SB-250 blackstone update

[Ken S]

I bought my SB-250 blackstone in 2010, soon after it was introduced. I must admit that I have never really made nice with it. I know sharpeners I respect have had good results with it. I did not. It quickly glazed and stopped cutting for me. As a result, it stayed in the box. I have always suspected the problem was my technique, rather than the blackstone.

I have a standard test for evaluating grinding wheels. I place a metal lathe bit in the square edge jig (just like a chisel) and grind away for a timed five minutes. The results have been interesting. (I eyeball the removed metal. Incidentally, I set the jig to a thirty degree bevel.)

The "hometeam favorite" Tormek SG -250 or 200 does surprisingly well with the hard steel alloy on the metal lathe bit. The all time champ is the 46 grit Norton 3X wheel. It was turbocharged and maintained the water cooled, dust free Tormek environment. (The T4 is ideal for this; the 3X wheels are eight inch diameter.) The Norton 3X 80 grit wheel was a fairly close second. The 80 and 180 grit CBN wheels both did well. The lone poor performer was the SB.

The poor result bothered me. Several sources, including replies to a forum topic I posted, led me to believe that I was using too much pressure. I finally retested the SB, this time using a much lighter touch. Results were much improved. My faith in the SB has been restored. I still do not feel I have mastered it, however, I am inspired to continue using it.

Still growing,

Ken

[loutent]

Hi Ken - good information - I took delivery of an SB-250 just yesterday so it looks
like I have a learning curve ahead of me.

Lou

[Ken S]

Lou,
I wish you a shorter path to success than I had. I think light pressure is the key for the makeup of the stone.
Please keep us posted on your journey.
Fortune favors the brave.
Ken

[RichColvin]

Gentlemen,

I use my SB stone on my HSS lathe tools in the horizontal position for everything except the skew and scrapers.  Those get a vertical grind.  I find this works wonderfully. 

Rich

[Ken S]

Rich,

You are one of the sharpeners who has kept my faith in the blackstone alive when my own results were sub par.

Ken