Our video showing how to evenly balance the load on a single conveyor in Factorio.
The example pair on the left of the video can take an uneven belt load and balance it, regardless of the distribution of the incoming belt. The pair shows how to make the balancer in a straight path or with a 90 degree turn.
The pair on the right is more compact, but also more specialized. It only balances an uneven load if the incoming load is entirely on one side or the other. It will still allow objects to pass if they aren’t all on the same side, but your resulting load will not be balanced.