I am researching using a cascade lift for Vex tower take over and I am not clear on how one actually works.
take a look at this animation
I wouldn’t reccomend a cascade lift for this seasons game - or any game for that matter. It isn’t “worse” than another lift such as a rd4b, but it takes a lot more effort to get it to work on a comparable level.
I’m trying to find out the same thing.
What are some of the pros of a rd4b
It moves straight up and down, gets pretty tall, and is relatively easy to build.
@Bman24 @Golf A rd4b will operate a lot smoother - the spacing necessary to get a cascade lift to work well takes a lot of effort, take a look at what 99371A had to do in orders to make theirs competitive enough to work against a rd4b:
In general, a rd4b will have less friction, be more stable, lighter, and less prone to failures. It will, with a decent and average amount of build quality for (i’m assuming - correct me if I’m wrong) your level of competition, have a LOT less friction and slop, and in general there are more teams who have researched it (and used it), for you to learn from. Both a cascade and a rd4b can reach the same heights, in roughly the same time, but only after a lot of tuning and ekeing out performance. At a lower level, a poorly made rd4b will beat out a poorly made cascade lift almost any day.
For the same amount of height, a cascade lift will use similar amounts of metal / aluminum, if you’re aiming to build it in a fashion similar to 99371A, where it requires 2 c-channels to build one stage, you have your two base towers, and your two moving trucks as each “stage”. A rd4b on the other hand, needs two towers, four arms, bracing, and then the midsection towers, and then 4 more arms to build the second stage. This rd4b however, will reach roughly the same height as (i think), three stages of cascade lift, not including the tower, which is going to be around 6 pieces of c-channel. Probably 3-wide, to make everything fit nicer. The rd4b can probably use halfcuts for much of the towers and bracing if it’s not carrying much weight. Then, you get to the chain that the cascade has to carry, and that adds up.
A cascade lift really only has the width of the tracks or “stages” to be stable, and as you near the top of the stages there’s less and less contact between the two trucks, which means that the slop that you’ll be getting is amplified a bunch - not to mention that you’ll need a bunch of bracing to keep stages stable that high up. A rd4b does also have issues, but bracing a rd4b is pretty simple, and there are a lot of good examples on youtube or elsewhere.
When there’s more instability, there will be more friction due to binding. This leads to the motors having to do more work, and thus slowing everything down. A rd4b is easy to make well, there are a lot of guides you can follow, and a little bit of slop will not be as terrible as a little bit of slop in a cascade lift.
there’s a lot of parts that can go wrong in a cascade lift - chain snapping, your stage holds breaking/bending, etc. A rd4b also has these issues, but there’s going to be a lot less of them if you follow a build guide or ask for help on the forums. A rd4b is also generally more open - you can easily access all of the parts and make changes to any portion of the lift without having to use a bunch of expletives. on a cascade - maybe not so much
I didn’t mention this earlier, but the way that the power is actually transferred to the lift is much more preferable in a rd4b - think about whiplash and the way shock works. In a badly tuned cascade, there’s going to be a lot of that, and it’ll likely result in operation which is not as smooth as it otherwise could be, and same for a rd4b - you’ll likely want to mount the motors in the midsection to reduce the slop you get - mounting the motors at the bottom and letting the power transfer up will amplify any issues with lean, slop, or imbalances that you have on the lift.
That’s all for now, if you have any more questions, please ask.
This past year for turning point, we had a cascade lift. It work alright. It was slow but very strong. It took a long time to build and get set to work properly. I would not recommend it. Not only does it take up a lot of room, they are very heavy and slow.
The way my robot is actually working out, I’m seriously considering a Cascade. But no leekz as to why from me. (Sorry.) Just know that it’s really space effecient for what it is, and, as stated above, is used in industrial forklifts for a reason. Albeit Vex is more about speed than strength and versatility.
This is not wrong, but a well-built and braced rd4b can also be pretty space efficient, and it just depends on where you need the space, and how you’ll use it (think about all the stacks that people got inside their rd4b in itz).
I hope you guys, whatever you make, get a great robot that can be an example for the rest of the community!
When an extension lift is cascade rigged, essentially the pulley or sprocket pulls the stages at the same time. Each stage of the lift will rise or lower in sync lwith each other. The lift will rise twice the speed of the previous stage, but lose half the torque of the previous stage for any additional stages
It works because magic
For some reason I feel like you don’t like cascade lifts…
Connect the bottom of the chain of the last section to the bottom of the next (not the chain) and the top of the last section to the top of the chain of the next, dm me for more details and pictures if u want