I normally click many times on the 3 just to be sure, because when you have many objects your simulation is much slower. When you save delet trails, impact marks and will reduce the size of your simulation.if you don t do won t save. Wait at least a universe sandbox year to put back dust and impact marks. PS don t forget to desactivate dust, trail and impacts marks at the start.if not your universe sandbox will crash.then bye bye to your work.

And i continu like this until i m satisfied. I normally put 2 objects of about the same mass on the same orbit but 180 degrees from each others.so one is on the right side of the ''protostar'' and the other one is on the other left side. Dont put dense objects on it.more they are dense.smaller they are.so they ll be fewer colisions. Then for the disk (depend on your computer speed and power), put many objects in orbit, make them explode in 500 objects (select the average speed and the mass of the object).

Ex a 0.15 Sun Mass Star will be 0.15 Jupiter Mass Object. But reduce its size into a Jupiter mass object. First you need to put a center object mass like a M dwarf star, a brown dwarf and etc.