I am trying to learn violin using online resources only. After about 80 hours of practice I destroyed a bow eyelet. My guess is that I applied too much tension on bow hair and/or bow quality was low. After buying a better student bow (and some spare eyelets) I started to use low bow tension just to avoid similar problem in near future.
What range of violin bow hair tension is generally accepted? What tension is good for an eyelet?
The first thing to note is that you should slacken off the tension when you finish practice before you put the bow away to avoid long term damage to the bow and stretching of the hair.
Before practicing / playing you should tighten the bow. The usual guideline is that you should just be able to pass a pencil between the hair and stick. The bow has a built-in curve with the ends of the bow further away from the string than the middle. You should under no circumstances tighten the bow so much that the stick ends up in reverse camber with the middle furthest from the stick (unless you are using a baroque bow which starts off in that shape) and it is unwise to tighten so much that the stick loses its camber and becomes straight.
As a beginner this is all you need to know about bow tension. As you get better and perhaps want to play strokes where the bow bounces off the string you may want to increase the tension slightly to make this happen easier but still, never so much that the bow loses its camber. Before you get to this stage you will likely need a better bow which can support greater tension.
I can't count the number of times I've said this: you must get a teacher. Online learning will never work as well, because of issues like this. There's no "feedback" to tell you if your hand positions are correct, your bow angles are correct, your bow pressure and speed are correct, and, yes, your bow tension is proper.
You shouldn't even be able to damage the eyelet! I'm a bit surprised that the hair hadn't snapped off the tip first. Please, please consider at least the occasional lesson, even via video conference if necessary.
