Lift Mechanisms

[JesseCRN]

I was just wondered which lift mechanism was going to be the MOST popular for this years game: Gateway!

Please take some time to vote

Thanks!

[AndrewRemmers1902]

Dang I cant vote for two We have 4 bars and Elevators

[JesseCRN]

Is there a way to “edit” a poll and make it multiple choice answer?

Thanks!

[Thorondor]

By 2 bar linkage to you mean the bar with chain and sprocket?

[Telemascope]

@AndrewRemmers1902

Dang I cant vote for two We have 4 bars and Elevators

Haha.

@Bot-E Builders
I don’t know the official name of what you call a “2 bar”, but its not a 2 bar because thats not the way linkages are named. I mean really, it’s closer to a 1 bar. (Not that just because you have a bar on either side of the intake, does not make it 2 seperate rigid bodies.), but its definitely not a 1 bar because of the chain… Its just a simple bar with a pivot on either end, chained up so that the object on the end of the bar stays at the same rotation relative to the ground/chassis. I don’t know if there is an official name for this, but if there is I would love to know it.

[unclejoe]

Personally, I like linear slides for a variety of reasons, that have been proven in previous years.

However, I think the favorite design will be the 6-bar or 7-bar or extended 4-bar, or whatever you want to call it, but I think that lift system, with a diagonal tank-tread will most likely be the preferred/favorable design for most teams…

[bobsalive]

@unclejoe

However, I think the favorite design will be the 6-bar or 7-bar or extended 4-bar, or whatever you want to call it, but I think that lift system, with a diagonal tank-tread will most likely be the preferred/favorable design for most teams…

We eventually settled on 6-bar after a very helpful post identified it as a “Watt’s Six Bar Linkage” so we’d been calling it the right thing the whole time anyway.
https://vexforum.com/showpost.php?p=220219&postcount=10

My personal opinion is that the six-bar does not work particularly well with a tank tread intake, as evidenced by the fact that most NZ teams using six-bars have opted for top or side suckers instead. Those sorts of roller intakes seem to work better.

[JesseCRN]

@Telemascope

Haha.

@Bot-E Builders
I don’t know the official name of what you call a “2 bar”, but its not a 2 bar because thats not the way linkages are named. I mean really, it’s closer to a 1 bar. (Not that just because you have a bar on either side of the intake, does not make it 2 seperate rigid bodies.), but its definitely not a 1 bar because of the chain… Its just a simple bar with a pivot on either end, chained up so that the object on the end of the bar stays at the same rotation relative to the ground/chassis. I don’t know if there is an official name for this, but if there is I would love to know it.

I see.

Sorry about the name, and me not naming it right.

I personaly like the 6-Bar Linkage. It will be the favorite this year.

[JesseCRN]

So, what I called a 2-Bar, is not really a 2-Bar because there is only 1 bar on each side lifting say, a collection mechanism.

So would it be called a 1 bar?

[Thorondor]

@Bot-E Builders

So, what I called a 2-Bar, is not really a 2-Bar because there is only 1 bar on each side lifting say, a collection mechanism.

So would it be called a 1 bar?

its not a 1 bar either. It is basically like an arm that has chain and sprocket to keep the orientation the same.

[EDWARDZAHHH]

What I find interesting about the sprocket chained arm is that it creates a parallelogram structure and is functionally a 4 bar linkage.

I’ve definitely seen sprocket chained arms in round up and maybe clean sweep too, functioning just like a 4 bar type arm would. Never really paid much attention them other than “I see wat u did thar.” But props to 720p for making it “super effective!”

With most of the tension on the length of chain under the sprockets, have you [teams w/ sprocket chained arms] had any problems with chain snapping due to the lever effect from the ratio of sprocket radius and radius to center of mass of feed chute?

[BJC]

@Bot-E Builders

So, what I called a 2-Bar, is not really a 2-Bar because there is only 1 bar on each side lifting say, a collection mechanism.

So would it be called a 1 bar?

In FRC it is generally called a “virtual fourbar” because it functions similarly but without the extra bars. By changing the sprocket ratios you can even make an “asymmetrical virtual fourbar” which would be similar to offseting or changing the length of the bars in a normal linkage.

Pretty cool stuff, Bryan

[Telemascope]

@EDWARDZAHHH

What I find interesting about the sprocket chained arm is that it creates a parallelogram structure and is functionally a 4 bar linkage.

I’ve definitely seen sprocket chained arms in round up and maybe clean sweep too, functioning just like a 4 bar type arm would. Never really paid much attention them other than “I see wat u did thar.” But props to 720p for making it “super effective!”

With most of the tension on the length of chain under the sprockets, have you [teams w/ sprocket chained arms] had any problems with chain snapping due to the lever effect from the ratio of sprocket radius and radius to center of mass of feed chute?

I didn’t use this mechanism myself, but I did see some people’s chains snap early in the season, but if only one chain snaps, the other chain still supports the intake anyway (but not very well). Most teams have found ways to stop the chains snapping now, but they can tell you how if they want, I don’t want to give away their ideas.

Also, I have an idea for a nickname for this lift. While it isn’t an official or technical name, I think the name “Chain Bar” suits it well =).

I also want to see someone pull off this lift but instead of using chain, using gears all the way along the arm. That would look awesome, but be entirely impractical and inefficient.

[JesseCRN]

Thanks for all the clarification!

I like the name Chain Bar.

If you voted on the “Other” choice.

Would you mind telling us what lift you are using?
If you want.

I would personaly like to know what other lifts are out there.

Thanks!

[Twisted_Engineering]

My team is using a double jointed arm, where each of the two sections has a linear slide, and extends to about double its length. It is actually really stable, But it is made all steel parts, no aluminum. it weighs a lot, and I am quite surprised that we have yet to twist the main axle that supports all the load. It has a lot of bounce, so we are somewhat worried…

[AlexZ]

I voted as elevator lift but I would like to specify that we are using a shuttle on a 40" track.