/3/ - 3DCG

how can I make a model and 3d print it so it fits? I made an airsoft mag (non functional) but the first print didnt fit bcs it was too large, so I tweaked my design and printed it again. now it is too small and falls out on its own. every attempt takes a few hours so I'm fucking mad at that retarded technology and at myself bcs I can't apprehend it
picrandom