Forgive me if this topic has been covered before; I couldn’t find anything in the forums or through a quick google search, so, here I am. The question is simple: what style of lift, such as scissor or n-bar (4 bar, 6 bar, etc.), gives the most lifted height for the smallest starting height. If I’m unclear: say you have a bot in the 18" cube. What is the tallest you could expand, and with what type of lift?
Not intended to be used in competition; I’m mostly curious.
RD8B
its either a multi stage scissor lift or a multi stage elevator… I think the elevator
Elevator. RD4B was a joke
Only double? Would there be any inherent drawbacks of using as many layers as space permits? (other than friction) This would seem far better than a layered scissor lift though; each layer on a scissor lift would lose height. The optimal design I take it would be a reverse n-le n-bar.
Forgive me, I typed up my previous post before you responded. After some extra thought, I’d rule out the scissor, especially is more than one stage is present. (scissor nested inside of scissor)
Aww, I thought you were serious 
The max reverse I can see happening that works fine is a sextuple reverse 8 bar, but with size constraints, the highest you can get while staying in the size limit is by making a multi-stage elevator
i think a scissor lift with multiple stages would easily be the most efficient on paper, as for the real world, an elevator or a double 3 stage four bar would be good.
Even though I don’t like these types of lifts, I may have to go with a scissor lift. If you were to build a robot designed like in this video if its’ lift when in the down position is built to the 18" height, it will go very high.
If what I’m saying makes sense…
Scissor Lift has the best compact:expansion ratio of them all. However lacks non-lateral torque and prone to flex and sway problems after a certain height.
That is true, but rubber bands can fix the torque issue, while having potentiometers on the right and left side and program an auto-alignments program should make the lift be more parallel on both sides. But I don’t recommend such work when you have other, easier, and more durable types of lifts.
danny lift
I meant non-lateral torque meaning it can’t pull itself on an angle very well without breaking making hanging for this season a bit harder with a scissor lift.
OP asked solely for the most space efficient lift design, which would be scissor lift. If one is searching for a space efficient AND practical lift design, then RD4B or RD6B should do just fine. 6+ feet should be enough, right? 
Somewhat related tangent: what is the highest possible height a vex legal robot (18in^3, cortex+battery, 12 motors) could reach?
If it doesn’t contain a drive, or at least a two motor drive, I’m assuming it could be about 15 to 30 feet (If you contain anti-tips to have a wider base).
Well in the most extreme of situations…
A robot could have a one-time “lift” that expands at the beginning of the match; it would basically consist of only vertical linear slides that expand upwards into a massive tower. That would probably get you up to a 100 feet if you built it right.
So, I suppose it doesn’t need an intake or drivebase. Anti-tips would be needed, but aside from that, I’m simply looking for a lift that can go both up and down, fit initial inside an 18" cube, etc. You’re welcome to go crazy; I’m mostly looking for a tower, as long as it doesn’t fall over or break parts.