The first MetMo Driver that everyone fell in love with was a mild steel prototype that was machined in Geoff's workshop. He's built his workshop up over 40 years, and he'd be proud to tell you that he has more equipment than some manufacturers! With this equipment and expertise we were able to produce the MetMo Driver.
Geoff used a Myford lathe and a milling machine to do pretty much all the machining on the Driver. The mild steel is of course much softer, and much easier to machine, but even still it took a week to get the one prototype made.
At the time we were producing the real ones from aluminium so originally the machines we were using to make the parts could handle that repeatedley with a very low scrap rate.
When we began working in stinaless steel from our backers feedback, the stainless steel was even harder to get right. You may remember the stainless steel barrel that was released as an add-on in the original Kickstarter, and you can see below just a few of the issues we encountered during the machining process.

Milling the pin holes resulted in the alignment being off, and the slot for the barrel pin wasn't parallel. Getting these issues nailed took a lot of work, and even then they still had to go through a rigorous QC process and some required bedding in before they were good to send.
Because of this, we knew that a fully stainless steel Driver just wasn't possible with the tools and machines we had available.
But then...

About four months ago, we started working with a Swiss-type CNC machining centre, and we knew our dream of a stainless steel Driver was in reach. The new CNC lathe gave us the ability to create the intricate detail required for the Driver in the toughest stainless steel. The Swiss-type is designed specifically for this high level of tolerance on hard to machine metals, and the results speak for themselves.

With this we we able to make the barrel repeatedley and also the more detailed bit holder handle, so every stainless steel Driver will have built-in bit storage.

I think this is the tool I've been the most excited about us making!