Wskt-ko blade grinding attachment

Bobby3326

Bobby3326

Joined
Mar 16, 2013
Messages
2,239
Does anyone else have or use the blade grinding attachment for the ko work sharp? I just picked it up yesterday and was just now getting a feel for it when I made a confusing discovery. Im using the x4 belt and using sharpie along the edge to get a feel for the machine before using the coarser belts.

Well the knife I'm using has already been sharpened on the regular ko work sharp@ 22.5° per side, now using the blade grinding attachment I adjusted the angle until I removed the Sharpie which ended up being @15° per side.


So now I'm a lil confused at to which one is correct.
 
Correct is in the desire of the owner--if you're talking about angles. Depends on the knife and your preference. Some manufacturers recommend an angle.

I do most of mine at 17 degrees (34 all inclusive).

Mike
 
EyeDog said:
Correct is in the desire of the owner--if you're talking about angles. Depends on the knife and your preference. Some manufacturers recommend an angle.

I do most of mine at 17 degrees (34 all inclusive).

Mike
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I'm not asking what the correct angle to sharpen at is I know what angle I want. However I have the work sharp Ken onion edition and the blade grinding attachment for it. The knife was sharpened on the normal work sharp at 22.5°, but when using the blade grinding attachment in order to match it I have to set it at 15°. So one of them isn't sharpening at the correct angle.

I'm trying to figure out which one is off, and if anyone else with this attachment has noticed this. so I can adjust accordingly to get the right angle.
 
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I've noticed the same difference between my WSKO and blade grinding attachment. You must set the angle lower than what you actually want on the grinding attachment. Sharpening using the 20* setting will give you around a 25* angle, and the 15* setting will give you around 20*. I'm thinking this may be tunable by tweaking the belt tension and the distance between the two pulleys at the top of the unit (both adjustments appear easy to make). I've only had mine for a couple weeks, and I haven't had the time to really mess around with it and make these adjustments.
 
Sorry...misunderstood what you meant. What G. Scott H. says is the problem. Belt tension can be problematic.

Mike
 
G. Scott H. said:
I've noticed the same difference between my WSKO and blade grinding attachment. You must set the angle lower than what you actually want on the grinding attachment. Sharpening using the 20* setting will give you around a 25* angle, and the 15* setting will give you around 20*. I'm thinking this may be tunable by tweaking the belt tension and the distance between the two pulleys at the top of the unit (both adjustments appear easy to make). I've only had mine for a couple weeks, and I haven't had the time to really mess around with it and make these adjustments.
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Ok that's the info I was looking for, I wanted to try narrowing down whether one or the other is defective by if others also have experienced this.
 
I hope I'll get to mess around with the tension on mine this weekend. Other than the initially wonky angle discrepancies, the grinding attachment is giving me the best edges of any device I've used thus far. :thumbup:
 
G. Scott H. said:
I hope I'll get to mess around with the tension on mine this weekend. Other than the initially wonky angle discrepancies, the grinding attachment is giving me the best edges of any device I've used thus far. [emoji106]
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I haven't used much since I just got it yesterday, but once I used the Sharpie and found the angle was off I got great results on that knife. I was hoping it was powerful enough to do some real grinding as I want to fully convex a few knives, and thin out the primary grind on some, but after trying a full convex on a cheapo Gerber I don't think I'll even try on my good ones.
 
I bought mine strictly for sharpening and for very minor grinding work, like smoothing and rounding the spines on Opinels I mod, etc. I don't have plans to attempt any heavy grinding, as I can see where it might put quite a strain on that little motor. A nice full size belt grinder would be the ticket for that sort of work (and unfortunately rather expensive :().
 
G. Scott H. said:
I bought mine strictly for sharpening and for very minor grinding work, like smoothing and rounding the spines on Opinels I mod, etc. I don't have plans to attempt any heavy grinding, as I can see where it might put quite a strain on that little motor. A nice full size belt grinder would be the ticket for that sort of work (and unfortunately rather expensive :().
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harbor freight 1x30 start at $50... May have to get one.
 
There are likely two factors at play in the angle differences you are seeing:

1. Every blade has some sort of thickness to it's grind, which equates to an included angle. For most knives, the total included angle is something like 8 degrees (4 degrees per side). Thinner grinds have a smaller number while thicker grinds might have 10 or 12 degrees included (a very thick grind). When using an angle guide, you're going to get the guide angle number plus the knife's native angle. For example, if the knife's native angle is 4 degrees per side and you use a 15 degree guide, you're going to get 19 degrees per side.

