Get the auto increment id of replicated record in laravel

I am trying to achieve something very simple. I have a datatable and I am allowing users to create clone of a record and open it in edit mode.

My controller is as below.

public function clone($id)
{
    $inventory=Inventory::find($id)->replicate();
    $inventory->save();
    return $this->edit($inventory->$id);
}

I was hoping to get the id of the cloned record from $inventory->$id, but it still gives me old id. But when I check in DB its generating a new id.

via Chebli Mohamed