Pulley help?

[MylesMyles]

We are a team that has NEVER had and success with the pulleys on our lift designs. Does anybody have any recommendations for pulleys to use on a continuous lift system?

[Stephen of REX]

Replace them with 25 chain and sprockets? I would use chain and sprockets over wire rope and pulleys any day.

[Ed Sparks]

We are a team that has NEVER had and success with the pulleys on our lift designs. Does anybody have any recommendations for pulleys to use on a continuous lift system?

We've used synchronous pulleys and belts with success. What exactly were your issues?

[bearbot]

what easier for a third year team articualter arm forklift or pulley

[MylesMyles]

I'm not sure of the brand, but they were just simple little plastic pulleys about 1.75'' in diameter. We had the cables jump out of the pulleys a lot, although this may be because our lift did not have a retraction system (unless you count gravity...).

Do synchronous pulleys use belts?

Thanks for the responses.

[Leav]

Do synchronous pulleys use belts?

I would say yes. (http://www.google.co.il/images?q=synchronous%20pulleys&oe=utf-8&rls=org.mozilla:en-US:official&client=firefox-a&um=1&ie=UTF-8&source=og&sa=N&hl=en&tab=wi&biw=1680&bih=838)

make sure to get a belt with metal cables in the backing, this will provide the necessary strength to lift a forklift without snapping.

[JosephBurns35]

i to am planning on using a winch design on a forklift type arm how would you attach a chain. and still be able to role it up. if it matters i was planning on using a FP motor with a custom drum prob out of PVC seeing as how the arm isn't going to way much. if there is a better way please help.

[MylesMyles]

Is it a bad idea to use cable for the lift? My team would like to use a cable because it is simple, but will there be quite a big tradeoff in reliability of the lift by doing this?

I'm simply wondering because it seems that most of the people responding who have experience with this have used chains and/or belts.

[JosephBurns35]

i am also wondering the same thing i used cable for my arm last year and it was a pain if anyone has any other ideas i'm open for them thanks.

[DonRotolo]

We used cable in 2007 and it was reliable and strong. Yes, it went 'haywire' once or twice, but easily corrected. In 2006 we used belting and that worked fine too. Cable (wire rope) can be 100% reliable if designed properly, and design is no more difficult than with chain or belts.

To the original poster: You need to tell us what went wrong with pulleys in the past. In general, pulleys and wire rope are good, but if you encounter a problem, you need to solve it. Once all problems are solved,. it works wthout problems.

[Trent B]

Another consideration could be cord used for climbing or something like 550 paracord. The 550 variety may be overkill, but it is more flexible than cable so it will "behave" better. By comparison a cable may be more inclined to stay bent/coiled/twisted/etc.

[Justin Stiltner]

There is a white paper in the white paper section on arms and lifts. In it you will find several ways to use cabling to achieve the results you want.

General guidelines are:

Power the lift up AND down, and make sure your cables cannot go slack.

If the cable must go slack, use guides to make sure the cable cannot come off the pulley.