Tc, I just checked, and the 800-1k stones on both paddles are seated. It looks like the assembler put the stones in the pocket, then pushed each stone to one end of the pocket or the other, stone-end flush with pocket-edge, but the stones are definitely in there.
How would I check the angle of each stone? Put the paddles in the 90 of a straight-edge/square, zero cube on straight-edge, then cube the paddle?
I’ll go see if I can’t track down a square.
Drew when you track down the square, you can use the square to measure the distance to the knife edge form side to side, with the square sitting flat on the base and slid flat up against the vice side, to see if the knife is leaning to one side.
You probably think my detailed questions in my posts above are a P.I.A. to read and figure out what I’m asking you. If you’d just take the time and effort to indulge me, the answers will help us diagnose your issue. You’ve eliminated a miss-seated mounted stone. Let’s look for another issue.
I knew you’d jump on that. Yes, as soon as I track down the square, I’ll test for straight or list.
We’ve got everything packed in totes in storage. I’m going up to check the manifest.
Marc, I just cubed the flat of the blade. It shows ~.55° off center.
Tell me your thoughts on this.
Found a small 90°.
Base bottom, degree bar, and vise bottom as contact points. Zeroed cube on base and vertical flat of square. Set paddle to measure vertical. Right paddle first, then left. Bottom first, then top. 800 and 1k sides against square. Holding paddles against the square-flat with pressure on bottom.
It’s a poorly controlled experiment, but best I have at the moment.
Right paddle:
Left paddle:
I know that testing 50/80 variance is like testing a hand grenade for accuracy, but, starting from the lowest to highest:
50/80, paddle 1
50/80 paddle 2
100/200, paddle 1
100/200, paddle 2
… it won’t let me post the last orange bottom reading picture. It reads zero, on the money.
Marc, looking dead on the point of the knife, the spine is clamped slightly left of center. It’s sitting more on top of the left vise-pin.
Thanks for the effort, Drew. As you said it’s a hard and crude method to employ when dealing with 0.25º<>0.50º which are very tiny differences and especially using the AccuRemote digital cube which isn’t always the quickest meter to settle in and lock, and juggling everything like you did. Allowing for molding imperfections in the plastic handles and the difficulty using this method I don’t see anything that is really so far off that you can’t still get good results with attention to detail and good technique. You may have to play with your finger position and pressure or flip the stones end for end or side for side to find the orientation that gives you the best uniformity.
I still think the offset knife may be the biggest contributor. I’d like to see you measure the distance the clamped knife edge is from a vertical. Done consistently from side to side. Measuring the flat side of a relatively narrow nonuniform rusted file knife isn’t really telling. IMO.
If the knife is off center that explains the different is the bevel heights seen with the marker when both are set at 15º. It won’t give you uneven bevels. Un even bevels are when a centered knife is sharpened with two different angles for each side.
Your 15º angle is contacting the knife at two different height positions on the bevel. If you removed enough steel eventually that the bevel finally apexed the edge then you would see uneven bevels.
I’m just not convinced. Regardless of how the knife is positioned in the vice, if it’s locked in tight and ground fresh, with no movement in it, that angle of bevel should contact the stones the same, whatever grit I use.
Everything is consistent, that I can tell, besides the stones.
Are you saying that this system will only work putting consistently angled bevels on steel with a knife clamped at 0.00 vertical from base?
I did remove steel to apex, each grit. I don’t mind uneven bevels, as long as the entirety is mirror polished and able to shave neck hair.
Let’s say I did take the knife out, straighten it up 0.00, (I’m not sure what I can do for the left-placed LAA, that may just be the way it is), regrind at 100 grit to apex, then change to 200, then 400, etc. Are you betting that that would give me flat, 15° contact between these different stones and fix the problem?
Here’s the last experiment I’m doing today to highlight the problem:
100 grit, ground fresh bevel flat, apex to back of bevel, bur raised on both sides. Clockwork, and all is well. My reasoning suggests, strongly, that if the 100 grit can reach all parts of the bevel flat, regardless of how the knife is, then twisting the paddles from 100 to 200 on the rod, cubing to 15°, the 200 grit should mimic the contact of the 100s. It should be a carbon copy of the courser grit.
Fingers crossed I can post these pictures.
In the photos you posted, your remaining marker on the bevels indicates your not reaching the apex always. That picture clearly illustrates the clamping lean you see.
The way it is now you’re not sure it is repeatable. If you remove the knife, the LAA and the material between the knife and jaws. The next time it may not come together the same way. A zero reference, vertical knife, is the standard starting position for predictable repeated results. For known, consistent and predictable, blade leans due to a clamping offset, with an angle measurement of the lean and mathematical calculation you can yield a correction factor to adjust your individual side guide rods settings to even out you results. Divide the lean angle amount by two. Add the 1/2 it to the right side angle setting and subtract the 1/2 from the left side setting.
200 grit, 15°, marker to illustrate
That dog won’t hunt.
So far so good! Are these last pictures 100 grit?
Question: did you hold the stone(s), each and every one, flat against the square and inspect for flatness or dishing?