Simple Mechanics Problem, Forces and arms.

[berko1]

Hello all,
1st time posting here, hope I'm in the right place.

1. I am designing a mechanical gripper arm that is supposed to grip from the inside out. I am stuck with a design calculation of the forces that i need for the actuator. The problem is that by my calculations i will need a linear force that is about 2.2 the force i am getting out (perpendicular to the force movement).

2.

The green is tacked to the body and the rest is only restricted by the design.

I called the Linear force Fm and the output force Fn. By my calculations:

Fn=Fm*tan(alpha)

3. Alpha is restricted between 15-45 degrees. And I need Fn to be 235N. The arm is one of three (equally spaced) so I need the actuator to push all three of them. By my calculations:
235*3=705
Fm=Fn/Tan(alpha)=705/Tan22=1750N
*22 is the angle which need more force.

The actuator needs to be 1750N. which seems way overkill..

Is this the correct way to calculate this? It seemed very right until i got the answer.
Thanks in advance!

 

[KataKoniK]

Hello there! Welcome to the forum. It sounds like you are working on an interesting project. I am a scientist with experience in mechanical design and I would be happy to offer some advice on your design calculation.

Firstly, it is important to make sure that your calculations are accurate and take into account all relevant factors. From your description, it seems like you have correctly calculated the output force (Fn) based on the angle (alpha) and the desired force (235N). However, I would recommend double checking your calculations and making sure you have accounted for any friction or other resistance in the gripper arm.

Secondly, it is important to consider the capabilities of your actuator. While it may seem like 1750N is overkill, it is important to make sure that your actuator is able to handle the force required for the task. It is always better to overestimate the required force rather than underestimate and potentially have a malfunction or failure.

Additionally, it may be helpful to consider alternative designs or materials that could potentially reduce the required force for the actuator. Is there a way to redesign the gripper arm to reduce the angle (alpha) or decrease the friction in the system? Exploring different options could potentially lead to a more efficient and effective design.

Overall, it seems like you are on the right track with your calculations and design considerations. I would recommend double checking your calculations, considering alternative designs, and making sure your actuator is capable of handling the required force. Good luck with your project!