Some videos showing how you can work on your drawings without a T-Square or Mayline
(Rolling parallel ruler if interested: https://www.amazon.com/Alvin-312-Rolling-Parallel-Ruler/dp/B001VT7J2G or https://www.amazon.com/Acurit-Rolling-Measuring-Drafting-Drawing/dp/B00488B4NM/ref=mp_s_a_1_4?dchild=1&keywords=drafting+rolling+ruler&qid=1585785533&sprefix=drafting+roll&sr=8-4)
