Hey everyone
I’m trying to make a simulation where objects move in circle while floating in the air and colliding with each other.
The problem is that I can’t make them move without attracting towards the center. I tried to use the vortex force, but it attracts the objects towards the center, while I need them to stay the same distance out of the center.
also is there any way to make them move with the different speed?
Instead of using a Vortex, use a Curve Guide 
You can check Cyclic in its params to make it a loop
Yes, in the particle emitter param, velocity tab, you have the initial velocity and the randomize param, set randomize to something above 0. to add random (If you put velocity for example to 20, and random to 1, velocity would be from 0 to 20. If random is .5 velocity would be from 10. to 20., etc…)
See you ++
Tricotou
Thanks for the answer.
Your solution works with particles. But unfortunately not with rigid bodies.
Just in case I’m using blender 2.8
If all else fails you could spawn all of the objects behind an invisible wall obstacle. It is a bad idea and doesn’t really fix your problem but it would keep the objects at a minimum radius from the centre.
However, I recall the Magnetic force field never pulled objects towards it for me, but instead made them all circle around it in various arcs, like gravitational pull.