Scraping sound

There are a few, but not many I think, that require a scale. You are correct, and I agree, that most tonearms I have seen have a built-in scale of some sort for adjusting VTF

I've recently experienced this unpleasant sound. In my case, the cause was a defective motor housing.

I always set my VTF using a scale. There is too much variance in eyeballing to be 100% certain the arm is initially “floating” perfectly horizontally. The older I get, the less I trust my eyes for geometric challenges. On the subject of scales, the good old fashioned balance scales never go out of calibration unlike electronic scales with sensors.