- May 25, 2010
I started with checking the horizontal surfaces on the surface plate using a dti on a guide block, it is difficult to measure scraped ways directly. They checked out perpendicular, al the other ways showed very little wear. From there I checked the y-axis for flatnes and started taking the high spots down. There was no real high/low side on the ways so I just started Scraping. In the beginning I used an HSS scraper which doesn’t do much on the cast iron ways, in the end I used a carbide scraper but still with a large radius. Most important was to keep the y-axis paralel. I would not use this approach if the wear was on more surfaces as it would require getting Everything back to square. If you look up “this old Tony” on YT there is a series of videos where he works on a surface grinder bringing It back to square.@waiting for time, question for you on scraping the mill. How do you ensure your x and y ways are parallel to each other, and your z ways are perpendicular to both of them? Scraping with the surface plate as a reference obviously produces individual flat surfaces, but how do you check that the different flat surfaces are parallel/perpendicular each other? Is the flatness tolerance of these machines just so much tighter than the parallel/perpendicular tolerances that you don't really have to worry about affecting their parallelism/perpendicularity when you remove material to make each surface flat?
Hopefully my question makes some sort of sense. I've been researching building precise machines recently, and it's been very interesting, but creating flat surfaces that are perpendicular to each other via scraping is something I still don't understand.
Thank you for sharing your work. You are putting together a very nice shop there!
In the end you just need to start easy and learn as you go.