First I would like to quote words from this article (I recommend reading it all)
https://scienceofsharp.com/2016/12/21/a ... t-vs-grit/
In the study and literature on the topic of grinding and wear (tribology) the terms “sliding, ploughing and cutting” are commonly used. There is a critical pressure required for an abrasive to cut into the workpiece, otherwise it will simply slide without removing metal. Efficient grinding occurs when the particles are cutting. If the exposed abrasive becomes worn, the contact area increases and the effective pressure decreases (for a given applied force) and we will move from cutting to sliding.
dlum1 wrote: ↑Thu Oct 13, 2022 2:45 pm
Something doesn't sound right here. You're forgetting pressure. With it, a round object can definitely cut. Press a metal ball bearing against a sheet of drywall and drag it. It can definitely leave a gouge mark. With such a small surface area near the edge of a blade, a light force can result in some significant pressure.
I tried to do this and I did not succeed. A small metal ball simply slows down from my hands when I begin to move it along the sheet.
Newton's third law - To every action there is always opposed an equal reaction
In your example, you missed that the ball is not fixed motionless. Your example would work if the ball had a comfortable handle to hold, so that you could create a pressure on the ball, to move along the sheet.
The grain of abrasive in the stone is not fixed motionless, it is kept due to "glue". Glue can be strong(norton india) and weak(king stone). There will be some kind of pressure on the abrasive when the abrasive will break out of the stone. The more round abrasive (dumb), the more it must be pressed on the stone, so that he again begins to cut the metal. This pressure can be so large that the whole stone will destroy, or it will not work to do anything.
Josh Crutchley wrote: ↑Thu Oct 13, 2022 3:36 pm
Bonded stones are not expensive when compared to quality diamond plates. For the size of stone I use DMT plates are 10usd cheaper. So for 10 bucks more I get a stone that lasts longer. Atoma plates are almost twice as much.
Every diamond plate I've used has lost effectiveness after a few months. Once that happens there's no way to make it cut like new. Bonded stones go through the same process but you can dress them to make them cut like new. You can dress a bonded stone multiple times which increases their value.
I would not want to greatly discuss the issue of price, otherwise I will have to consider a large assortment.The price depends on the concentration of an abrasive, for example, Venev diamonds (25% vs 100%). Some can be just expensive, like Naniwa Diamond.
When you are talking about reusable, it is difficult.
Problems in details and trifles.
For example, the density of abrasive per unit area is important. For example, we have 1 cubic millimeter of diamonds, we can pour them onto the plate, or can knead with a filler and get 1 millimeter of diamonds with a filler. Is it correct to compare and say that one is better than the other and more durable?
Diamond plates lose their aggression after small use. But we can say that this is their nature and a feature. They become a little aggressive, but they still work very well. Supported that they go to the operating mode.
You need a stone for some kind of work, and not for it to be like new.
Ultimately, the speed of the stone is important to us. The volume of the metal that is removed in one movement at a given pressure on the square. I'm talking about the experiment, the link to which I gave at the beginning of my message.
If we had these values, we could easily compare abrasives, but we don’t have them.
Ramonade wrote:
Resin bonded diamond stones and electroplated stones do not only differ in lifespan. As Shawn said, since the diamond are IN the bonding medium, they are not showing all the way. The grit stays the same, they cut as efficiently as electroplated stones for the same grit.
However, there's a difference in how deep the electroplated diamonds go in the steel, and this is the case for every grit. When your using 220 grit it's not that important, but at very high grits and given the choice, you'd prefer a resin bonded diamond stone for a cleaner edge (= sharper)
This is a very very controversial statement.
I drew a small picture, this is a type of abrasive stone, depending on the depth of immersion of an abrasive into the matrix.
For comparison, I suggested that the density on the surface of the abrasive is the same in all stones
I do not know what you mean by the word - effectiveness. But the following logic
(The grit stays the same, cut as efficiently same, difference in how deep), the best stone will be the one whose abrasive will be deepened to maximum depth (Perhaps even the one from which the abrasive will not stick out?
). Since the effectiveness does not depend on the depth of the adjustment. And the scratches from abrasive will be less, the more abrasive is immersed in the matrix.
Do not you think that what is wrong here?
If I misunderstood you, please draw you as you imagine these two cases.
's in 10 different steels
