Re: [CAD_CAM_EDM_DRO] Re: Scraping

Chris Stratton wrote:

> Since scraping has come up, I'm wondering if anyone could comment on
> how one scrapes the inside-slanted surface of dovetails?

You use a straight edge that has a wedge shape, so it can get under the
dovetail to mark the whole width of the surface. Then, you use special
scrapers that are made to be able to get all the way back in the corner
without gouging the opposing surface.

One of the secret tricks (from the Edward F. Connelley book) is to use
two precision ground round bars that you lay in the dovetail, and mike
across the two bars. When you get a consistant reading from one end
to the other, then the angled part of the dovetail are a constant
distance apart.

> I was thinking this
> morning that if I ever finish getting the ballscrews on the lathe, it
> might be nice to make some provision for mounting a mill head on the
> ways and clamping work to a larger, T-slotted cross-slide. This would
> require milling and then scraping a dovetail way.

Once you have the long set of ways scraped true, you can use that as a
master to scrape the sliding carriage.

Jon