Quote:
Originally Posted by M4 Sherman
Whatever you do, dont use draw sliders! My team did that last year, and it worked terrible.
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Assuming you mean drawer slides, I couldn't disagree more. Last year, my team used heavy-duty ball bearing drawer slides that we got at a local hardware store (you can get similar off of McMaster-Carr; but Home Depot, Lowes, etc. don't carry them) and it worked beautifully. The friction was very low and we never had any binding problems. 217 and 229 used server rack slides in 2005, and that also worked very well (where we got the idea, actually). I think 111 may have used something similar in 2005 as well (their linear bearings look very similar anyway, just much larger). I imagine that if you used bad drawer slides (like those from Home Depot) that they might not work well; however, with some decent slides they work great! If I was building a elevator this year, I would either make it like the how Poofs/RAWC did last year, or with drawer slides. Those 80/20 sliders, while quite usable, IMHO, just don't compare to the smoothness and low-friction of running on ball bearings.
BTW, I would be careful about using pneumatics for big actuations... it may look like there is a lot of air stored on the robot, but a 24" stroke cylinder can blow through it pretty quick. Imagine this: you're in match three of the finals on Einstein, you're trying to stick the ball on the overpass to seal a win and your air runs out
. Constantly running the compressor will heavily eat into your battery life, too. Don't get me wrong, I love pneumatics for short, fast actuations (like a gripper or shifter) or even one-time/very infrequent large actuations (like ramps last year or unfolding a mechanism), but I just wouldn't use them when I need a big-bore, long cylinder to do a job that needs to be done many times.