Author Topic: MB-100 Tests  (Read 723 times)

Offline RichColvin

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MB-100 Tests
« on: November 12, 2018, 02:37:42 am »
Today, I had to resharpen a standard old chisel (after finishing up some honey-do items).  This chisel doesn't have much sharpening life left.  In fact, I was not able to sharpen it to 25ยบ in the traditional manner when mounted in the SE-77 jig (or even the older SVH-60 jig).  The only options traditionally were:
  • increase the angle, or
  • buy a new chisel.

Fortunately, we now have a third option: the MB-100 Multi Base!

So today, I took this fortunate opportunity to test the MB-100 Multi Base (and diamond grindstones) that Ken Schroeder so graciously loaned to me. 

The results of using the various grindstones are below.  Please ignore the burr on the edges :  the pictures are simply to show the faces after use of differing grindstones.




This tool was then sharpened on the SB and SJ grindstones (still using the MB-100 ... with the same setup). Mainly, I wanted to see how well it would work.

SB-250 - Graded Course

SB-250 - Graded Fine


Then the angle was increased to allow for a micro bevel.  This worked quite well !  (The micro bevel is quite a bit bigger than normally put onto an edge, but this enabled the picture to show well.)

SJ-250 - Micro Bevel

And finally, the tool was honed on Razor Sharp paper wheel.  (Yes, that's the iPad's camera reflected in the edge.)

Honed on a Paper Wheel

My take-away is this :  Whether using the diamond or traditional grindstones, the MB-100 is a worthwhile investment.
Rich Colvin - a reference guide for sharpening - help those getting started in ornamental turning -- to make that journey easier.

You are born weak & frail, and you die weak & frail.  What you do between those is up to you.

Offline Ken S

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Re: MB-100 Tests
« Reply #1 on: November 12, 2018, 08:57:10 pm »

Interesting tests.

It took me a while to get my brain oriented with the scratch patterns. I'm accustomed to scratches going perpendicular to the ground edge. Of course, your scratches are parallel with the ground edge; you are grinding with the side of the wheel.

I liked your including the SB and SJ in the tests. I realize Tormek only recommends the diamond wheels for side grinding. However, is your test really any different than flattening the backs of chisels, which we have been doing for years with the original grinding wheels?

From your test pictures, it looks like the DC-250 cuts more aggressively than the SB-250 graded coarse. Is this what you observed?

The scratch patterns from the DF-250 (600 grit) and the SB-250 graded coarse (220  grit) looked similar, the DF being perhaps more distinct. Would you agree?

The DE-250 and the SB graded fine also looked similar, again with the DE scratches appearing slightly more distinct. Yes?

Naturally, the SJ and the paper wheels led the pack for smoothness.

As a longtime turner, you do much more heavy grinding than I do. Your BGM_100 and dry grinder combination for reshaping makes perfect sense. For the little heavy grinding that I do, the DC-250 is a welcome time reducer. It is still no speedster, however, it makes reshaping a more pleasant chore.

While reshaping my skew, I came upon a technique which might be useful for short chisels. When the support bar is placed almost next to the grinding wheel, it becomes a platform which can work with very short blades. It does not have the precision of a jig, however, with care, it should be adequate.

I welcome different points of view. Keep up the good work!