connection with 5 DOF

[misiek_wro]

Hi all.

what kind of connection I should use, to create in mechanism this connection? I need 5 degrees of freedom (3 rotations, 2 translations)



View attachment 3744
View attachment 3745


Edited by: misiek_wro

 

[Israr]

Gerneral connection with constraint of point on plane.


Israr
Edited by: Israr

 

[Kaz Z06]

Unfortunately, Israr's original suggestion of using a "bearing" joint will not work. If I interpret your image correctly, it appears the ball is allowed to move freely anywhere on the flat surface (2 degrees of translational freedom), but can rotate in any direction (3 degrees of rotational freedom). A bearing joint constrains the body in 2 translations, allowing the body to translate along only one axis/direction. You require a joint that is a combination between a ball joint and a planar joint. You can do this by creating a 6DOF joint and constraining the one translation direction, or by constraining apoint to a plane -"general" joint.<?:namespace prefix = o ns = "urn:schemas-microsoft-comfficeffice" /><O></O>


Hope this helps,<O></O>


Kaz<O></O>



Edited by: Kaz Z06

 

[jayanta.diff]

U can do it by two simple steps as i think. just make two curve around the sphere and then make two cam connection with te base. hope it will work. But u suld take care of making curve as much as required for inclination.


Jayanta Sarkar


Application Executive


RHS Engineering Services


www.rhs-services.com

 

[Kaz Z06]

UnfortunatelyJayanta's suggestion will not work. A cam connection restricts motion to one plane. The two curves used to create a cam pair must lie in the same plane and be expected to operate within this same plane. If surfaces are used then the motion is restricted to the plane perpendicular to the extrusion direction for both of these surfaces. Therefore, it is not possible to provide the proper range of motion even if you create a second cam pair perpendicular to the first. My previous suggestion provides the only three methods I believe are possible. To clarify this further, the combination joint of a ball and a planar must be done with 3 bodies in order to provide the proper motion - the first "motion" body is connected to the "ground", or flat plate, by means of a planar joint. The third body must then be connected to the second with a "ball" joint. You will not be able to resolve directions using a ball joint, so if this is important, your only choice isto use a 6DOF with one translation constrained by a motor or joint limit. 6DOFs track all translation and rotation degrees of freedom and allow you to create measures of motion and loading in all 6 DOFs. The 6DOF lets you connect just two bodies to provide the desired motion. The point on a plane "general" joint will allow you to resolve results in only the two translations, so this may not be desirable either but will provide the proper range of motion between just two bodies.


Regards,


Kaz Z06