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mechanism - Ball&Socket

jgray_globus

New member
I have a basic Ball & Socket assembly. I need to control the angle of the top piece not to ever be greater then, lets say 10 degrees from center. I have gotten the assembly to tilt to to 10 degrees. I need to then spin, in a conical motion, around the Axis of Revolution. The Ball & Socket has to maintain contact. I have gotten it to revolved around, but the part also spins. It has to remain a front to back relationship with the bottom part.


Thanks for the Help


Jason
 
No recommendations!!!! This is driving me crazy and can use this for multiple situations. ANY HELP would be APRICIATED!!!!

thanks
Jason<?:namespace prefix = o ns = "urn:schemas-microsoft-com:eek:ffice:eek:ffice" />
 
I would model the connection as a universal joint with two orthoginal revolute (pin) joints. This way you can control the rotational limits.
 
I am not sure that is going to get me what I need. Will that allow the ball and socket to remain in contact at all times. There is compression on the 2 parts, So they will not be able to seperate.


If I use a ball connection. Is there a way to contrain it so the arrows are always pointing bact to back? And also contrain it with angles in each direction. Really since it is a ball & socket, it would be one angle.


Any other thoughts??
 
So I will have 2 pin connections. 1 front to back & 1 side to side. Can I have them on the same plane? I tried that and the model is locked. If I disable one, it allows me to move it in a planer motion. I need it to have full range of motion with some controlable angles. If I add a axis at a different plane, will this then allow more movement??


HELP !!!
 
You may need to introduce a "dummy" part to bridge the two pin joints. Base to dummy with one pin and dummy to post with a pin in an orthoginal direction. This is effectively a universal joint.
 
Hi,


Here is the solution.


When assembling, initiallygo for a ball joint between the two components. Then go to mechanism design, and apply cam connection (Lift off enabled) beween the two components. The cam connections is to be applied to the flat surface of the ball (in the assembly you uploaded) and the edge of the curved surface of the socket. The final mechanism tree will be as shown in the figure.





Regards,


Shankar
 
Yes that works. I thought I used 2 cam connections(one each side). But besides the point. I did this very thing and this controls the area of motion ok. I would really like to control the motion by a angle. If everything was in line vertically. Ball and socket were perfectly vertical to each other (one of my pictures show it). I need to tilt out 8 degrees (one of my pictures show that also). Then I need to rotate around the still vertical axis of the ball. I really need to control the angle!!! One last thing to throw in the there. You know tha set of arrows on both parts. They need to be allows pointing to the front and back of the part. They can't twist !!!


Thanks for the efforts, I hope you come up with something. I have contains this in standard mode by using a few datum planes, curves and points. Can get it to go through its motions in the correct orientation.


Jason
 
HAI JGRAY


i think you need to assemble the green part using planar connection first and then add two slot connection along the red part's ball curve see picture. with this you can control its angle during analysis by tabular motor values. is this you want to achieve?
 
I am not sure if this will allow you to revolve the green part around in a conical motion.
I believe this only allows motion in 2 directions. Tell me if I have misunderstood you.
Thanks
Jason
 

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