wiliam yes i have seen this links regarding books to buy , i cant find any contact beside why shall i build my own , and how i expect to work better if gb comapny seems they know much more how to build righ machine . You ask how many wats gb4000have , please check by yourself , i am here to hind an answer not to get you answer . One more time i will say cancerturor recomend it this machine as the closer one ro royal rifle if they are wrong tell me why