First, Stephen came up with a series of beautiful wooden handles to replace the early plastic ones on the LONDINIUM espresso machine and a matching set for the HG One grinder. Then, he set to work to design and produce a beautiful acrylic funnel for the portafilter of the LONDINIUM and from there it as a logical step to develop an acrylic cradle / portafilter holder to directly grind into.
The HG One "blind tumbler" is a piece of beauty and a very clever instrument already, but the idea to grind directly into the portafilter was appealing and a good reason to tinker and experiment in the workshop.
Stephen uses a set of extremely strong little Neodymium (NdFeB) Grade 52 magnets to guide the PF holder to the exact ideal spot right under the center of the HG One burrs.
He sent me a complete set but it was up to me to do the meticulous drilling in the bottom plate of the grinder. It proved a little difficult to find a drill of the right size, half an inch, here in Amsterdam where this is about 12.7mm.
I took the grinder to http://www.metaalwinkel.nl and there, Coen helped me by doing all the drilling, first hammering in a center point on the spot I had found using detailed construction diagrams provided by HG One. He then used a small drill, and a slightly bigger one, step by step approaching the size we needed. He measured the hole to make sure he wouldn't drill through the base plate all the way. We want the strong magnet to remain an invisible hand guiding the portafilter.
At home, I poured a little glue into the hole, slid in the magnet and tested the setup.
Perfect! Thanks Stephen and thanks Coen!