Question for the Sharpmaker experts (or just regular Sharpmaker users)

L

leozinho

Joined
Jan 7, 2005
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143
After sharpening on belts for a while, I pulled out my Sharpmaker.

Am I supposed to raise vertically the handle as I bring the blade down the stone when using the flat side?

Or am I supposed to keep the spine of the blade more or less parallel to the surface?

Or am I supposed to move the handle slightly away from the stone so that the edge remains in contact with the flat of the stone as I pass through the belly and to the tip?

If I bring the knife down while remaining more or less parallel to the table, then the knife's edge - starting at the belly and continuing to the tip - is only touching the edge of the stone. I think the angle of the edge also changes and becomes more acute if you use this method.

Depending on the length and profile of the blade, if I keep the blade perpendicular to the length of the plastic box, then I have to make an exaggerated lift of the handle to keep the edge in contact with the flat of the stone. I think this also changes the angle of the edge as you move through the belly and to the tip.

The other option would be to move the handle away from the stone as the stone starts to touch the belly and continuing through the tip. (Similar to the way most lift the handle when moving through the belly when sharpening freehand or one a belt.) If you do it right, this would appear to me to keep the edge angle consistent. '

To test this, I took a scandi grind Mora and kept the edge flat to the stone. Assuming the angle of the scandi grind on the Mora is consistent, then a slight lateral movement of the handle away from the stone is needed as you pass through the belly.

What to you guys think? I've watched a couple Youtube Sharpmaker videos and people don't seem to be moving the handle laterally. Maybe they are changing the edge angle at the tip without realizing it.

It's been a long time since I watched the Spyderco instructional DVD, but I don't remember this being discussed.

(Not really here nor there, but I see a lot of how to videos using a 1x30 belt sander on Youtube video where it appears many are lifting the handle too much. Of course, it depends on the blade profile, but it didn't take much lifting to keep the scandi grind flat on the stone. I see a lot of people really lifting that handle, which would make the edge angle at the tip less acute.)
 
That is a lot of words brah, and I am drinking.. but I am also touching up an edge on my sharpmaker now.

You need to hold the knife straight (0 or 90 degrees, depending on how you think about it) the whole way down the stone. The instructional video from Spyderco is on youtube, and I know fellows from here have posted it up as well (use the search function for sharpmaker). You don't move the angle of your hand at all, that is the point of a guided system like the sharpmaker.

Although if you are sharpening on belts first- that at least implies a convex edge- why are you going back to a v-grind? It is going to take a lot of strokes on a sharpmaker, even with diamond stones, to reprofile or establish the proper edge again.

Hope that helps.
 
Ken's video on this is the best explanation I've ever seen of why we rotate the blade as it curves.

https://www.youtube.com/watch?v=JFhUXgYS0Os

In summary, you need to lift the handle so that the spine stays parallel to the ground, but the handle lifts towards the ceiling. The idea is to maintain the normal line of the blade pointing towards the base of the sharpmaker at all times. In the straight portion of the blade, you don't need to do any adjustments; just pull down and back. When you reach the curved section, lift the handle enough so that the normal line (perpendicular to the tangent line), stays pointing straight down the SM rod.

Ken's video illustrates this better than my typed words. I think you'll get it after watching his presentation.

Brian.
 
bgentry said:
Ken's video on this is the best explanation I've ever seen of why we rotate the blade as it curves.

https://www.youtube.com/watch?v=JFhUXgYS0Os

In summary, you need to lift the handle so that the spine stays parallel to the ground, but the handle lifts towards the ceiling. The idea is to maintain the normal line of the blade pointing towards the base of the sharpmaker at all times. In the straight portion of the blade, you don't need to do any adjustments; just pull down and back. When you reach the curved section, lift the handle enough so that the normal line (perpendicular to the tangent line), stays pointing straight down the SM rod.

Ken's video illustrates this better than my typed words. I think you'll get it after watching his presentation.

Brian.
Click to expand...

