Scraping basics - Scraping flat - Part 2

It's a good skill to have - I mean it's nmot required very often - but if you ever see a small team of 1 - 3 guys restoring the slides on a lathe or milling machine... It's pretty impressive. I have seen it being done perhaps only once or twice in my whole life.... and I only restore the flat faces on small motor parts, using thick plate glass with a bit of carborundum paper clipped to it - in assortedly finer and finer grades... But knowing how to level the face evenly is an art form too... Do you repair parts / motors and all that?

I'm in the electronics test and measurment business. But i've been considering reproducing rare and sought after 90's mtb aluminum parts for a long time!