As my title says. Who makes them, or can they be done via spare parts. It seems that if they stop manufacturing light sabers to their enemies, they would then have balanced the force.
There are no Lightsaber manufacturer company which makes profit by selling Lightsabers. Lightsabers are almost always constructed by the wielder to match his or her specific needs, preferences and style.
In fact, Lightsaber construction is mandatory skill of a trained force user which can be seen in this dialogue (from Star Wars Episode VI: Return of the Jedi):
"I see you have constructed a new lightsaber. Your skills are complete. Indeed you are powerful, as the Emperor has foreseen."
- Darth Vader to Luke Skywalker
There are some rare cases, however, in which a wielder uses a Lightsaber constructed by others:
- Luke Skywalker initially used a Lightsaber constructed by his father Anakin Skywalker which he lost to Darth Vader (along with getting his hand cut off).
It was hobby of General Grievous to steal Lightsabers of Jedi & wield them.
In the animated series Clone Wars (2008) there is an episode where Ashoka Tano takes young padawan to Illum where Master yoda instructs them how to get their lightsaber crystals. The Gathering The very next episode shows those young padawan trying to make their lightsabers by using the Force and a whole lot of components. A Test of Strength