Scissor Lifter?

[ShinyShips]

There are only two rules when designing on our team:

1. No turntables
2. No scissorlifts

I haven't had any experience with scissorlifts, but our mentors must have a really good reason for not wanting to ever have one.

[IndySam]

The Digital Goats have two rules.

#1 No casters.
#2 No scissor lifts.

[orangemoore]

I have one rule that applies to FTC more than FRC and it is as follows:

Unless you have to raise an object more than 20ft in the air. A scissor lift is not the answer.

(Bascially unless we play a game like 2011 (bowled over) again you shouldn't need to use a scissor lift.)

[cadandcookies]

Originally Posted by orangemoore

I have one rule that applies to FTC more than FRC and it is as follows:

Unless you have to raise an object more than 20ft in the air. A scissor lift is not the answer.

(Bascially unless we play a game like 2010 (bowled over) again you shouldn't need to use a scissor lift.)

Bowled Over was 2011-12. I'll agree that it was probably the only time I've ever seen a scissor lift that was actually effective. Seeing teams shoot those crate 20-30 feet up with elastic powered scissor lifts was both really cool and really scary.

If you want to be successful this year at competitions, a scissor lift is almost certainly not the way to go. Build a nice elevator or something. You only actually need one stage this year.

[asid61]

Out of curiostity, what's if it's single stage? I.E. Two bars that cross with a joint in the middle.
Assume that it's milled accurately and not made on a drill press.

[Laaba 80]

We used a scissor lift in 2013 to score the colored discs while our robot was on the pyramid. We needed a compact mechanism to lift a few frisbees a few feet, and I thought it worked great for us.

Obviously this is very different than lifting totes;however, I think they can work well in specific applications, and to automatically rule them out is a mistake.

[yara92]

Originally Posted by IndySam

The Digital Goats have two rules.

#1 No casters.
#2 No scissor lifts.

I understand why casters and agree.
but whyscisser lifts

[waialua359]

Nothing wrong with scissor lifts!

[asid61]

Originally Posted by waialua359

Nothing wrong with scissor lifts!

Why and how? This seems to be a very contradictory veiwpoint here, and I'd like to hear your thoughts. What is your experience?

[waialua359]

Originally Posted by asid61

Why and how? This seems to be a very contradictory veiwpoint here, and I'd like to hear your thoughts. What is your experience?

We built one in 2003 stack attack and it stacked bins very nicely. The scissors lift only had to go 2 bins high max.

[Al Skierkiewicz]

We built one in our rookie year (1996), we never even thought to replicate that experience since. I use a scissor type man lift here at work on a regular basis. In order for it to work well, a rigid precision frame and bearings in the joints are essential. The problem with most is the non-precision with which they are built. This leads to instability while moving and therefore intermittent loads that exceed the ability of the drive to overcome.
We have a do not use list too...
No casters/shopping cart wheels for obvious reasons.
No omni wheels on ramps.
Anything else that does not fit the game.

[sviridovt]

Let me just repeat every one here: NO SCISSOR LIFTS unless you want to know what hell feels like. The only time one should even consider a scissor lift is when you have to lift for small distances, with only one layer. Anything more will be waaaaay unstable.

[waialua359]

Originally Posted by sviridovt

Let me just repeat every one here: NO SCISSOR LIFTS unless you want to know what hell feels like. The only time one should even consider a scissor lift is when you have to lift for small distances, with only one layer. Anything more will be waaaaay unstable.

While our team probably won't be making one, I'd bet that it's still possible to create an effective one for specific purposes.
How ironic that the best VEX robots this year all use scissor lifts, where the game requires precision and going really high.

[InFlight]

A scissor lift to raise totes is probably an overly complex and likely too slow in operation compared to the alternatives.

Ideally you should want to raise the totes in an about a second or two at most.

[IronicDeadBird]

I remember doing a scissor lift and once you get all the kinks worked out its fine, but the amount of moving parts makes it more likely that things will go wrong the taller you get with it. There is a niche that scissor lifts fill and if this niche needs to be filled go for it.