This is my modular Motor Factory made with 2 alternate recipes (Steel-Rotor, Iron-Wire).

Input: 78 Iron Ingot per Minute, 50 Steel Pipe per Minute Output: 5 Motors per Minute

I left the front open so I can expand it on the backside. Just place it right on the backside and connect the belts. I recommend to fill all resources at once before switch on. Especially Wire. Otherwise it will take a while before it works on 100% and Maybe the Rotors will Overflow. For this reason I have an Overflow-Splitter on the top but it wasn't necessary yet. You can switch it to Copper-Wire too but for me it was important to make the Motors just with Iron and Coal.

I'm not an artist. So feel free to make a beautiful facade at it.