Cracking almonds with a hammer is better than a hand nutcracker but nothing like as good as a partidora.
In the ferreteria (hardware shop) in Ancho de Capuchinos in Granada you can buy partidoras.
The price is about 40 euros.
Apparently they are made by an old man up the the Alpujarras in a small workshop.
The partidora consists of a handle which imparts a very large force onto a metal plate.
Almost no effort is required even with the hardest nuts, even a child can do it.
Once you have worked up a rhythm feeding the nutcracker with the left hand and pulling the handle with the right the cracking speed is very fast.
It is a good idea to have one person cracking and another person picking out the nuts and putting them into a container.
I wish it were possible to get a small electric nutcracker. I have spent hours making google searches using terms such as Almond huller, Almond cracker, nut sheller but with no success. The cheapest machines cost over 5000 euros and are for industrial production.
There are also lots of free patents for nutcrackers on sites like this one
https://freepatentsonline.com/But it would be necessary to have a big workshop to make one.
There would be a lot of demand for a domestic electric nutcracker for less than 500 euros espaecially in spain.
Someone should make one!!!