About our robot's hanging potential...

Hello vex forum. Thanks for all the help everybody gave me. We did well on our last tournament and we are going to georgia state. In the four weeks before the competition we really want to be able to high hang with a large ball. Let me post the basic information about our bot:
Base: four motor tank drive 1:1
Lift: four 393 geared 1:5 , six bar lift with rubber bands to prevent falling down
I have heard people saying that high hanging can be achieved with a gear ratio of 1:5. I haven’t tried it yet, but the problem is the lift has absoutely no trouble lifting itself up, but has trouble staying at any height. It always falls back down when the motors are not powered. To solve this issue, plenty of elastics are added to cancel out the gravity, which also eliminates the potential of high hanging.
In the tournament we found out that even we overdrive the lift a little bit, meaning keep activating the motors at the lift’s maximum position, the lift will not crack anything. It will just stay there and is pretty safe. This being true, we can actually take off all the bands and keep holding the buttons when we are stashing. That will give us more hope of high hanging, but also brings the motor overheating issue. Also if we play like this, it will be harder for our driver to lock or unlock buckies. What do you do, teams with hanging feature?

Most teams that hang have a 1:7 on their lift and have a lock. Your lift would be slightly slower, but you could get 20 points from a hang. The only team that I have seen that hangs with 1:5 and 4 motors had pneumatic assist.

I have indeed seen some teams that use both bands and double acting pistons to help high hanging. I honestly don’t wanna try that because I wanna keep everything simple. But if that is necessary to achieve a good fast high hang, I will try it.

And yes, I have already put the chain outside the lift tower and ready to place a pneumatic piston to make a lock.

We hang with a 4 motor 6 bar lift. We use a hold button that keeps the motors set to 10 to prevent the lift from dropping so we don’t need rubber bands to hold the lift up. So there are basically 3 buttons for our lift, up, down, and hold. I hope this helps.

Thank you for your help. But I am still a little bit confused. How do you keep your lift at a position using programming? Do you use pneumatic lock or anything else?

Oh nevermind I now understands. So you guys keep your lift up by programming the motorsnto go slowly up to keep the torq right? Thanks so much man that is so enlightening.

While not as fast as the hanging devices with the higher gear ratios, our teams find that using a winch is a very effective hanging method. This way, you could free up some motors on the arms.

To keep from having to use a “hold” button, you can have your robot “remember” whether an up button or a down button was pressed last.

Feel free to ask if you have questions.

bool lastLiftBtnPressed = false; //this has to be global or...
void liftControl()		//...static inside the function
	{
	int tempLift;
	if (vexRT[Btn5U]) //Up - 1
		{
		tempLift = 127;
		lastLiftBtnPressed = true;
		}
	else if (vexRT[Btn5D]) //Down - 1
		{
		tempLift = -127;
		lastLiftBtnPressed = false;
		}
	else if (vexRT[Btn5UxMtr2]) //Up - 2
		{
		tempLift = 127;
		lastLiftBtnPressed = true;
		}
	else if (vexRT[Btn5DxMtr2]) //Down - 2
		{
		tempLift = -127;
		lastLiftBtnPressed = false;
		}
	else //Neither
		{
		//FROM HERE...
		if (lastLiftBtnPressed)
			{
			tempLift = 10;
			}
		else
			{
			tempLift = 10;
			}
		//...TO HERE can be replaced with...
		//tempLift = (lastLiftBtnPressed) ? 10 : 0;
		//...the previous line. Only use it if you understand ternary.
		}
	
	Motor[LIFT_LEFT_1] =  tempLift; //Set your motor values!
	Motor[LIFT_RIGHT_1] = tempLift;
	Motor[LIFT_LEFT_2] =  tempLift;
	Motor[LIFT_RIGHT_2] = tempLift;
	}

This code is not tested.

EDIT:
Some people use bungee/rubber bands pulling the lift down so it assists while hanging.
You might want to see this post, maybe the entire thread… https://vexforum.com/showpost.php?p=340812&postcount=18

A pneumatic lock won’t require much force or air, so you could probably use it whenever you want to keep the lift at constant height (including when you hang) instead of rubber bands.

Thank you for your suggestion, but we still wanna try the simpler way to keep the lift high. We wanna try to send a signal to the motors when the buttons are not pressed to let the lifts go upwards slowly. No visible movement should be seen if we put in the right motor speed, like 10 perhaps, and the torque is being supplied.
The main thing is, our team is in an academy that teaches robotics. For the lessons, metal pieces are good so we did not bother to buy aluminums. But we did not realize how annoying this issue of weight is until we wanna hang. Now we have one 125 c channel, four 52 c channels and two linear slides made of non-aluminum alloy on our base, also all the heavy lift bars. So the last thing we wanna do is putting on two heavy pneumatic tanks for some exlerimental results.