Hi I need to design some basic models of an open channel (basically a long 3 sid

Hi I need to design some basic models of an open channel (basically a long 3 sided box.) with a side weir (basically an open space) with differing dimensions in AUTOCADD.There are a total of 19 models to be made but since they are all similar with minor tweaks in dimensions it is quite easy to do the rest after the first model is made. I have attached the instructions and also some models which i have already done. These models are very similar in dimensions (channel is standard size just differing side weir dimensions) so you can just use them and tweak them to the dimensions that I am requesting for.Please note that i require all this models to be sent in individual files and in .stl format.Thnak you in advance.