We have been using Ultimaker2+ for 7 years. No major problem and our kids also love its outputs. Recently I noticed that its way of leveing build plate can be used for leveling lid heater of qNinja.

Here is the result. You can adjust lid heater by screwing 2 Double Step Thumb Nuts. They are hot while PCR process so top wooden board will hide them. Top board is holded by 3rd nut on top-left corner. When top board is removed, front board also can be removed so that you can check the level of heater while adjusting.