Did you print the pattern full sized or extrapolate it from your scaled drawings?  I have done that with Onshape and it works well.  IIRC, I printed a 1:1 drawing to a PDF and used Acrobat to print it page by page.  There is an option to add cross hairs when printing to paper for aligning the adjacent printed pages.  

--Nathan, TX. Hire the lazy man. He may not do as much work but that's because he will find a better way.