My team just encountered a whole 'nother ballpark of issues with our telescoping lift. The lift has been so problematic, we may just scrap the idea entirely…
We tried having two separate rows of chain. On each shaft, there were two sprockets controlling a chain. The lift only has 2 segments.
The lift is still leaning slightly, and I have no idea what to do. But our real problem- when we turned on the lift, it went up a little and then collapsed. We spent so much time lining thing up, tightening things, and so forth that I have no idea what the problem is. HELP PLEASE!
Personally, I have no experience with telescoping lifts. But I’m sure if you can post some photos, that will help others on the forum understand what you’re doing. Also, try to provide more details about the machine’s behavior. For example, what exactly do you mean by “collapse”? Did the motors shut down and the entire thing sink down? Or did you have some sort of structural failure? a chain break? or what?
Sorry, I don’t have photos available. But I can tell you the chain did not break, and the motors did not shut down. It’s like the gears violently twisted out of alignment and fell.
Apologies for my lack of accurate vex vocabulary, sort of a newbie.
It’s still a little bit confusing trying to understand the problem. Will it be possible for you to get photos? Also could you describe the problem a little more?
From what I see all I can think of at the moment is a few things:
Try moving it up and down when the chain is not connected–is anything preventing the lift from going up?
Are any of the shafts bending?
Is your chain tight enough?
Otherwise I can’t really offer any other advice except to check every part of the lift (the slides, c-channels, sprockets, chain, etc.) and make sure they are working fine individually.
Are you speaking about gears or sprockets? The sprockets fit with the chain.
Did you attach your chain to the front most stage of the lift? If so, how many motors are you using? It may be that you do not have enough motor power to operate the lift, especially if it is a cascading design. The lean however is inevitable. There will always be some give in the linear slides, causing it to lean. A few good ways to counter this are either mounting a counter weight on the Scoring mechanism, mounting the entire lift back at a slight angle, or attaching a force of tension from the top of the lift to the back of the chassis. I know painfully well that linear lifts can be a lot of work, Hope that helps!
Are you using sprockets on all your entire stack? We found that the nylon spacers are a good solution to take care of the movement elevator lifts experience during the rising and lowering process. Even with no weight on the end our lift rises fine. The only place we have gears on is in the area wear the motors actuate movement. But we haven’t solved the lean problem - yet.
We really need to see some pictures.
Perhaps also a video of what is happening, as I don’t think I’m the only one who doesn’t fully understand how the gears violently twisted and fell.
You’re definitely not the only one! It would take a ridiculous amount of force to have destroyed the sprockets in the way that I’m envisioning from her description! :eek:
Ah the noble multistage lift. We had two teams working on them and in the end, have scrapped the idea and went towards the scissor lift.
Not to say that scissor lift is necessarily easier, as it comes with its own challenges, but we have found that the steel as part of each stage of the lift just adds so much mass that it becomes difficult to overcome. Yes, rubber bands can counter this, and yes, even a counter-weight can as well, but it adds a lot of complexity.
For those groups who are capable of getting the multistage working, kudos to you. For us it was a matter of risk versus reward, versus time.
When you said the sprocket gears twisted out of alignment, I assume you mean the drive shaft cored out the inside of the gear. We had the same problem with our lift. Try using a shaft lock bar http://www.vexrobotics.com/275-1065.html on both sides of the gear (should be easily attached with screws through the holes on the gear). If you don’t have any of those, you can use the plastic lock bars [http://www.vexrobotics.com/276-2016.html. This fixed our problem, and we have a 5 stage lift so it will definitely hold the weight :p. Let me know if you need any help or need some pictures!
Jake](http://www.vexrobotics.com/276-2016.html. This fixed our problem, and we have a 5 stage lift so it will definitely hold the weight :p. Let me know if you need any help or need some pictures!)