This video is a good guide on how to make a dr4b
So I know that the general consensus for rubber banding a DR4B is that a triangle is the best shape. However, I have a few questions about some more technical aspects on the choices that teams make when rubber banding their lifts.
For one, why do most teams only rubber band the bottom part of the DR4B? I’ve been rubber banding both the top and bottom four bars and it works just fine, so is there a particular reason that the bottom is usually the only part rubber banded?
Also, why do most teams…
I’m currently building a DR4B, and I am encountering many problems. my lift keeps leaning, but it isn’t because of weight, since it sometimes leans left, and sometimes leans right. The lift is also generally unstable, and wobbly, despite multiple, tight screws into the base, and support bars wherever I could put them. Are there any particular tips for these kind of issues?
So two questions:
We only have room to crossbrace our top four bar on the DR4B and were wondering whether it would really be necessary? Our DR4B seems sturdy enough for now.
Is there a big difference when using pulleys with the rubberbands? I’ve heard it helps even the tension across each section of the rubber band triangle. Right now we are just using spacers that can roll but not wiggle around.
We are attempting to use a double reverse four bar, but it is extremely heavy and barely lifts even with 2 motors and a TON of rubber bands. The screws attaching the gears to the channels are bending (even with standoffs there) and making the bars not parallel as well. Any suggestions?
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