Forklift Dilemma

[NorviewsVeteran]

We decided to try a forklift style mechanism this year, the polar opposite from our 2007 robot. After some deliberation and a lot of searching and looking at photos on here on CD, we're using 8020 for the sliding pieces and their linear bearings along with it. We have built it to the stage where you pull on the cord and it goes up (and barely bumps the ceiling in the shop at 9' 3") and it comes down needing only a little assistance. The next step is to motorize it, but we can't decide what medium to use: chain, rope/wire, or belts. As a side note, we've already determined to have it as a closed loop so it can be powered down.

Here's what we know about each medium:

With chain, it wouldn't need a drum to collect excess, it would just go past the driven sprocket and be on the other side, never slip (when properly tensioned), but it's heavy.

Rope/wire is lighter but the excess would need a drum to collect it, and if it's a closed loop it may slip.

We hardly have any experience with belts, and aren't sure how much it would stretch over an approximately 20' length.

If anybody has more knowledge or experience on the subject, please let us know what we got wrong.

Thanks!