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Yes, the formula is confusing at first glance. The formula is valid when the AngleMaster setter is touching the wide primary bevel, shown blue in the sketch below. It was my attempt to explain your issue.   

If the AngleMaster setter is touching the secondary bevel, shown red, than no correction is necessary. It is a standard situation described in the handbook. 

Jan

Jan, if there is already an existing cutting edge on the knife. I think the best thing to do is just regrind the existing bevel.  Now from the existing cutting edge I will be able to know what angle it already have.... then from there I will just chase it to the desired angle.

Because your knife is thick the angle of your blade (primary bevel edge angle) may be some 20° or more. If your desired edge angle is 30° you need to set 30° - 20° = 10° on the AngleMaster. 

In my understanding until now you were ignoring the blade tapper and so unintentionally sharpening an edge angle 30° + 20° = 50° which could resulted in throwing the knife back at the operator when sharpening towards the edge.

Jan

Your formula is very confusing?


I also use the Tormek T7 to sharpen thin kitchen knives ( 2-2.5 mm ). The angle I use 25 degrees.  With that angle from the Angle master it will create a nice cutting edge.  Around 2mm wide on both side.

Now with the thick 3/16 blade. At 30 degrees it will create a  2mm wide cutting edge.  However, it will have an unbalance cutting edge. One side will be  2mm the other will be around 2.5mm .  Now if I do the mods on the jig I think it will fix that problem.


If I will follow your formula and set it to 30-20 = 10 degrees on the Angle master. How big will the cutting edge be 5mm? or even more...

Jan, yes I measure the angle from how it is shown on the book. From my observation using the angle master. If I set the angle at 25 the knife will not throw back at me, but once I go above 30, it has that tendency to happen.  The 30 degree angle will show a nice looking cutting edge ( around 1 to 1.5 mm ). Below 30 will show a much wider cutting edge ( 2-3mm ) which is not appealing when you plan to sell the knife :-(

[Third jig]

Third jig with 1mm ground off the static clamp.
Spacing from the centreline of the handle to the bottom of this jig is 1.25mm + 1mm = 2.25mm
Ideal for 4.5mm knives, but well acceptable for 4-5mm thick as well.

Taking off a 1mm from the static clamp. Does it mean .5mm to be machined off on per side?

Ok, I had found the solution on this post...

http://forum.tormek.com/index.php?topic=2962.msg16395#msg16395

I have just learned on my other post that the knife jig of the tormek can only be precise when holding up to 3mm thick blades. Is this correct? My knives are mostly 4.8 mm ( 3/16 ) thick.  Do I always have to turn the stop of the knife jig to make the correct angle every time I turn over the knife.  Any help is greatly appreciated :-)

Thanks Ken :-) I really like the tormek, It is the most versatile and well built sharpening system in the market today.  However, there are still a lot to be discovered to maximize its use  specially in sharpening knives. 

https://www.youtube.com/watch?v=BKjMilG9LWY

I did the horizontal sharpening today and so far the result was okay. I was able to sharpen the knife at a 30 degree angle and the result was okay. ...It was razor sharp :-)

Is there any disadvantages when sharpening on the horizontal position?

I was wondering that and if you were lifting the handle or tilting the handle.
https://www.youtube.com/watch?v=fYURcwkKGPs

I just lift the handle.

Are you forgetting to halve the angle? For example, if you want a 40° edge angle on a typical knife you'll sharpen each side at a bevel angle of 20°.

Isn't it that you only half the angle on thin knives with a small bevel? My knife is 3/16 thick and the first bevel is wide....I don't divide the angle setting.

I will try it tomorrow and see how it works :-)

I saw this one sharpening on reverse...

https://www.youtube.com/watch?v=BKjMilG9LWY

.
Have you done some experimenting on fitting the jig in the second position and turn the T-7 around so the stone rotates in the opposite direction?

Is it done on this position? How do I measure the angle?

It usually grabs the knife back when it hits the " A " portion of the blade . At the  " B " portion it is fine. This usually happen at 30 degrees up. The higher the degree the most likely it will grab 

I have a tormek T7 that I bought 2 years ago. I used this machine to sharpen long and thin kitchen knives. So far I find the results very good. Recently I started to get in the knife making hobby. For my first initial offering I made two models. A small knife with a 3 inch  Wharncliffe blade and a survival knife with a 5 inch drop point blade.  This two knives are made in D2 steel and has a 3/16 inch thickness. The angle I choose is 30-35 degrees since this two are both sporting knives. 

Now, one problem that I have noticed is at this angle the knife has a high risk of throwing back at the operator. It has happened so many times already that some times it will put a damage on the stone.  When this happen, I fix the wheel with a truing tool.  Is there a way to fix this problem? Am I push the blade to hard on the wheel?