what is the best condition for a commutator
a light straw
b jet black
c dull copper
d chocolate
i choose chocolate as we want to see a good commutator film graphite plus copper = brown
jet black was another possibility
dull copper would mean that there was no brush contact or it was new
light straw same as above
i have asked experienced electricains and motor builders who told me they would have picked jet black,dull copper and even shinny copper?
what do you think??