Elevator vs. Telescope vs. Scissor

[Calvin_1631]

What do you prefer, an elevator, telescoping arm, or a scissor lift?

[Rich Ross]

What if it's none of them? Some teams (Spam for example) use arms with joints.

[brinsy625]

actually... the method i perfer is the one our team used...momentum and gravity

[Calvin_1631]

Dang, thats what I forgot. When adding the choices 3 seemed to little, thanks. OR A JOINTED ARM...

[LordTalps]

Well, we've actually got an elevated arm. With a joint on it.

Sooo...

[Kellen Hill]

We have a telescoping arm and while up in the air it sorta goes where it wants to. After attending St. Louis, the Jointed arm seemed to be a nice manipulator but other teams did really well with all of the other types of arm.

[lenergyrlah]

1731 has a jointed arm.

[Gabe]

604 has a jointed arm

We've got a 10 foot elevator that starts in the 4 foot category. It locks up, and has worked very very well for us.

[Guy Davidson]

Jointed arm with a roller based manipulator, with a forklift style arm coming second.

[=Martin=Taylor=]

I recognized early-on that telescoping arms and elevator style lifters would have an advantage this year since the rack is vertical and requires no "reaching." I think these are the best designs.

However, we decided not to use a lifter since they require more parts then an arm and are harder to build.

We have a lot of experience with arms, and we knew how to build one.

[Pavan Dave]

Last year I savaged parts from TeleScorpio and my mentor showed me how it worked. Since then, I have frowned upon telescoping arms, and for this game I do not feel it is efficient enough to use compared to the elevator, which many teams and robots have used including Chanizilla who has completed its tasks beautifully. As for scissor I am unsure of what you mean.

[Andrew Blair]

Scissors are very material instensive for their lifting ability. For a light game piece requiring quick actuation, a scissor is not the ideal way to go.

A telescoping lift is precise, stiff typically, and good for a heavier, more deliberate, reach type game. A good choice, but an elevator is probably the best choice here. In terms of material/fabrication costs, complexity, and speed, this is the winner. Quick, vertical actuation is easy, and cable is light. However, these elevators are typically quite flimsy at full extension. Not a huge deal with a 1lb tube, but still an issue that complicates scoring.

[Joe Johnson]

I have thought about scissor lifts a lot. They seem easy but in fact are quite difficult to implement successfully on FIRST robots. I was toying with the idea of lobbying FIRST to make a rule against them, but I think I have come up with another, better approach.

I think that FIRST should make a rule that explicitly allows scissor lifts but that requires that every scissor lift should have a clown head on top. The size of the clown head is dictated by the following formula:
Min Diameter of Clown Head = {Number of stages in the scissor Lift - (Number of Years Your teams has been involved in FIRST/4) } X 1ft.

Clown heads would be like bumpers in that they can extend beyond the normal limits of the robot, the associated weight is not counted during weigh in, and other robots can bash into it any time they like without pentalty.

While this rule is likely to be controversial, it would be extremely entertaining and I think that it help more people to see the difficulties of actually implementing scissor lift that is not laughable.

Joe J.

P.S. Heavy sarcasm alert.

[MrForbes]

I wonder what the 1726 bot could be described as? it has a motorized joint where the arm attatches to the robot at the "shoulder", and a latching joint at the "wrist", but it isn't really a jointed arm.

We'll see how it does in just a few days! should be fun. In solo practice the students could hang 5-6 ringers pretty easily in a 2 minute session.