CSG modelling on ROBLOX is still in its relative infancy. Things will get better as time progresses, so for the moment it's just a waiting game.
In regards to unsolvable unions, there are a number of ways around this.
* Try working at a larger scale and then shrinking the resulting union down.
* If you're trying to union multiple things at once, attempt doing it one at a time instead.
* Don't use weird positions or rotations. |