Messages

You're on the right track, Herman. Unless the serrated blade is hacked up, focus on the opposite blade only.

If you've got a good, flat, very fine honing stone, Lap the mating surfaces a bit after you grind the bevel of the one blade.

If the KitchenAids are like most kitchen scissors, it is probably very easy to take them apart, which makes the whole process easier.

Ron,

Everything is compatible, but...you may not have as much of a problem as you think.

Your most likely problem is simply a stone that has worn unevenly. Get the diamond truing tool and true the stone before you spend for a new shaft and grindstone.

Check that the main shaft plastic bushings are in place and not overly worn. The shaft should be smooth where it goes through the bushings. If you find it is corroded and the bushings are worn, then you will need to replace the shaft.

Jimmy,

A concavity usually indicates that you are not grinding enough at the very point of the tool.

To me, all well-behaved, cherished equipment is feminine. Cars, tools, etc.

Stuff I struggle with becomes "it". 

Kenny,

The comments you are referring to are most likely directed at the previous model of the chisel jig. The newer model references from the flat side of the tool, thus greatly reducing the influence of clamping pressure.

That said, it's a good idea to visually inspect the clamping bar and the clamping base and see if they are parallel with each other.

But, it always comes back to monitoring and adjusting.

[set the tool up as carefully as possible....but then grind to square by checking to a try square and adjusting where you grind.]

Kenny,

You're uncovering all the reasons that it is so often repeated here that a square grind is not guaranteed without careful attention by the operator. The issues you raised, jig alignment and Universal Support alignment, combine with inaccuracies in the tool dimensions, inconsistencies in both the stone and the tool, inconsistencies in pressure from dominant hand to the other, and several other little twinks one way or the other to make it critical that you set the tool up as carefully as possible....but then grind to square by checking to a try square and adjusting where you grind.

Alignment of the tool in the jig is only half the job. It is also critical that you keep your pressure equal on both sides of the blade and monitor your work as you go. Keep a small try square close at hand and check the tool frequently. If you find it drifting away from perpendicular, move the short side off the grindstone, focusing the cutting on the long side. Using this method, you can also introduce a crown to the iron, if desired.

Herman,

He's talking about the micro-adjuster on the knife jigs.

The lock was troublesome, as people over-torqued the knob and stripped the threads.

It was replaced by an o-ring between the head and the shaft which limits the movement of the head once it is adjusted. The small bit of movement you might experience in use will not affect the grinding angle in any measurable way.

Doubt that it is the stone getting smaller that caused the change, it's the tool getting shorter that caused the change. Think about it...pivoting on the Universal Support as it does, if you keep grinding, eventually you'll get to a square edge. On anything I'm doing where the angle is actually critical, I always reset the angle once I get the lion's share of the grinding done.

And the angle is measured to the chord between the two points, generally speaking.

To my mind, you're right. Theoretically weaker, but practically immeasurable when the foundation of the argument is a 10" wheel...except on very thick tools like mortising chisels and the like.

I take it from your last sentence you don't want to call him a dunderhead and move on. 

Funny, Ken...when a related subject came up on another forum, I used exactly the same metaphor.

Rob,

It's a complicated dance between the thickness of the tool and the diameter of the grindstone.

In the example you've just mentioned...a plane iron...on the Tormek 250mm wheel you would need some pretty sophisticated measuring equipment to measure the "hollow" cut in the bevel. I'm not enough of a mathematician to calculate it, but I would wager if you either measured or calculated, the depth of hollow on a standard plane iron would be significantly less than .001". I'm not sure how much "weaker" that is.

While this observation is expected when using the SG-250...
Even with the SJ-250 I am getting the somewhat wavy patterns on the sharpened blade which is a factor of my lack of skill using the Tormek to sharpen blade steel..

If you're changing the profile of a knife with the SJ-250, you're a much more patient man than I am. It takes me forever to remove any measurable amount of steel with the SJ-250. How much time are you spending on the knife with the SJ-250 to create a wavy edge?

Courierdog,

The direction of this thread leads me to believe that you are working with the grindstone cutting too aggressively. When working on fine cutlery that only needs a bit of touch-up, it is absolutely critical to get the grindstone as smooth as possible with the SP-650 Stone Grader. The grindstone should feel like wet glass when it is running. You shouldn't be able to feel any "grit" in the surface.

If the surface is properly graded, the grindstone cannot cut fast enough to alter the profile of the knife.

Herman's tool rest is one solution. Another is to simply do it freehand.

It's hard to tell, but I would blame those nicks on impact. I have Global knives, too, and find them to be excellent steel that holds an edge well, but the steel and the hardening process don't take well to whacking. Right tool for the job, and all that.

BTW, anyone notice that we have new categories? Knife sharpening and drill bit sharpening have been given their own space.