Sharpmaker is flawed from manufacturer

[Forgetfull]

I own all 4 different stones ( UF, white, brown, diamond)

I’ve always wondered why my sharpmaker never seemed to get things as sharp as I thought it should. Moving stone to stone seemed like back peddling in sharpness occasionally, sides to flats felt like the angle was changing or not cutting. I thought I was digressing in skill. Turns out the problem wasn’t me.

I’ll try and be short but technical. Basically- the angle varies depending on what grit you’re using, what stone you’re using for that grit, flats vs corner of the stone, different sides of the stones, and even the 2 holes in the plastic base on the same side.* I can’t believe I didn’t notice this sooner, I always had my doubts and felt something was off but dismissed my concerns. I’ll explain why the angle changes.

I measured each stone and grit with a caliper and they all were “significantly” different widths, and even some stones (especially the diamond) had different widths depending on which 3 sides you used.

Therefore when the stones are sitting in the plastic base the skinnier stones (or side of a* stone) have more room to spread out and this creates a greater cutting angle on the knife edge. How much of a difference? 1-2 degrees as measured by a protractor, and yes it’s very noticable. I verified this by accident using the diamond stones on a new knife the other day when I made the discovery. I was shocked to see that between the flats and corner it looked like a quasi-microbevel. So I measured them all with a protractor and verified. Now if the angle difference was consistent you could easily compensate for it but every stone is different and every side is different.

Here’s a link of 2 rods superimposed on eachother

http://lh3.ggpht.com/-wFyc5xxLcxU/Scpu3PVcxmI/AAAAAAAAA9Y/-xy-sEtPnxs/s2048/Superimposed.jpg

How do people still get very sharp knifes? Sloppy technique and many repetitions will end up getting you a semi convex edge and still a sharp knife. At the expense of time, more metal removed, inconsistency, and edge smoothness. But as consistency and technique improve you’ll actually have a harder time using the sharpmaker since you’ll be not sharpening the same angle anytime you move/change a stone. IMO that makes it a glorified freehand bench stone. If Spyderco just made the stones with tighter tolerances so the angles only varied 0.5 degrees between stones I’d have no complaints.

I’ve heard of people wrapping the rods or pulling them together to remove the slop, but this just creates the same problem except not the loose rods form a more acute edge than the thicker ones, plus this still doesn’t account for inconsistency between sides on the same rod.

 

[Obsessed with Edges]

The true key to making best use of any sharpener is in developing a feel for when the bevels are flush to the hone, and the feel for regulating pressure, regardless of what the pre-set positioning angle is. It's no surprise there's some variability in the Sharpmaker's setup; but, it's basically moot, as there's always (always, always) even more variation in the user's own hands. Even if the static setup guaranteed the rods were always at the same exact angle, the end result would still be essentially the same, UNLESS the knife itself were also held & driven by a completely accurate & steady mechanism, which human hands will never be. The variation would be a problem if the system was intended, designed and built to work completely without any direct human control, but it isn't. It's also not priced with that in mind. There's no such thing as a flawless $60 sharpener, from any manufacturer.

The Sharpmaker is designed to make it relatively easy for a complete novice to attain (at a minimum) respectably sharp and useful edges; and even then, with some thoughtful and careful practice. A variation of 1°-3° is still much tighter than most novices would get using virtually any tool; many amateurs would do much, much worse in using a regular stone, without any prior practice or real knowledge of what they're doing. The better one gets at developing the feel for finding flush contact (which is always the same, no matter what system or tool is used), the better the results will be on the Sharpmaker or any other tool.

What makes the SM or any other V-crock system more useful, in most cases, is the setup which positions the hones to use a stroke that's essentially identical to the 'normal' slicing motion most often used when cutting with a knife. It's a motion that's oriented vertically, and which positions the hand in a comfortable orientation for holding and using the knife. That lends better control and accuracy when sharpening, because almost everyone already instinctively knows how to slice with a knife. The Sharpmaker is still a free-hand sharpening tool; it's just that it's design makes that 'free-hand' stroke a little more intuitive to use, for most people.


David

 

[Twindog]

I just tested my Sharpmaker with different stones using and AngleCube.

Both the table and the sharpening base of the Sharpmaker were 0.0 degrees.

White stones (left and right): 20.85 degrees and 21.15 degrees.
Brown stones: 20.4 and 20.9
Extra fine stones: 20.7 and 20.5
Diamond stones: 20.2 and 21.0
Congress 320 Ruby: 21.7 and 20.5

I'd guess that my ability to hold a perfect vertical angle while sharpening the blade would produce more variation, but there is variation in the angles of the set stones.

 

[Threethreethree]

I recently lapped several rods and ceramics and also noticed how some were warped and very far from true, while at the same time i used the 204 for a decade and got decently sharp edges with little fuss as long as you use it as a microbevel tool and avoid working on the shoulders of the edge.
Trying to remove stock with the 204 is headache inducing ( yes even with the diamonds...).
And after a lot of time using it you develop an acute feel when you are efficiently flush with the very edge to the stone, the sharpie trick is handy to build that sense.
Having said that, keep in mind that i never got a hair whittling edge from the 204 in 13 years or so without stropping, in fact the first HHT edge i got right from the stone was with a lapped 204 medium rod held in hand.

 

[Esav Benyamin]

The Sharpmaker is not a precision sharpening tool but one way to minimize problems is to follow the instructions which say to stroke the blade gently down the rods. The harder the pressure, the further out of line you push the rod.

 

[samuraistuart]

Yeah, your own hand is going to have more angle inconsistency than the few degrees the rods are pushed out. It is not a precision sharpening system. But a very very good system for quick runs.

If I were you I would edit the title of your post. It is inaccurate.

 

[skyhorse]

The Sharpmaker is not a precision sharpening tool but one way to minimize problems is to follow the instructions which say to stroke the blade gently down the rods. The harder the pressure, the further out of line you push the rod.

That is the most likely reason some people get less than desired results from the Sharpmaker. Too much pressure will also prevent the abrasives in the rods to cut.

 

[eKretz]

Yes, I only use my Sharpmaker for quick touch-ups with micro bevels. It excels at this.