How to make straight mines?
Mining through a mountain, I see that, unlike Minecraft, it is very hard, on Medieval Engineers, to make a straight mine without some aid. But I don't know which aid I could use.
Masons/bricklayers use some lines to ensure the bricks are all aligned on a straight line. I believe this technology already existed on Medieval Ages.
How can I do this? Or is there a better way to ensure that I'm not making a circular cave?
Cheap Planks will do the trick, as they can only be rotated 90º: