T1 and importance of correct angle

[Kaskar]

Tl:DR If you grind at too narrow of an angle the T1 will not work correctly.


Got a T1 for Christmas and have used every now and then. Good results on some knives. However some knives I have not really gotten the results I was hoping for. Some knives were cheap stuff where I had no hopes of a good result but also on some of my Zwilling knives.

To be fair. Before I got the T1 I have been playing around with wetstones and the factory angle on the knives are long gone due to my experiments. So I googled and found some info saying they could be sharpened at an angle of 10-15 degrees. I wanted them *sharp* so I went with 12,5 degrees. That should do it!

But no. For some of the I had to finish them off on the wetstone to be really satisfied.

So during my vacation I decided to get to the bottom of it. Why aren't they getting sharp!?! Did a clean sweep on a knife at 12,5 and put it under a magnifying glass. I noticed that there was a small, small area at the very edge of the knife. Just micrometers wide. At first I made the angle even more shallow (should be even sharper right?)and noticed that the area got bigger. So I flipped it all around and went up to 17. And all of a sudden it was gone! Gave the knife some time in the machine and soon enough I got a really good burr on the edge.
Turns out if you go to shallow of an angle, the knives edge will surpass the grind stone and not be in contact with it. The knives have pretty thick blades so I guess the geometry gets messed up in the machine. No wonder I was getting a bad results. Worked through the knife on both edges and it passed the paper test with flying colors!

It should be noted that there is still a visible line between the 17 and 10 degree bevel on the knife and it probably needs a good amount of work to repair that mistake.

But it's obvious the idea "a narrower angle should make it even sharper" does not apply on the T1 as it's not even applicable for all knives.

Thanks to people posting here stating the importance of the burred edge. I didn't really feel a burred edge on those shallow angles but I thought maybe it's because I was making it extra sharp. But it's the machine not able to burr the edge.

So for you who have trouble getting a good result on the T1. Make sure you find the right angle and never think that narrower angles will automatically make the knives even sharper.

[Ken S]

Welcome to the forum, Anders.

Have you watched the Tormek online class on the T1? Here is a link:

https://www.youtube.com/live/nqD0cefN0yU?si=tC8_GUFZNH2qrlPr

To eliminate the possibility of confusion, the angle setting scale is for the bevel angle, sometimes stated as the degrees per side. An example of this is a 15° setting on the scale would produce a 30° total angle (15° on each side),

The other point to clarify is that your situation is not unique to the T1. You would also experience this with any round grinding wheel of flat bench stone..

Years ago in the US, the standard angle setting advice for kitchen knives was 20° per side. This was solid advice, maybe too solid. In Europe, the standard setting was 15° per side. We finally caught up with our European bretheren and 15° per side now seems to be standard everywhere. While this may not be "the ideal" for all knives, it is certainly workable. It is what I use.

I suggest you carefully sharpen one knife to 15° per side. Make sure you raise a burr consistently the whole length on both bevels. Be sure to follow Samuel's advice of taking a final light single pass on each opposite side to remove most of the burr before proceeding to the honing wheel.

I especially like Samuel's reply to my comment where he says he hones before each cooking session. I also prefer to dampen the honing wheel.

Keep us posted.

Ken

PS I had never heard "Tl:DR" (too long: didn't read) I think it may apply to me; my wife says my posts are too long.

[Kaskar]

I did watch the videos when I first got it and I thought I got the hang of it. My big mistake was the notion that a sharper angle makes for a sharper knife so when I didn't get a good result I made the angle even more sharp even going below 10.

In fact the best solution is the other way round. Seems contra productive and my guess we who think we know it all and don't think the T1 is working (as I do see quite a lot of posts about it here in the forum), most of us have done the same mistake.

[Ken S]

Stick with the 15°setting on the T1. You will soon be proficient.

Ken

[robkcc]

Just a few tips. Sharpening is just one of two steps to obtain a sharp knife.
You'll know that the sharpening is done when you can feel a burr on the very edge of your knife. Use your fingertips, the nail of your thumb or even a piece of paper. Does the edge "catch"? That is your burr.

Step two is removing that burr. One or two very light finishing passes on the diamond wheel, then over to the honing wheel. The composite wheel will deburr the knife, take your time and don't be shy to give it an extra pass. Check if all the burr has gone. If not, repeat.

With *all* the burr gone, you'll enjoy a sharp knife.

Don't worry to much about angle, take a reasonable setting as Ken suggested.

[Ken S]

Prussian General, Carl von Clausewitz, famously said, "The enemy of a good plan is the dream of a perfect plan". 15°per side may not always be the perfect plan; however, it is a good plan.

Ken

[robkcc]

Who would have thought Carl Philipp Gottfried von Clausewitz's influence would also affect knife sharpening.

When I'm dealing with a "stubborn" knife, I set it aside and threaten it with another saying of the general: "war is the continuation of diplomacy by military means". That usually does the trick. 

[Ken S]

Touché, Rob.   I will add that to my favorite quotes!

Ken

[Tri0de]

Thank You!

[Tri0de]

"Although our intellect always longs for clarity and certainty, our nature often finds uncertainty fascinating."
Carl von Clausewitz

[Ken S]

Good thought!

Ken