Again, you did not create an object of your custom_model class, with the last thing you added you now created a function which name is custom_model, which returns null. Then you are returning this function from getArmorModel, so that in the end getArmorModel returns null...this way your armor will never show up, so delete the last line of code you added and listen. To instantiate (create in other terms) a custom_model object you need to use new custom_model(a_float_value) , where a_float_value, as i said above, is a float number. Forget about caching at the moment...