Force calculation - Gripper (Torsion Spring)

AI Thread Summary
The discussion focuses on calculating the force required to operate a gripper using a torsion spring for holding a circular tube made of SS316. The gripper, constructed from Aluminium 6061, functions similarly to a clip and requires manual force to open. Key points include the importance of preload in determining spring force, with insufficient information provided about the unloaded geometry of the spring to make accurate calculations. The design of the torsion spring significantly influences the force exerted, as variations in spring construction can lead to different contact forces when the gripper is closed or when a tube is inserted. Overall, the calculation of the spring load is contingent upon the specific design and characteristics of the spring used.
psugumaran
Messages
3
Reaction score
0
Hi,

Currently I am working on a project to find out the force required to open/close the gripper for holding a circular tube. I have used torsion spring between the two gripper and it will work like a clip. The circular tube is SS316 and the gripper is made out of Aluminium 6061.

Stainless tube 316 OD = 30mm and ID=20mm (Attached figure for reference) length of the tube = 100mm

Please help me how to calculate the force on torsional spring. Thanks in advance
 

Attachments

  • Torsion spring_Calculation.JPG
    Torsion spring_Calculation.JPG
    34.3 KB · Views: 947
Last edited:
Engineering news on Phys.org
If I correctly understand your figure, the force on the spring depends on the way you preload the spring which is a function of the unloaded versus loaded spring geometry. Your figure shows the loaded geometry, but not the unloaded geometry, so there is not enough information to evaluate the spring force.
 
Thanks for your reply. You are right, spring is preloaded when the gripper is in closed position. The gripper has to be opened by manual pressing (finger) force then the circular tube is pressed into the gripper to hold it in position (Attached Figure for reference)
I thought of using double torsion spring in the gripper, It will work like opening and closing of hair clip. Hope this will give you a clear idea.
 

Attachments

  • Gripper opening_Torsion.JPG
    Gripper opening_Torsion.JPG
    44 KB · Views: 961
There is still not enough information to calculate the spring load.

It all depends on how the spring is made.

For example, the spring could be made such that, with the gripper closed, there is no force in the spring and consequently no contact force between the gripper and the tube (even though the gripper is "closed.")

For a second example, with a spring made differently, with nothing in the gripper (no tube), the ends of the gripper could be pressed together with some very high force, and when the tube is inserted, an even higher contact force will develop.

It all depends upon how the spring is made (as I think I said previously).
 
How did you find PF?: Via Google search Hi, I have a vessel I 3D printed to investigate single bubble rise. The vessel has a 4 mm gap separated by acrylic panels. This is essentially my viewing chamber where I can record the bubble motion. The vessel is open to atmosphere. The bubble generation mechanism is composed of a syringe pump and glass capillary tube (Internal Diameter of 0.45 mm). I connect a 1/4” air line hose from the syringe to the capillary The bubble is formed at the tip...
Thread 'Physics of Stretch: What pressure does a band apply on a cylinder?'
Scenario 1 (figure 1) A continuous loop of elastic material is stretched around two metal bars. The top bar is attached to a load cell that reads force. The lower bar can be moved downwards to stretch the elastic material. The lower bar is moved downwards until the two bars are 1190mm apart, stretching the elastic material. The bars are 5mm thick, so the total internal loop length is 1200mm (1190mm + 5mm + 5mm). At this level of stretch, the load cell reads 45N tensile force. Key numbers...
I'd like to create a thread with links to 3-D Printer resources, including printers and software package suggestions. My motivations are selfish, as I have a 3-D printed project that I'm working on, and I'd like to buy a simple printer and use low cost software to make the first prototype. There are some previous threads about 3-D printing like this: https://www.physicsforums.com/threads/are-3d-printers-easy-to-use-yet.917489/ but none that address the overall topic (unless I've missed...
Back
Top