Depends on what machine you want to boost ...
Its it single or twin vac , series or parallel ?
An inline booster would be tricky to fabricate as u have to build a waste tank ith fittings ....
Better just buying one id say , as mentioned above the Mytee with APO would be great

A series booster ( connected to the vac exhausts ) could just be a motor in a box / toolbox .... or better still if boosting a twin parallel machine ... two motors in a toolbox
i do that but as hector said i want one that hovers

guess i will abandon idea as i do not saw straighr