2. The BGA uses an angle reference plate to help you hold the blade horizontal to the floor. I haven't used one, but I think you're going to suffer from #1 above, as the side of the blade isn't parallel to to the center line of the blade. In fact, if you're trying to visually hold it fully horizontal, in the same plane as the center line of the blade, you'll need to use a different visual reference. The side of the blade won't work. Instead, something like the flat part near the choil on most blades in actually in the same plane as the center line.

In the end, all that really matters is how your blade cuts and how it looks. If it meets your standards on both, the actual numerical angle isn't very important, in my opinion.

Brian.
 
bgentry said:
There are likely two factors at play in the angle differences you are seeing:

1. Every blade has some sort of thickness to it's grind, which equates to an included angle. For most knives, the total included angle is something like 8 degrees (4 degrees per side). Thinner grinds have a smaller number while thicker grinds might have 10 or 12 degrees included (a very thick grind). When using an angle guide, you're going to get the guide angle number plus the knife's native angle. For example, if the knife's native angle is 4 degrees per side and you use a 15 degree guide, you're going to get 19 degrees per side.

2. The BGA uses an angle reference plate to help you hold the blade horizontal to the floor. I haven't used one, but I think you're going to suffer from #1 above, as the side of the blade isn't parallel to to the center line of the blade. In fact, if you're trying to visually hold it fully horizontal, in the same plane as the center line of the blade, you'll need to use a different visual reference. The side of the blade won't work. Instead, something like the flat part near the choil on most blades in actually in the same plane as the center line.

In the end, all that really matters is how your blade cuts and how it looks. If it meets your standards on both, the actual numerical angle isn't very important, in my opinion.

Brian.
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Ok that makes since..on the regular work sharp the spine rests against the guide as it's pulled thru...So on the bga the spine is merely a reference point to hold the knife level and so it's hitting the belt level which would make the bga grind at 15° when the regular version was set at 20°. The thickness of the spine makes the knife sharpen at steeper angle than selected on the regular version..

And yes I agree as long as it's sharp and it works it's all that matters...I was merely concerned about a defective unit at first, but what you said makes sense.


It definitely gets a knife wicked sharp, the regular wskt-ko sharpener worked great, but never got em hair whittling sharp before. This set up does thou.

x6paSKP.jpg
 
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As for the angle discrepancy on the BGA, one other thing to check: your unit may have come with the notches of the angle guide misaligned with the notches of the part above it where they interlock. This happened to me. I removed the angle guide and refitted it into the notches above so that the angle on the guide jived with the angle on the belt section at the top as per an angle cube.

Andrew
 
Aside from the angle discrepancy the bga is a great addition to an already great product. I thought after discovering that it wasn't capable if any real grinding tasks I was gonna return it, but after using it for sharpening have decided to keep it. This thing puts a great edge on and is actually pretty easy, and getting a nice sharp tip is simple as well.

I think I'm definitely preferring this over the regular wskt-ko.
 
bigretic said:
Not trying to hijack but has anyone tried linen belts loaded with CBN on the BGA?
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I have. I use a 16/4/1 micron CBN progression on linen. The results are great on high carbide steels. I found that after setting a bevel and apexing the edge, dropping the angle a degree or two when using the linen belts results in a noticeable increase in sharpness. For non-carbide steels I really like the trizact belts, finished on the leather belt with boron carbide.
 
Indignation said:
I have. I use a 16/4/1 micron CBN progression on linen. The results are great on high carbide steels. I found that after setting a bevel and apexing the edge, dropping the angle a degree or two when using the linen belts results in a noticeable increase in sharpness. For non-carbide steels I really like the trizact belts, finished on the leather belt with boron carbide.
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Where are you getting these belts for the wskt bga?
 
Indignation said:
http://www.woodworkingshop.com/
Just call them and they will make any size linen belts. There is a small custom order fee, so it was worth it for me to order quite a few.

ken Schwartz sells them individually, but you will pay more per belt.

On a side note, diamond based compounds do not work well with these, or any powered system.
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Awesome thanks,

The blade grinding attachment definitely produces a much sharper edge than that of the wskt-ko. While the regular will get a knife sharp it never got my knives hair whittling sharp. With this attachment my knives are sharper than ever, and easily whittle hair. One knife so far is so sharp it can't whittle hair bc it just cuts it in half.

Very impressed with my results from this thing

gAxIMGA.jpg
 
The best thing about the blade grinding attachment is the control you gain over the regular work sharp.

With the regular work sharp you always end up with the wide convex bevel, which is good for some knives. However ones with a micro bevel like the tops bob are reprofiled using the regular work sharp, but with the attachment you can touch up the micro bevel easily and not change the bevel profile.

Not to mention the ridiculously sharp edge.

j9lPmhi.jpg
 
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