sharpmaker stones angle defect?

J

jacobi

Joined
Feb 9, 2013
Messages
46
Hey All,
Just bought a sharpmaker, popped the stones in on the 40 degree side, got a knife out, and immediately noticed the two stones looked like they were at different angles compared to the knife i was holding perpendicular to the table. I'm pretty new to sharpening, so I thought maybe i wasn't holding it straight up and down consistently, so I got out a t-bevel and there is a 1/8" to 3/16" or so difference between the stones when comparing with the t-bevel. I tried the 30 degree with the t-bevel and it doesnt have this issue, so it seems that the tool i'm using is good enough to see that its out.

Anybody else have this issue? i'm a newb, but this seems like a big difference - or is it small enough to not make a difference sharpning?

Thanks.
 
If you are saying the horizontal distance between the knife spine and the stone is different on each side by as much as 3/16", I'd send it back. Just out of curiosity have you made this same measurement for the 30° side rods?
 
I mean that when I set the t-bevel to one stone, and then move it to the other, one stone is out 3/16" at the top compared to the other - along its entire length. I did the 30° side and they are the not out.
 
The Sharpmaker and other V-crock style sharpeners aren't precision instruments. They're just a tool designed to make 'freehand' sharpening a little more intuitively easy, by orienting the sharpening rods to a 'natural' cutting/slicing motion most-often used with a knife. Freehand sharpening isn't precise either. Most knives, if checked for actual measured angles on both sides, would very likely show at least a couple or three degrees of asymmetry between sides, and it will never matter in the real world. A crisp apex and decently thin geometry behind the edge is what makes a knife cut well, and imperfect symmetry between the two sides of an edge will likely never be noticed in normal usage.

I wouldn't worry about the apparent mismatch between sides; most who use the SM and similar V-crock tools will introduce as much or more error on their own, as it's impossible to maintain the exact same angle by hand on each and every pass of the dozens, hundreds or thousands of passes taken in resharpening a blade. If it were a fixed/clamped/guided sharpening system designed and built (and priced) to be a true 'precision' sharpener, by removing the human error aspect entirely, there might be cause for concern. But not for a tool like the Sharpmaker, which really isn't designed for that.

In a quick & informal check of my own Sharpmaker, with the rods in the 40° slots, it shows ~3/8" of play (lateral movement) at the upper end on one side and about ~1/4" of play on the other side, when pressing inwards toward the center on each rod's upper end. With that much 'slop' in the slots holding the rods, I wouldn't really expect both rods to rest at exactly the same angle; but it's never gotten in the way of putting a crisp edge on my knives.

In checking the inclusive angles on each setting, using a pivoting protractor set flush to the inside flats of the rods, I'm measuring 41° inclusive on the '40' side (accurate within 2.5%), and 31° inclusive on the '30' side (within 3.3%), with the rods 'at rest' in the slots. That's not bad for a cast/molded plastic base, especially considering the 'slop' in the slots holding the rods.


David
 
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it seems you are not alone :), it happens , it can be a bit frustrating but there are tips to deal with it , and spyderco will replace the rods
similar issue Sharpmaker rod play - Spyderco Forums
pics of warped/bent/crooked/notflat/out-of-flat sharpmaker stones/rods/sticks Having Second Thoughts about the Sharpmaker - Spyderco Forums
video of warped/bent/crooked/notflat/out-of-flat sharpmaker stones/rods/sticks Possible reason some people get inconsistent results with the Sharpmaker - Spyderco Forums
warp Warping of Sharpmaker Rods
warp Disappointed with Sharpmaker 204
warp Sharpmaker QC
warp Sharpmaker is flawed from manufacturer
spyderco will replace them Sharpmaker disappoints - Page 2
 
that makes sense thanks - I still don't like the fact that I can see the difference in angle between the two sides but i'll give it a shot
 
I agree with David (Obsessed With Edges)-- I don't think it will matter. It's not a precision sharpening tool. I have never bothered to check mine.
 
Have you made sure you've set the rods as securely as you can in the slots? I know even when I have the rods in completely, I can wiggle the rods. The tolerance on the hole in the base to make it big enough for the rods to stick in, the tolerance on the rods' diameters to make them small enough to stick in the base, and the tolerance on the angle in the base can all add up to a lot of wiggle room and deviation.
 
The thing is, that movement of the rods in the plastic base is irrelevant because when you are using the rods you press them outward into a stable and constant position. But when the edges are different from one another you are going to get a different bevel on each side of the blade. I don't know if that is important or not, but I wouldn't put up with it anyway. Spyderco has had some quality control issues in the recent past and they need to be getting back all these subpar units to show them that they need to get their act together.
 
For clarification, it would be helpful if a pic were posted of the OP's Sharpmaker setup, perhaps utilizing the T-bevel to illustrate how it's being used for comparison. The described issue in text only seems a bit vague to me, as to what's going on. I'm sort of assuming it's issues similar to what I described with my setup (movement & slop/play in the base's hold of the rods). But if there is some freakishly new issue at play with this set, a pic might help clear that up.


David
 
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