Consistent Angle Differences (Potential Issue)

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1

Wanted to see if what I am seeing with my Wicked Edge is an issue or if it’s just a byproduct of something I am doing incorrectly.

The issue I am having (now that I have sharpened 20+ knives with the WE) is that the anlge of the bevel on one side always seems steeper than the bevel on the other side.

I mount the knife and after sharpening, the bevel on the right hand side always ends up larger than that of the left and it’s been consistently that way for every knife I’ve done. At first I thought maybe it had something to do with the original grind of the factory bevel but now that I am around 20 knives sharepened, I am thinking it’s something else entirely.

It’s almost as if the angle for the right side is one or two degrees steeper than it is for the left. This wouldn’t bother me as much if working with some cheaper knives but now I’ve started to sharpen some of my CRK and ZT knives and I feel like I may be messing up my bevel.

Any suggestions?

2

Hi Jeff, this is quite a common question, so here are some links you might find useful:

[ul]
Full flat ground blades[li]
[/li]
Clamping blades[li]
[/li]
Using an angle cube[li]
[/li]
Linkage play[li][/li]
[/ul]

Success!

3

Thanks for taking the time to respond!

Just a few things related to the posts you mentioned:

  1. Some of the blades (but obviously not all) are FFG. However, for every knife I do pad the top of the vice as mentioned in Clay’s video where he’s working on a FFG Spyderco. I started doing this after the first 6-7 knives.

2)There’s no deformity that I can see with the vice itself that would cause the blade to be canted to one side or the other. Given that it’s consistent on one side that might indicate something slightly off but I can’t see it through visual inspection.

  1. I have also tried using an iPhone app or two to determine angle on the last few that I have sharpened. It does show an angle variance on either side when a knife is mounted but short of changing the angle on the right side to be more than that of the left (i.e. 19 on the left and 20+ on the right) I am not sure how to address the differences. Again, this is consistent regardless of the knife or the type of grind.

  2. I have addressed linkage play by the way I hold the stones as I am working them. I will grip the stones with my thumb, index finger, and middle finger. I place the ring and pinky fingers towards the bottom on the side of the stone facing away from the blade and apply just a little pressure. This keeps the stone from rocking as it transitions upwards. It’s not as comfortable to hold as just relaxing your hands into the slots on the sides of the stones but it’s not too bad.

Again, I appreciate you posting links to those threads and there may be something there that I can improve upon but I think I am using (hopefully correctly) the suggestions other have posted there.

4

Here are a few pics illustrating the left and right side differences…

ZT 0560 Left Side

ZT 0560 Right Side (Notice even the difference in the tip sharpening between left and right)

ZT 0350 Left Side

ZT 0350 Right Side

Spyderco PM2 Left Side

Spyderco PM2 Right Side

5

How much difference was there in the measurements?

6

Usually 1 + degrees. (i.e. 1.x) Sometimes it approached 2 degrees but not often.

7

Hi Jeff,

Thanks for jumping on. Can you please look at the photo below and take the measurement indicated on both sides of your sharpener with the angles on both sides set to the same setting?

Attachments:
8

Will do! I’ll be back in town tomorrow night and will take the measurements then.

Thanks for being so engaged with your product. It’s refreshing!

9

[quote quote=“JeffSimmons” post=3765]Will do! I’ll be back in town tomorrow night and will take the measurements then.

Thanks for being so engaged with your product. It’s refreshing![/quote]

My pleasure - looking forward to your pictures.

10

Hi Clay,

I took the measurements with a caliper with the set screws in on both sides at 20 degrees. When measuring the right side it came out to 1.06 (where .01 = 1/64 of an inch) On the left side the measurement came out to 1.09.

That would certainly be enough to make the right angle at least somewhat steeper than the left but while 3/64 of an inch difference seems like it might be the issue, I am not sure if it’s enough to be contributing to what I am seeing or not.

Thanks!

11

I had the same issue with mine

used a caliper for verifying it

I will not get into how disappointed I had been with the system for the first week of trying to work out why every thing was blunt when I got onto the slicing table

I also noticed different stone kits had different thickness’s that changed the angles a bit

so I had no choice but to re burr for every grit I changed over to

until I made a micro angle adjustment that I use to recalibrate each stone with

much like what you have finally came up with along with your new ball joint design

mods

1st being gluing down the main jaw
( seriously aluminum is no good for screwing things into its just to soft )

2nd adding spring to the angle adjustment screws
( kept coming loose after about 20 pass’s )

3rd making longer thicker rods with ball joints and having protective boot
( to much play in the rods and jig was useless for larger knifes ie. machetes )

4th making new jaws
(same height just not aluminum so they are stronger and thinner allowing lower angles)
/
new base as the angles where not asymmetrical aluminum might have stretched or drilled in wrong spots?

