7504B Need Elevator Lift Help!

Ok, so my team is building a elevator lift for skyrise. We have gotten the first section to work but cant get the second to lift. Some pictures and a video is included. Thanks!

http://youtu.be/1z4_vATehAI





The chain must be physically tied to the first stage in order for the continuous elevator to work. Most teams use a screw to bind the chain to the first stage.

Also, try to make the chains parallel to each other. Otherwise you either create slack when you raise the lift or the chain snaps.

From what it looks like in the video, you need to attach something to the chain (the bottom of your second stage or a third stage) so that it can move with the chain.

It may not be your problem right now, but your idler sprocket out front needs to be directly below the final stage.

On the second tier how many sprockets do you have attached to it?

I dont have the robot with me right now, Ill tell you as soon as i know

Thanks for all of the posts so far , ill try all the suggestions as soon as i can!

If it helps here is a little animation (thanks to jpearman) of an elevator lift. If the chain is going around the sprockets but doesn’t lift anything, Look at the last stage (farthest away from the motors) and make sure the chain is attached to the stage at the bottom.

After watching the video, it is clear that the chain is just running through the series of sprockets. In order for the motors to actually pull the lift all the way up, it must be attached to the front stage. That is a MUST. It actually just pure luck that the first stage went up at all, normally I would have expected the chain to just run through the series. All you need to do is attach the chain to the front most stage and all of your problems will be fixed. Attaching the chain to the front is a necessary aspect of an elevator lift, no matter how many stages you have for your lift. Trust me, I speak from experience :smiley:

The idler sprocket that is attached with just 2 standoffs really needs some more support. With any amount of tension or load on the lift those 2 standoffs will not be enough support.

Another team from my school, 4184G is building one of these lifts and it works pretty well. I am sure that they will be posting videos of it after we compete on Saturday. Good luck!

near the bottom of the page it explains elevators. Like smiles1217 sid, you have to affix the chain to something.

Otherwise you just build the first Vex chain saw! :smiley:

http://curriculum.vexrobotics.com/curriculum/lifting-mechanisms/elevators