Hi CD, our team is using a chain driven cascading elevator system to transport cubes up and down, and the middle stage looks like a long H. Our intake is connected to the cross-bar of the H by two hinges. We currently pivot the intake (to shoot and/or start in or return to our initial configuration for the start and endgame) with a 775 pro on a 700 something to one gear ratio, the shaft of which drives one gear that drive a gear hard mounted to the plate on the intake where our pistons are mounted. The problem with it is that we have to cut a gap in the second stage (the H where the 775 is mounted) to allow room for the gears, and no matter how much we reinforce that gap and that second stage something ends up bending to make the gear teeth slip out of meshing well enough for it to work. We plan to remake the cross-part of the “H” to avoid the gap problem, but we now are trying to find a better idea to make it pivot. Any ideas are welcome, thanks for any help.
Our team has a very similar concept, except instead of pivoting our cascade lift we have it on a linear track. At the start of our match a 775 pro is use to hold the lift back. We then have a Vulcan spring that we use to bring the lift forward.
We don’t actually pivot the whole elevator, it sits right near the edge of the frame and we have to pivot our intake to be inside frame perimeter in the beginning. The pivoting mechanism is currently mounted to the second stage to get it to fold into the second stage.
A picture of this would be very helpful!
Here is a link to some pictures of it: https://imgur.com/a/RIqNe
You’re going to want to re-enforce the horizontal faces of the cross-bar of your “H.”
Imagine an I-beam. The reason they’re so strong is because they have a high moment of inertia and are very good at resisting bending under vertical loading.
You’ve taken something close to an I-beam (square channel is almost like two I’s stuck together: II) Your strength still comes from the two horizontal surfaces, however you’ve cut out a big C, turning it to only a vertical face (l) in the middle.
The best thing would be to bolt some Al (or steel) flat bars to the bottom and top of your cross-bar to span the cut-out you’ve made to give it back the I-beam-like properties
Ditto what Raul said. You’ve taken a piece of square tube, and cut a notch in it in such a way that your four-faces of strength are now down to one, and one that’s at a mechanical disadvantage to boot.
Likely what you’ll need to do is somehow create a bracket that mounts to that square tube and goes above the gear to tie the top of the tube together, but that might run into clearance problems with the bracket that actually lifts the intake itself. If you’re already in the process of redesigning it so you no longer have the notch, go for it.
Thanks to everyone for the responses, after doing some thinking we have decided to for sure replace the bar that has a gap in it with a complete bar for structural and reinforcing purposes, and to work around this now we are planning to build a linkage that goes over the bar. Though we haven’t had a ton of experience working with linkages I found a great software called “Linkage” that has been a great help in designing how it could move to stay within the space we have so I think it will most likely be able to work. Nuclear worst case is still just give up on the tilt and ditch out climbing hardware, but we really want to make this work somehow. If anyone else still has ideas please let me know.
From your Blue Alliance picture it looks like you have pneumatics on your robot. If don’t need variable angles (only down for regular play and up for starting config and endgame) you could replace the gearbox and motor with an air cylinder. Its hard to tell how much space you have but you could try replacing the gear on the intake with a sprocket using an air cylinder to pull the chain.
Thanks to everyone who offereed responses, after a solid week of work on our withheld elements we have been able to successfully create a variably angling intake with the use of a linkage and we were even able to lose half a pound in the process! We are now in great shape for our comp this weekend!