In the hanging lock conversation I saw some pretty interesting ideas, but I want a passive lock that can be used multiple so that I can hang in autonomous and then get down to play in the match and then be able to go back up to hang at the end of the match without using any more motors or pneumatics.
I just came up with one the other day.
I’ll make a video of it this afternoon when I get a chance.
It is hard to unlatch a passive lock without some powered element to unseat it. Passive locks tend to spring into place and are held by gravity. Keyed locks, rubber band fed bolt locks, and other passive mechanisms are the norm when you want to not have motors involved.
You could make something that unlatches as you add power like a window shade, but that may require too much power to overcome the hanging robot weight. Lets see what @SamuelC (7842D) has…
that is basically what i am thinking of. But i took apart a projector screen to see it in more detail.
Here it is, this is what I have @Team80_Giraffes 
.
I only had lego to prototype it with.
The light grey snapping block represents the robot’s drivetrain.
I’m not sure how to explain how it works so I hope that it’s self explanatory.
Honestly when I asked, I wasn’t sure that it was possible, but that’s exactly what I was looking for.
How much resistance is there when it’s releasing from the lock?
It doesn’t feel like there’s any more resistance at all.
My main concern with this design is that all of the weight of the robot is being rested on the linkage.
Are there any other mechanisms that can be used for this purpose? I can only think of the one.
So the whole robot would have to turn 90 degrees into the air for the hang? Not sure if I want to subject my robot to that kind of stress…
It doesn’t have to work like that, you can build it into a scissor lift.
I can prototype that tonight to show you (around 11:00 you time :/).
Also, I’m unclear as to what the problem you have with that is.
It would be easier to pull up that way to avoid getting caught on the wall or brackets.
It requires more torque. Assuming the CoG is in the center of the robot, 1.41x torque is needed.
I understand that, and I’m not sure the mechanism would be able to support the weight of a heavy robot, but this is a passive multi use lock, what do you expect
Also, I think that it’ll be difficult to hang a heavy robot no matter what.
I’ll still try to prototype the scissor lift version.
It seems like the kind of thing where you know how it works but don’t know exactly why it works. I’ve also found Lego to be a great prototyping medium, since you can get the same gear ratios (except for 1:7) with the same number of holes, and it helps that you can use them over and over again. Funny thing though, the Lego motors are much more powerful than vex.
Seems like the world needs MOAR TORQUE!!!
Oh, @SamuelC (7842D) where’s that video of the VEX prototype that you were talking about?
Sorry, I made a quick video and then completely forgot about it.
Give me a few minutes to find it and upload it.
I still only have lego to prototype with, but I think that this could be scaled up still.
I don’t have lego gears with hole spacing between 45˚ and 90˚ so I used the wheels with 60˚ spacing.
Just pretend that it had teeth and was powered be the smaller gear beside it.
Edit:
LOL, I uploaded the wrong video, just 5 more minutes.
Finally, here it is.
Sorry for the quality, both of my lights died and the only camera I have is built into my 11 year old computer.
Anyone else getting that super weird recommended thumbnail after the video? Lmao this has nothing to do with the conversation but it was too funny not to point out lol.
Oh yeah i love me some scissors in a toaster
On our hang, we used torque motors and insane gearings, so we don’t have to worry about making a lock, since it is extremely hard to move the torque motor.