Up until now, I’ve only made tyres out of 316 Stainless Steel, which is supposed to be machinable. While small wheels were not too bad, my little Sherline lathe struggled with the 17.5 mm drivers of #622. So, I asked the local Metal Supermarket to bring in some 1″ 12L14 free-machining steel. They probably sell 3/4″, which would be more appropriate for Percy, but, well, I actually didn’t know I would be making for wheels for Percy when I purchased it.
I’m happy to report that compared to the 316, the 12L14 is very easy to turn. Even plunging the form tool into the tyre blank barely stressed the machine at all. Now I will just have to keep the model from getting wet and rusty.