Madeline here. It looks like the current meta for robots this season has been a dr4b lift with either a 4bar or a 6bar at the top. I was wondering why teams aren’t using a dr6b for the lift as I think that the added height may be a bonus without having to use such a long piece of metal at the bottom of the lift. Any ideas?
A dr6b does give you more height but at the cost of valuable weight and space. Also the added height would come at a much higher instability needing much more bracing which is even more weight. Also the cone difference would be by at the most 3-5 which to me is personally why I like a dr4b. I will note that using a 6 bar on top makes it a lot easier to mount my chain bar manipulator at the front which is why I do that.
They lean backwards a ton, especially with a large amount of rubber bands. I had one but ended up getting rid of it. They are also, as others have mentioned, extremely heavy and are hard to run, especially with two motor lifts. Not only that, they require a lot more torque and have a lot more friction due to having many more rotational joints than a dr4b.
Maintaining stability in a dr6b is a really just a product of good build quality. If you have good build quality, you should have no issues with stabilizing a dr6b. Really the only point that I can’t argue with is the added friction because there are more joints, but I can vouch that it does not really affect it.
As for weight, there is a huge craze about building the lightest robot possible, which isn’t bad, but it isn’t necessary. The added weight of a dr6b is negligible.
From experience - a dr6b takes more unecessary work, and in this season, building a good dr4b is plenty tall enough where the stabilization and fine-tuning of all the screws of the dr6b aren’t really necessary. A dr6b does look a lot cooler tho (especially when compacted). Weight can be countered using banding, but inertia…
We could do HS 1:3 on a dr4b, but with a dr6b the momentum/inertia (I forget physics man that was wayy back in october) we could only do 1:5.