So for those confused,
The above image is how you would want to setup a custom shipping carrier.
In this example, it is set for weight: 0 to .25lbs will charge customer $2.61, .25 to .5lbs will charge $2.75, etc...
You will also notice out of range behavior is disabled. This means that if the order weighs more than 1lb, this carrier will be disabled and they will choose another carrier. (for example, usps first class only goes up to 13 oz and then you need to use priority mail for heavier items).
If you wanted free shipping in this manner, then you would change billing according to price, you would set the >= $Free Shipping Amount ($50) and < $Some really big number (10000). Then you would put 0 instead of the 2.61 we have in the example and wallah, you have a free shipping options.