5th finalizing making micro adjustment as the different stones were throwing angle off
( our ball joint system sits on a rack and pinion system that is adjusted by a worm gear )

6th making another knife holder steadying pole with clamp and height adjustment

the original pole was higher then the level of the knife keys and gap was to shallow for any of my knifes to even for their tip to go into

its hard getting dad to build something that you want until you waste a heap of money on something that needs improving … he likes his KISS theory to much

so far with all the modifications we have almost rebuilt the entire jig in fact the only part that is still being used is the angle bar because math hurts my head to much :stuck_out_tongue:

all in all love the WEPS more then my edge pro even tho its been completely remade apart from the stones

12

[quote quote=“ChristopherStaples” post=3801]

mods

1st being gluing down the main jaw
( seriously aluminum is no good for screwing things into its just to soft )

2nd adding spring to the angle adjustment screws
( kept coming loose after about 20 pass’s )

3rd making longer thicker rods with ball joints and having protective boot
( to much play in the rods and jig was useless for larger knifes ie. machetes )

4th making new jaws
(same height just not aluminum so they are stronger and thinner allowing lower angles)
/
new base as the angles where not asymmetrical aluminum might have stretched or drilled in wrong spots?

5th finalizing making micro adjustment as the different stones were throwing angle off
( our ball joint system sits on a rack and pinion system that is adjusted by a worm gear )

6th making another knife holder steadying pole with clamp and height adjustment

the original pole was higher then the level of the knife keys and gap was to shallow for any of my knifes to even for their tip to go into

its hard getting dad to build something that you want until you waste a heap of money on something that needs improving … he likes his KISS theory to much

so far with all the modifications we have almost rebuilt the entire jig in fact the only part that is still being used is the angle bar because math hurts my head to much :stuck_out_tongue:

all in all love the WEPS more then my edge pro even tho its been completely remade apart from the stones[/quote]

Wow, woud love to see some pics if you could post some!

cbw

13

[quote quote=“JeffSimmons” post=3797]Hi Clay,

I took the measurements with a caliper with the set screws in on both sides at 20 degrees. When measuring the right side it came out to 1.06 (where .01 = 1/64 of an inch) On the left side the measurement came out to 1.09.

That would certainly be enough to make the right angle at least somewhat steeper than the left but while 3/64 of an inch difference seems like it might be the issue, I am not sure if it’s enough to be contributing to what I am seeing or not.

Thanks![/quote]

If I measured/calculated right, this should only be about 1/3 deg. difference, not the 1+ deg. difference you said you’re getting.

One other thing you could try, is to mount a knife, measure the angle, then turn the WE around and remount the knife, see if the error “switches sides”, or stays the same. This will help show if the error is in the WE or not. I’d try this with a knife with flat sides, so you’re less likely to introduce a mounting error.

cbw

14

Confirmed your math. I did the trig with measurements that included a knife mounted where the bevel was 4.25 inches from the base of clamps.

Tan = Opp/Adj where the measurements on the left side were 4.252.09 and the measurements on the right side were 4.25/2.06

Left = 2.0334
Right = 2.0631

Calculated inverse tangent to get the missing angle (at the bevel) and got:

Left = 63.82
Right = 64.14

This is about 1/3 of a degree difference. Not sure where the other 2/3 +/- of a degree is coming from. Wherever it is, it’s consistent… :slight_smile:

Maybe I am just consistently doing the wrong thing! :stuck_out_tongue:

15

Interesting, you guys have another player here working on a SC vise.

16

[quote quote=“JeffSimmons” post=3759]Here are a few pics illustrating the left and right side differences…

ZT 0560 Left Side

ZT 0560 Right Side (Notice even the difference in the tip sharpening between left and right)

..[/quote]

well, that is nice math but… can you measure the angles and tell us what they really are on this blade? a goniometer measurement would be best, but you can estimate with an angle cube and the WE rods themselves (no paddles installed), or a careful use of a straight edge, this would be helpful

.. this is perhaps not an angle issue or an issue with the WE, but is a good example of blade asymmetry as a result of sharpening technique. See Ken S excellent vid that discusses this in detail :

The key concept of this video is that one can adjust blade asymmetry simply by adjusting how much you grind on either side of the knife and it is completely unnecessary to change angles when adjusting asymmetry. Stated another way, you can have extreme blade asymmetry while at the same time having exact and identical angles everywhere and on both sides of a blade.

Link to Kens Video

17

OK, this popped into my head driving. So haven’t thought it out too far but…

If its technique, spin the WEPS around and mount the knife from the back, so right is left and left is right and sharpen a knife. YOu know, mounted like normal just the WEPS backwards.

If its your left hand technique or whatever, should show it no?

Like I said, just popped into my head, but then again, my head is firmly up my rear in most cases so take this idea with a grain of salt :slight_smile:

18

Well, Dan did make the point that grinding on one side more that the other can make for a larger bevel even with both sides at the same angle. So you can match bevel widths by grinding for a longer time on the side that is shortest.

Ken