Thanks for that. I've seen that, and that's the same thing I'm doing with the scandi-grind on my Mora. You can see exactly what you have to do to keep the scandi grind flat to the stone. It's the same up and away movement of the handle that people sharpening on belts or stones do. I guess I'm second guessing myself because I've seen a few descriptions on how to use the Sharpmaker, and I've not seen anyone making that 'away' movement.
 
jdavis shows pretty much how to do it here in this video: https://m.youtube.com/watch?v=-MHe_8wTHmg

However I think you should mark the edge with sharpie and see whether you hit the tip or not all the way. I do move the handle of the knife sideways at times depending on how much belly is on the blade and how long it is.
 
Ken (ksskss here on BF, kenneths123 on YT) showed the concept of keeping the sharpening angle when reaching belly to tip. It's the best explanation of what I have in mind.

He demonstrates with belt but the concept applies to Sharpmaker (vertical instead of horizontal).
 
Chris "Anagarika";13934533 said:
Ken (ksskss here on BF, kenneths123 on YT) showed the concept of keeping the sharpening angle when reaching belly to tip. It's the best explanation of what I have in mind.

He demonstrates with belt but the concept applies to Sharpmaker (vertical instead of horizontal).
Click to expand...

That's the video referenced in post #3. I understand that the same concept of moving the handle away from the belt should apply to the Sharpmaker. However, even though all/most of the folks sharpening on belts or stones do it and talk about it, but I don't see anyone talking about it with the Sharpmaker. Which is why I started second guessing myself and came here for validation or to be told I was doing it wrong (and why.)

(On the video in post 5, it looks like the person might be doing it, I can't tell.)

I think the difference is negligible on short blades without a lot of belly. On larger blade with a lot of belly, you would see a difference. If you don't move the handle away from the sharpening medium, you are going to create a more acute sharpening angle at the tip (and on the Sharpmaker, with the not very aggressive medium stones, you probably aren't going to reprofile the edge enough and won't be hitting the apex.) At least that's how I see it.

The beauty of the Sharpmaker is that you only have to be able to keep the blade vertical in order to be consistent and produce a fine edge. The technique I'm experimenting with, I still kept the blade vertical, but I do have the added motion of moving the blade handle horizontally. But, there's still a visual reference. I just move the handle horizontally enough to keep the edge in contact with the middle of the stone. It's a very easy visual reference.

Thanks again.
 
I'm glad you posted this because I have had the same question. I have had my Sharpmaker about a month. Before that I sharpened on stones. I have not seen it mentioned, but on a stone you have to raise the blade at the belly to tip, so on my Sharpmaker I move the handle of the knife away from the stone when I get to the tip and belly. Works for me, keeps my bevels even.
 
awestib said:
Not sure that I understand that movement ??
Click to expand...

I didn't explain myself very well. I was trying say that the way I use the Sharpmaker by moving the handle of the knife away from the stone at the belly and tip of the blade - is similar to raising the handle of the knife when sharpening on a flat stone. Like the OP, I have wondered if this was the proper way to use the Sharpmaker, but little could be found on the web to answer that question.
 
I'd say raising the handle on a flat benchstone will work, as I have tried it before. This method is recommended by HeavyHanded.

On a sharpmaker, Ken's method should work better, i.e. raise the handle vertically so that the edge angle is maintained by keeping the blade/plane always vertical.

I use Ken's method even when sharpening on flat benchstone (washboard in this case).

At the end, it's back to individual preference. To me, Ken's method is easier to visualize & follow. I have not tried imagining the plane / intersection / angle resulting from HeavyHanded's method. Maybe one day will do that, using a coin (representing the belly) attached to a ruler (representing straight edge)
 
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I just watched that video. I'm trying to explain exactly what he said, just not doing such a great job at it. But once again, this thread has been a great help, I feel like what I've been doing is correct.
 
Thanks so much for this thread guys. I have been wondering about this for a while as my Bellies and Tips are never as sharp as my straights and there is little information about it out there.
 
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