I found this article on how to make and use a simple Do It Yourself vacuform machine. It is geared mostly toward radio controlled aircraft parts, but the same is used to make canopies and other parts we use in our paper model hobby.
https://www.modelairplanenews.com/va...EDe7B0VlZ9W62w
This is not the only article and many others posted their own versions on line.
Isaac