In the actual lift we made the chain wasn’t quite so close together and the idlers were mounted so there was more slack. I must confess, I put them in those particular holes without really thinking
Usually the slack causes the chain to skip around and the intake to end up at funny angles (sometimes still usable in competition though) but can potentially be a problem. Snapping of the chain hasn’t been as common (as far as I’m aware) but one example that I have personally seen was when the robot’s arm crashed down on the isolation 20" goals with the chain hitting the goal’s uprights.
I agree. In fact, the robot the CAD was semi based off uses a chain lift. That term was meant to be temporary and as with most temporary things (in AURA), seemed to stick.
You can move the idlers but they seem to decrease the slipping of the chain quite dramatically in my experience, of course you could position them differently to reduce friction, or remove them entirely.
I disagree. A “lift” to me means whatever mechanism allows the intake to move relative to the rest of the robot, not neccessarily including whatever powers that mechanism. That usage had to come from somewhere, so I believe that’s probably what most people doing Vex in New Zealand mean and understand by it.
And a linkage is a set of rigid links connected by pins or sliders.
Technically it is, since each chain link is rigid and connected by pins…
I’m in favour of “chain linkage” because the purpose of the chain is to link two things, not the lifting itself. But I don’t think it matters too much.
Fastening the chain to each sprocket at some point where they never separate would fix the slipping problem even more dramatically.
Put the arm at the lowest point, mark each link that is touching a sprocket tooth.
Put the arm at the highest point, any marked link that is still touching the sprocket can be bolted down to the sprocket.
That’s actually a great idea and would work, but how do you bolt a chain link to the teeth of the sprockets? You could probably still cable tie the chain down, through the holes of the sprocket.
Perhaps try using an attachment link and a scrap piece of metal (maybe a 1 by) as a 90 degree bracket on each side to the sprocket. Not a pretty solution, but it would “bolt” the chain link to the sprocket.
The problem is “chain lift” implies many things, such as a vertical lift powered by chain. Note that unlike an arm, a vertical lift doesn’t have a better name for it than “lift”.
A “chain lift” as you call it is a linkage. That’s just what it is.
