Stone Grader SP-650

[Ken S]

Darryl,

Take a look at the forum stats.  Your post has generated the most replies in the history of the forum.  In fact, more than the next three combined!

Good job!

Ken

[Steve Brown]

I live in Colorado, I don't think I'll be seeing you boys anytime soon. That's funny, I didn't realie they had electricity in Canada.
Steve

[Ken S]

I just modified my TT-50 jig following Ionut's suggestion.  The bounce is gone.  Nice improvement, Ionut. 

Keep up the good work.

Ken

[ionut]

I live in Colorado, I don't think I'll be seeing you boys anytime soon. That's funny, I didn't realie they had electricity in Canada.
Steve

You are right we don't. I had to take my bike apart and adapt the pedals on the Tormek in order to make it work but now I realized that's also the reason why I always end with the perfect edge on my tools.

Ionut

[Steve Brown]

Ionut,
I have to admit, you guys are extremely clever. Do you think Tormek will modify the TT-50? Be interesting to see if there is a reaction to these posts. Keep up the good work.
Steve

[ionut]

I believe that question would be for Jeff to answer or Tormek engineers. Personally, I think the economical aspects of changing the production line to make larger holes in the diamond head housing and fit it with tight tolerances plastic or metal bushings compared with the 5 cents/tie or whatever would be the price of one, may be the reason to not change anything but you never know.

Ionut

[glh17]

I live in Colorado, I don't think I'll be seeing you boys anytime soon. That's funny, I didn't realie they had electricity in Canada.
Steve

You are right we don't. I had to take my bike apart and adapt the pedals on the Tormek in order to make it work but now I realized that's also the reason why I always end with the perfect edge on my tools.

Ionut

This guy ought to try a Tormek.
http://www.youtube.com/watch?v=9bx_PkNIfK4&feature=related

[tooljunkie]

I m also from Canada not far from Ionut (across the pond)

Here is how they sharpen knives in Iraq

http://www.youtube.com/watch?v=BH92ZpBDlk0&feature=player_detailpage

http://www.youtube.com/watch?feature=player_detailpage&v=nuxwGY6TY_k

[glh17]

tooljunkie,
I'd like to see the burr on the iraqi's knife.  I guess the driver would have to take care of the other side or maybe put it in reverse.
glh17

[Steve Brown]

I like Ionut's bicycle method best, but the Iraqi's approach makes me wonder about the repeatability of those results and also how do they gauge the grit size of the asphalt. There must be a lot of variation from road surface to road surface. And of course, in Iraq you have to constantly be on the lokout for contamination due to road kill as well as pitting of the sharpening surface from suicide bombers. Lucky we have Tormek.
Steve

[Steve Brown]

Just looking at your stone for the first time, right out of the box, let's say, is there a way to tell just by looking if it's been graded to 220 or 1000?
Steve

[glh17]

Steve,
I can tell by feel now that I've used the stone quite a bit.  But, if I just opened the box I don't think there's a good way to tell.  My tormek is always dressed and then stored with the 1000g grind because that's what I use most often.  I will touch it up with the grader prior to using it.
glh17

[Jeff Farris]

By looking? No.

Out of the box it is 220.

Here's the thing with the grader and the grading process. That grindstone is 220 grit through and through. The stone grader is an abrasive that is harder than the grindstone. When you use the stone grader to create a fine cutting action you are creating an artificial surface and one that is very, very thin. The 1000 grit finish is a few thousandths thick. Below that, the stone is 220. If you wear through the 1000 grit, the stone will start cutting more aggressively. In flat work (chisels and plane irons) it is rare to wear through the fine surface, but with turning tools, carving tools and knives, a very light touch is needed to keep from exposing fresh abrasives and going to a faster cut.

The sensory tools you need to determine the cut are your ears and fingers, not your eyes. There's a very distinct difference in the sound of the cut when the grader has been used properly (in either direction). When grading the stone to cut fine, it should feel like a piece of wet glass. If it feels abrasive, you haven't used the grader long enough. Going to coarse, the surface should feel much like a piece of 220 grit sandpaper, if it feels slick, it won't cut the way you want it to. This is also true while using the 220 grit...the steel tool is going to dull the crystalline edges. If it doesn't feel like it can cut, it can't and you need to refresh the surface with the coarse side of the grader.

So, you may ask, if the tool is going to make the grindstone smooth, what is the grader for? That would be an excellent question to ask, and one that leads to a discussion of abrasives.

A dull abrasive that is larger is not the same thing as a sharp abrasive that is smaller. Think about it with wood. A piece of almost worn out 100 grit paper removes about as much material as a fresh piece 220 grit paper, but the surface is decidedly different. The worn out 100 grit leaves a burnished, irregular surface. The sharp, fresh 220 grit paper leaves a uniform scratch pattern and no burnishing. So, in the case of the Tormek SG-250, a stone that feels slick from use (glazed) will not cut the same as a stone that has been graded with the smooth side of the stone grader.

Tormek owners that watch me work are constantly surprised at how much I use the stone grader, and are always asking me why I'm using it. The simple answer is, I'm getting the machine ready to do what I want it to do. I just naturally assume it needs grading to do what I want it to do, no matter what that is.

[Jeff Farris]

Here are the pictures I've promised about the workaround for the TT-50.

Thanks,
Ionut

The images have to be uploaded on the internet with a unique url. You linked them to the location on your hard drive. I uploaded one to my company server. Here it is. Below the pic are my comments.



I tested this this morning and found no advantage. I'm not sure what you guys are doing, but I'm going to guess that you're moving too slow. Any vibration I've ever experienced could be eliminated by increasing my traverse speed ever so slightly. All this did was make the knobs harder to turn. Another thing that minimizes vibration is to cut from the outside in rather than inside out (mandatory with the T-3).

When the TT-50 was developed, the first prototypes had a much tighter fit. Within a few uses, the tool would not advance whatsoever. This modification has no negative effect as far as I can tell, but I didn't see that it improved the finish on the stone whatsoever.

[ionut]

Hi Jeff,

I know the link was on my machine but I have no means to deploy a picture on your server I should have probably used the free email sites providers that allow picture uploading but I have no web space created for that purpose. That would mean that whoever wants to load a picture has first to upload the pictures on an internet server.

On the Tomrek Japanese stone regardless how fast you go it will chip the exit edge of the stone badly, I usually take very small cuts not more than 1/12 on the adjustment wheel and whenever I've done that I chipped my stone. It does not happen as bad on the 220 stone, but my Japanese stone still has some of the chips created with the first truing.
On the 220 stone there is a different story, if I use the TT-50 as it is at the max 90 seconds  truing speed it the grinding surface of the stone is full of ditches and even though that does not affect the cutting I do not like the surface left on the stone and more than that when such a surface needs to be graded to 1000  takes a longer time to bring it there.

Thanks,
Ionut