I’m doing an eight bar lift, but I’ve seen that without the arms raised, the lift’s lenght is over 45 and this is not allowed. Do you know how to do an eight bar lift which will raise the necessary height without surpass 45 cm in its repose position?
Do you recomend me use two motors for each arm?
I recommend two motors per arm and is the sizing limt do you go over it with your intake on it? Also is 45 cm 18 inches?
Not sure exactly what you’re looking for, but you are allowed 18 in x 18 in x 18 in. In metric units, that would be 45.72 cm x 45.72 cm x 45.72 cm, so actually just over 45 cm.
Well, my eight bar height is good, but the lenght is around 47 cm, and this is not allowed. I’m looking for an eight bar lift’s example which has the allowed measures. And thanks for your answers
Just shorten one of the “4-bars” that make up the 8-bar. You only have to be 2cm smaller, so that’s not a big problem.
You can do an 8 bar lift and fit in the size requirements. We also do 1 motor per lift side, and are able to hold up to 3 cubes and a peg.
Not to be rude but i cannot imagine a 2 motor 8 bar holding 3 cubes and being efficient , do you have any videos of it lifting up in a reasonable time. I personally have a 4 motor DR4B, and i can lift up in 1.8 seconds. So i think a reasonable time would be 3 seconds. But that is with 4 motors and a pneumatics.
I was kind of thinking the same thing. Sounds hard to believe. Would love proof of it though!
The 8 bar robot that won the skyrise vex summer games, team 359(A i think) had a 2 motor 1:7 8 bar.
You could see how it was lifting 2 cubes at good speed, so I’m not surprised.
They actually held 3 cubes with 2 motors and an 8 bar lift in a few competitions after that, but in the last competition I saw with them, they switched back to a 2 cube intake. I could see their arm dying when they held 3 to put on the skyrise at once, when they did.
I think making a compound gear ratio a bit torquier than a 1:7 would be great for doing 3 cubes.
This is true. Durability became an issue, however it did hold up pretty well for a long time during practice at school and several events. The trade off was being able to have a 6 motor drive.
After doing the China Asia Pacific, we now have more details, experience and decisions to make how we plan to improve in design, re-evaluating the trade offs, or sticking with the status quo.