The very basics of cutting rocks
Each solid material is held together by a combination of many different forces and it takes energy to overcome those forces. Energy is measured in Joules ("jools") and rock mass (weight) in kilograms. A kilogram of each material needs certain number of Joules to break it apart.
In general, the harder the material, the more energy one needs to break it up.
But that is not enough. One can deliver certain amount of energy to the rock in millions of tiny taps, or he can deliver the same amount of energy in one split-of-a-second mighty blow. And he has more chances in the second instance.
So the speed or the rate at which the energy is delivered is important.
The rate of energy delivered per unit of time is power. Thus the rate at which rock (or other material) is broken up during cutting or grinding is proportional to the power delivered by the cutting tool.
The more power the machine transfers to the material, the faster it will be broken up.
We've touched upon the next important point: it doesn't matter much how much power the machine has, rather it is important how much of its power it transfers to the rock.
That transfer is done via the cutting tool. If the cutting tool were an ice disc, it would just slip happily along the surface, gradually melt away and very little energy or power would be transferred to the rock. The tool must be such that it doesn't just slip, it engages with the material it cuts.
It can do it by many different ways. It may just run along the surface and heat it by friction so that the material melts away. It may dig into the material and rip it apart. If it is impossible to get between the grains, it may remove material by continuously scratching the surface and removing material in millions of tiny scratches, like it is the case of grinding (in metal grinding it is the combination of this scratching and surface melting). To remove the material efficiently this way, it is obvious one needs speed.
In conclusion it is important to realise that to design a good rock saw, grinder or crusher one needs to first understand what is happening on the microscopic level, how to break the various bonding forces in the material, which one to attack, to understand and design the interaction between the cutting tool and the rock. Only after this comes the design of the machine, which the operator sees.
Understanding these minute details and having decades of experience in building reliable machinery in many fields is the key to the success of Echidna rock tools.