Four-bar or Six-bar?

Which would work better for the tournament?


it depends on what you want your robot to do. if lifting higher is your goal, a 6 bar might be the right choice. if you want simplicity and don’t need to lift too high, a 4 bar could suffice.


It depends a little on your strategy. Are you planning on being primary defensive or offensive? 6 bars have a higher extension so you would be more likely to be able to get all towers and you could have a higher stack. However, a good 6 bar is harder to make than a 4 bar. Then 4 bars have a shorter extension, perfect for making initial stacks at the beginning and then playing defense the rest of the match


Unless you extend the 6 bar past 35, I don’t believe there’s a way to lift past the top tower, so 4 bar would be optimal I believe.


Maybe the four-bar would work.

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Thank you! I’ll think about it.

Double reverse four bar is what you want. A single four bar or a single six bar won’t be high enough to score the top tower. There are many other threads that can explain this for you.


@Sage, have you thought about what a six bar could do?

Not to nitpick, but I believe you are talking about the double reverse 4 bar and double reverse 6 bar right? A 4 bar is something else, and I dont know if 6 bars exist(do they?)
Anyways, just a simple reminder.

But i think a dr4b would be better, simply because a dr6b is so extra

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6 bars do exist. they are similar to 4 bars in application and movement, but reach a little taller.


A 6-Bar can reach the top tower if built and spaced correctly, but DR4Bs have linear motion, and that is a huge advantage.


What a mechanical engineer would call a 6-bar linkage and what the VEX world calls a 6-bar are different things. The VEX world calls two parallelogram 4-bar linkages connected at a single corner and sharing a bar in common a “six bar”.

Basically, the bottom bar of a 4-bar is split in half, then the distal half is moved up so it’s now on top. An additional bar is added at the split, running along the vertical translation. It lets the long bar be a little longer without affecting the robot’s overall height.


No, they can’t reach the top tower. But as we’ve seen, that’s only one of 7 towers. One tower is a pretty small sacrifice. (Basically, 6-bars can be good!)

Do you think that a DR4B, if built correctly could reach the top tower?

Yes, a correctly built DR4B can easily reach the high tower. I would before you start building anything review all of the rules around point values and consider the necessity of having a DR4B to reach the high tower.

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Thank you for the suggestion!