the time to lift to get it to unfurl - a disadvantage in the skills runs sometimes depending on your strategy.
Also, don’t stand behind the robot - we had quite a few bopped heads and noses as we built and practiced.