calculation clamp socket box

[Lorenzo_]

Good morning
Sorry about the banality of my question, but I have no experience about it.
I would need formulas for calculating the grip force to lift a box.
I have on a robot wrist a pneumatic cylinder with rack moving 2 palettes in a self-centered way to take a heavy box 20kg and lift it.
I have no clear what is the formula for calculating the force necessary on the palette to lift and move the box.

excuse my ignorance again

Thank you.

 

[wert]

If I have well understood, the two pliers will sit on the box, without any subsquadro, then what allows you to lift the box is the only friction between box and pliers. you must trace the friction coefficient between the material of the box and the material of the pliers.

 

[Lorenzo_]

Yes.
the box is a common cardboard, for the shovel I have stickers made specifically to increase friction, but removed this point, I should understand how much force the cylinder has to do.

 

[Vittorio]

Hi.
data is not enough.
post a picture of the box to be lifted and a photo of the robot with its clamp.
if you add the air cylinder tone.. even better

 

[Lorenzo_]

Hi.
data is not enough.
post a picture of the box to be lifted and a photo of the robot with its clamp.
if you add the air cylinder tone.. even better

Hello vittorio
no I do not have the cylinder's edge, I would like to know how to find the necessary force of thrust and then I choose the cylinder to use. this is not a commercial caliper, but it must be custom for encumbrance issues.
the idea is to use a cylinder with a rack mechanism to make self-centering closing. or 2 cylinders, which each one commands a closing blade. I don't have much at the moment as a drawing

 

[Vittorio]

the shape of the box is important.
useless to write rivers of words and make boring and incomprehensible discussion.
if you have pictures or sketches made by your idea.. postal.
after which you can make targeted considerations.

 

[wert]

Yes.
the box is a common cardboard, for the shovel I have stickers made specifically to increase friction, but removed this point, I should understand how much force the cylinder has to do.

So it's just the friction that will allow you to lift the box, okay. I imagine you will know that the friction coefficient at the most can be 1 and that only in that case you will just tighten the box with a force of 20 kg to raise it (in theory, then you have to evaluate dynamically). as you will hardly find two materials that come to have a coefficient close to 1, your strength will increase to the drop of the coefficient. therefore consider even if your box can be crushed with the force you will go to find without being damaged; You may be forced to use a different principle that excludes friction as force (such as vacuum, to make an example).

 

[Lorenzo_]

Thank you.
I had opted at the beginning for suction cups, but I have to discard them for the conformation of the box.
thank you very much for the clarifications, I am very helpful

 

[Dum]

of friction alone, being a cardboard box, risks complicating your life.
add 2 suction cups that work well on the cardboard (to make you an idea you can go on the piab finger, there is for every application taste), limit the race of the griffe so that I snap the suction cups and not beyond and the box does not destroy it.
I would start with this principle, but without other data it is difficult to give you a more targeted advice.
If it is well closed, you could even avoid the gutters and act directly from above, always with suction cups.
or itchings make a mix, both with a couple of suction cups on the upper and 2 side level. .

I mean, there's a lot of roads. .

 

[Dum]

Thank you.
I had opted at the beginning for suction cups, but I have to discard them for the conformation of the box.
thank you very much for the clarifications, I am very helpful

Sorry, posted before your surgery.
Is there any way to see at least a drawing made on cheese paper of these boxes?

 

[wert]

If your box has to be laid somewhere where there are no constraints (such as the walls of a box), you could make the "l" palettes. It would suffice a length of a few millimeters of the horizontal flap to remove the thought of friction. with a minimum grip force you would ensure lifting safely. but as I wrote, for this solution it is necessary that once the box is laid, there is the horizontal space to "seat" the box from the palette.

 

[cacciatorino]

on average, for sockets without "incastrious", that is, based only on a force of deemed (obtained by friction or depression little matter), a force that is 10 times the weight of the object is taken as a base parameter. consider that you should not only win the weight of the object, but also the inertias due to the accelerations of the robot.

 

[meccanicamg]

we see to sum up and give some extra info.

As they have already told you, you try to have a lifting capacity at least one extra order of magnitude than the weight, then 20kg*10=200kg admitted that the socket does not deform the box.

the knives definitely help greatly because they are fingers of the clamp that holds the load.

the system sprocket racket allows to move with a cylinder only one rack and get a self-centering system. You may also think of correcting a pneumatic torque engine known on the pinion and obtaining costs on the racks.
Other link.
Other idea.
on the forum there is a lot.

the vertical friction force that contrasts the weight is made by the closing force multiplied the friction coefficient.rubber/paper if you get to 0.5 of friction coefficient is already good thing. you can determine experimentally with a sloped plane and with the tangent of the corner you have the coefficient of friction first detachment.

here under a scheme of lazy racks of a rotating cylinder to be used for reasoning.

 

[brn]

If possible I would do l that stick under the box and a cylinder to hold it there.
20 kg are not very few if you have to tighten it to lift it comes out a discreet force (as they told you earlier) but is box not destroy it with strength? Is it a box or a rigid box?
I'd never take it for friction.
Do you have the risk of scoring or ruining it?
more than the formulas that in this case are trivial I would worry that the lifting solution is the suitable one.. .