Quote:
Originally Posted by ttldomination
How was the durability of the pads on this? Did you notice that the tower was swaying when all the way up high?
When we made our lift with 8020, it was fast and came together nicely. However, it was heavy. One issue that was critical was that when the tower was at its maximum height, the tower would sway. We found that this was because of the play that would develop in the plastic slides (in all fairness, those slides are meant for compression loads). In short, would not do again.
One solution that I found nice was use the iGus products. If I had to do it again, I'd have to track down exactly the types to use, but IIRC, 1771 simply used some super-light c-channel lined with the iGus products. Worked like a charm.
- Sunny G.
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We did an 80-20 lift in 2008, and in many regards, it was our best robot in recent memory. (We almost made it to division finals, I believe.)
The first stage was 2x1 80-20 with the standard nylon slides. It was slightly lightened (the back half of the 80-20 was replaced with welded on c-channel), but very similar to a system you could put together in an afternoon from regular 80-20. The second stage used v-shaped rollers that fitted into the grooves in the back of the 80-20.
While that system was fairly simple to design and execute, I wouldn't go with it again. First, it was very heavy, even with the lightening on the first stage. Second, it was poorly counter weighted. And third, the nylon sliders introduced a lot of friction into the system. You really have to pull on it to get it to lift up, and it took two CIMs to raise. I never noticed any sway, but then again, we haven't competed with it in a while.
For the OP: 80-20 is a good solution if you don't want to do bearings riding on the outside of 2x1 tubing (like 254 did in 2007 and 2011). However, don't count yourself out of that design too soon. Almost any design can be modified to fit your machining abilities, so take a look at 973's CAD to see how much machining is really required.