HELP Elevator/Lift!!!

[Jon Stratis]

The elevator design your referring to has two moving stages... and believe it or not, you can power both stages with a single motor! We built a similar elevator in 2008, and it looks like the team is leaning that direction again.

http://www.chiefdelphi.com/media/photos/30267
http://www.chiefdelphi.com/media/photos/35975
http://www.chiefdelphi.com/media/photos/35974

In order to power it with just one motor, you need to think through how the pulley's and the cable that lifts it moves. It starts near the bottom, and runs up to a pulley on a stationary cross member (this pulley never moves). From there, it runs down to a pulley on the outer-most moving stage. If you were to just tie it off here, it would life that stage up. But, since you go around a pulley there, you can send that up to a pulley at the top of the same stage. The distance between these two pulleys is fixed, since they are part of the same stage. From there, you run it down to the inner-most moving stage, and tie it off.

When you end up powering the motor, the inner-most (smallest) stage moves first. When it gets to the top, then the middle (the outermost moving) stage moves. In the end, the whole thing extends!

Attached is a quick diagram of how the cable runs work. The blue is the cable, and the gray is each stage. White circles for the pulleys, a big black circle where the cable gets tied off.

[IFB662]

Originally Posted by eagle33199

The elevator design your referring to has two moving stages... and believe it or not, you can power both stages with a single motor! We built a similar elevator in 2008, and it looks like the team is leaning that direction again.

http://www.chiefdelphi.com/media/photos/30267
http://www.chiefdelphi.com/media/photos/35975
http://www.chiefdelphi.com/media/photos/35974

In order to power it with just one motor, you need to think through how the pulley's and the cable that lifts it moves. It starts near the bottom, and runs up to a pulley on a stationary cross member (this pulley never moves). From there, it runs down to a pulley on the outer-most moving stage. If you were to just tie it off here, it would life that stage up. But, since you go around a pulley there, you can send that up to a pulley at the top of the same stage. The distance between these two pulleys is fixed, since they are part of the same stage. From there, you run it down to the inner-most moving stage, and tie it off.

When you end up powering the motor, the inner-most (smallest) stage moves first. When it gets to the top, then the middle (the outermost moving) stage moves. In the end, the whole thing extends!

Attached is a quick diagram of how the cable runs work. The blue is the cable, and the gray is each stage. White circles for the pulleys, a big black circle where the cable gets tied off.

This is very interesting my team has always used pneumatics for our elevators but are considering something with pulleys for this year.

[TD78]

Originally Posted by eagle33199

The elevator design your referring to has two moving stages... and believe it or not, you can power both stages with a single motor! We built a similar elevator in 2008, and it looks like the team is leaning that direction again.

http://www.chiefdelphi.com/media/photos/30267
http://www.chiefdelphi.com/media/photos/35975
http://www.chiefdelphi.com/media/photos/35974

In order to power it with just one motor, you need to think through how the pulley's and the cable that lifts it moves. It starts near the bottom, and runs up to a pulley on a stationary cross member (this pulley never moves). From there, it runs down to a pulley on the outer-most moving stage. If you were to just tie it off here, it would life that stage up. But, since you go around a pulley there, you can send that up to a pulley at the top of the same stage. The distance between these two pulleys is fixed, since they are part of the same stage. From there, you run it down to the inner-most moving stage, and tie it off.

When you end up powering the motor, the inner-most (smallest) stage moves first. When it gets to the top, then the middle (the outermost moving) stage moves. In the end, the whole thing extends!

Attached is a quick diagram of how the cable runs work. The blue is the cable, and the gray is each stage. White circles for the pulleys, a big black circle where the cable gets tied off.

what did you use for bearings for the inner most stage riding on the outer stage?

[Jon Stratis]

I'm not sure what the exact product was, but we used the same items for each stage. We built small brackets that could hold the rollers/bearings outside the adjacent stage, holding the whole thing together. You can see them about 2/3 of the way up the picture here:
http://www.chiefdelphi.com/media/photos/35975

The rollers are white, and duplicated front and back. The innermost stage has the rollers attached to itself on both top and bottom to hold it inside the middle stage, while the middle stage only has rollers attached to the bottom (extending out to wrap around the outer, stationary stage), while the outer stage has rollers at the top to wrap around the middle stage. This way, the inner stage remains completely within the middle stage at all times, while the wheels at the bottom of the middle stage approach the wheels from the top of the outer stage, holding it in place as the stage raises above the outer stage.

[Dad1279]

Lots of pics here, nicely organized: http://www.firstroboticscanada.org/site/node/96