ScissorsLift vs. DoubleJointed Arm.

[Jonathan Norris]

Originally Posted by Joe_Widen

My team and I were having a debate, and for some reason there was a red flag shooting up in my mind whenever I hear scissor lift. I'm just trying to figure out what the red flag is....?

you are right whenever I hear scissor lift i see red flags in my head, they are unstable, uncontrollable, and not durable, oh and really really heavy. There really isn't and comparison between scissor lift and a double jointed arm, a properly designed double jointed arm wins. If created properly they can be very controllable and far more flexible than a scissor lift. If you are looking for a vertical moving arm look at an forklift (elevator) type system (111 in 2005 for example). I have only ever seen one, yes one, effective scissor lift.. and too many non-effective ones.

[Joel J]

Originally Posted by Joe_Widen

My team and I were having a debate, and for some reason there was a red flag shooting up in my mind whenever I hear scissor lift. I'm just trying to figure out what the red flag is....?

Maybe its that the best scissor lifts (beings used as an "arm") still ends up being garbage, and is still inferior to a mediocrely designed jointed arm.

[Cody Carey]

I have only ever seen one, yes one, effective scissor lift.. and too many non-effective ones.

These pictures are for you ... They are all "effective" scissor lifts. All that is needed to reveal a wealth of effective Ideas is a look into the past.
Some of what has been being said in this thread is nothing but a bunch of rash generalizations. If you look into Industry... you will see numerous instances of scissor lifts being used, because they are good at what they do. some mechanisms are better than others at certain tasks, It all depends on the application.
You can't just say: "Scissor lifts aren't good because they haven't been made to work yet. They will always be inferior. " It doesn't work that way.

Taken from HERE

Taken From HERE

[rees2001]

Originally Posted by Cody C

These pictures are for you ... They are all "effective" scissor lifts. All that is needed to reveal a wealth of effective Ideas is a look into the past.
Some of what has been being said in this thread is nothing but a bunch of rash generalizations. If you look into Industry... you will see numerous instances of scissor lifts being used, because they are good at what they do. some mechanisms are better than others at certain tasks, It all depends on the application.
You can't just say: "Scissor lifts aren't good because they haven't been made to work yet. They will always be inferior. " It doesn't work that way.

Taken from HERE

Taken From HERE

Funny you chose this picture... I was going to post how our team used a scissor lift in our rookie year and we found it easy to build and easy to use. It was fairly light & worked well enough. We connected across the joints with surgical tubing to give it that "spring" you talk about. The lift is still together but not attached to the base. Arms can be a challange.

[GaryVoshol]

Originally Posted by Cody C

These pictures are for you ... They are all "effective" scissor lifts. All that is needed to reveal a wealth of effective Ideas is a look into the past.
Some of what has been being said in this thread is nothing but a bunch of rash generalizations. If you look into Industry... you will see numerous instances of scissor lifts being used, because they are good at what they do. some mechanisms are better than others at certain tasks, It all depends on the application.
You can't just say: "Scissor lifts aren't good because they haven't been made to work yet. They will always be inferior. " It doesn't work that way.

//pictures snipped for space//

Taken From HERE

Wow, they let those go without pinch-point protection?

[Joe_Widen]

Yeh, the scissors lift would be primarily an arm. I think that Mr. Norris nailed it on the head. Maybe I just think that those red flags were more evident. Anyways, feel free to keep posting, I find this quite interesting.

[USAF Capt. Sean]

From what i can tell is that scissor lifts are more stable and can handle more weight. Plus the scissor lift can colapse down to under 10" and extend to over 90". by far this is way better then a double jointed arm.

[ggoldman]

The debate of arm vs scissor has two views:

Scissor Lift:

It is an inherantly more complex *Mechanism* since there are multiple sets of moving parts. If one small roller fails, the whole mechanism could be broken. That being said, the actuation of a scissor is simple in that it just takes a pneumatic cylinder or screw drive. Control is easier since it is a single input, but speed could be slower depending on actuation method.

Articulated Arm:

This is a simple *Mechanism* since there are only one or two moving parts involved. The control of an articulated arm poses a greater problem since you have to learn how to control different sections of the arm to create different motions. Sometimes, there are multiple positions of the arm that can get to the same point, so you need to plan on how you are going to move it.


In terms of strategy, simplicity, and usefullness, I would put my vote towards an articulated arm.

If our team has an arm, we will most likely do articulated.