help with angles

[Tilling_guy]

I just got my Tormek T8 last night and I was trying it out on a few cheap knives but I am a bit confused on the anglemaster tool.  I was sharpening a couple of pocket knives.  I understand that the ideal angle for a knife is around 20 to 25 degrees.  Is that angle from the centerline of the knife to the edge or from edge to edge?  For example if it was a 20 degree angle would it be 20 from one edge to the center and then another 20 degrees from the center to the other edge for a total of 40 degrees?  Or is 20 degrees the total angle (10 degrees each side of center?)

Then on the anglemaster tool there are two sets of numbers.  Which number do I set it to if I want a 20 degree angle on the knife?  (Do I use the bottom line 20 or the top line 20)  Or do I need to do set it to 10? (10 +10 on each side = 20)

I know these may be stupid questions but I am just having a hard time understanding the angles in my head.

Thanks

[cbwx34]

I just got my Tormek T8 last night and I was trying it out on a few cheap knives but I am a bit confused on the anglemaster tool.  I was sharpening a couple of pocket knives.  I understand that the ideal angle for a knife is around 20 to 25 degrees.  Is that angle from the centerline of the knife to the edge or from edge to edge?  For example if it was a 20 degree angle would it be 20 from one edge to the center and then another 20 degrees from the center to the other edge for a total of 40 degrees?  Or is 20 degrees the total angle (10 degrees each side of center?)

Then on the anglemaster tool there are two sets of numbers.  Which number do I set it to if I want a 20 degree angle on the knife?  (Do I use the bottom line 20 or the top line 20)  Or do I need to do set it to 10? (10 +10 on each side = 20)

I know these may be stupid questions but I am just having a hard time understanding the angles in my head.

Thanks

Not dumb questions at all.

I'll answer the easy one first.  Use the bottom row of numbers.  The top row is for a different jig (the MB-100) that is used on the side of a diamond wheel.

Angles are typically referred to as the angle per side (degrees per side=dps).  So, when you say the "ideal angle is 20-25 degrees, that is per side... so centerline to edge.

Since, in most cases, you can't set the Anglemaster on the tiny bevel of a knife... you set it on the side of the blade just above the bevel.  This also measures centerline to edge... so you would set it at 20°... if the side of the knife were flat.  Unfortunately, most are not, and you have to adjust for the taper of the blade from spine to edge.  You can either measure this taper with some other method, substitute a "target" (Ken will be along to explain that), or take a guess at what it should be, and adjust accordingly. (you add the taper to the desired angle).  I demo'd this here...  https://forum.tormek.com/index.php?topic=3573.0

Which brings me to what some are already guessing I'm going to say.  Forget the Anglemaster for knives.  Check out the link in my signauture.  It uses an app to easily set the angle (per side), and you don't have to adjust for the knife spine-to-edge taper.  (You will need a way of taking some measurments... a caliper works nicely, or the tool you'll find referenced in the app).

But if you want to use the Anglemaster, since it's what you have, you'll set the angle for the degrees per side (20 in your example, using the bottom row of numbers), set it on the blade just above the cutting edge bevel, and make sure you adjust for the spine to edge taper.

The Tormek video demo's this (starting at 1:22), although they don't adjust for blade taper.

https://youtu.be/zFmGfDULpiQ?t=82

[RickKrung]

Welcome to the forum. 

...snip...I understand that the ideal angle for a knife is around 20 to 25 degrees.  ...snip...

Eliminate that notion from your head and practice.  There is no single optimal or ideal angle for any tool.  For knives in particular, it depends on its design and waht it is going to be used for.  I am not the one to expound on that. 

Rick

[John_B]

As Rick stated you want to sharpen your knives with their intended use in mind.

I have a number of knives that I use outside of the kitchen. For everyday carry I have a few assisted opening knives; none of them are exotic or expensive. I sharpen them at 20° per side so that they can withstand the rigors of use. For my survival knife that I carry in my backpack I sharpen it at 25° so there is more supportive steel behind the edge. For fishing I carry a Finnish filet knife that is sharpened at 12° per side. It slides through the fish to give me perfect filets in seconds. For reference the lower the Degrees per side the more inclined the blade is to chip all else being equal.

If you are cutting a lot of cardboard boxes be prepared to touch up the edge quite often. Cardboard is very abrasive and will dull the edge.

I rarely use the Anglemaster; I prefer the software program which I find easier to use.

[Hogdog6]

Cbsx34 advise on using his software will make you very happy. As he stated you need a measuring device but the investment will be well worth it.

[chino]

I just purchased the tool in this thread. I think it's going to help using the angle program in Cbwx34's signature line.

I've been marking the blade with a sharpie since getting my Tormek. Hope this tool helps in USB adjustment.

The Tormek tool (for me) is a little vague in precision.