The rear spring on a standard tattoo machine has to be bent
(according to most tattoo artists), at least to some degree. This
is considered a major flaw in the age old design of the armature
bar. It is because the armature bar is perfectly level on both
sides that this is required. If the armature bar was milled out
at a slight angle on the rear side of it, then the bend would not
be required. This is actually being focused on by several a-bar
manufacturers in the world today. There are different styles of
a-bars available that have a slight angle milled out. This is really
exciting because you take a large variable out of the guesswork
of tuning the tattoo machine, “the bend”.