Back in 2005 we designed and began manufacture of the M3 espresso grinder.
In 2005 the coffee world was considerably different than at present. All commercial grinders at that time were of a then conventional type. Hopper on top, start up and grind until the signal from the doser said it was full. Sweep grounds out of the doser with a side mounted lever.
It was a time when most people didn't think the grinder made much difference -- if any. We had some experience that made us think otherwise.
The new grinder was expensive to build - and the market for such a grinder was uncertain - therefore it required careful balancing of precision and cost. As time went on, this balance shifted, since instead of being a crazy notion, the M3 was becoming recognized as a very fine product.
This new grinder of ours had quite a number of brand new features, some or all of them patentable. We believe these were the first applications of the following, but perhaps others can show that they weren't.
Here are some of the unique things that originated with the Versalab M3 grinder:
The entire architecture was an innovation that was derived from the requirements of the goal. No retained grounds, no partly ground beans sitting in the burrs, no heating the beans/grounds.
First, the burr shaft and motor arrangement. In order to be the first grinder that had a straight through grind - beans poured into the top and grounds coming out the bottom - there had to be a design to keep the motor from being in the way. The belt drive solution not only accomplishes this but also keeps the heat of the motor away from the beans and burrs. The shaft and bearing design was critical since the burrs were far away from the bearing support. Using a preloaded back-to-back pair of ball bearings provided enough rigidity.
We chose a DC motor - not a popular choice with other machines - but because it provided more torque than other motor possibilities.
Next the unique top funnel with infinite grind adjustment. We needed a way to get the beans into the burrs!
Once the beans are ground and exit the burrs, the machine needs a bottom funnel to collect them into a portafilter, since the burrs are bigger than most portafilters. In order to clear the funnel and minimize retained grounds, we created a moving wiper that rotates with the shaft, and a fixed wiper to clear the side of the bottom flat burr.
Over the years other innovations were added.
The portafilter holder with two spring loaded plastic levers to hold the portafilter snugly against the bottom funnel. The rubber gasket so the portafilter would not heat the bottom funnel and would also retain its own heat.
And then the dosing hoppers. These are similar to powder measures as used in firearm ammunition reloading. The demands of keeping partly ground coffee from sitting in the burrs between grindings required a remote hopper and delivery system that could measure the desired shot.
I think that covers a lot of the innovative thinking that has been fundamental to the M3 grinder for these many years.