So I asked a few months ago about what this kinematics would be classed as and David helpfully pointed out it was just a polar but moving the arm and not the bed.
As I've been forced to take 3 weeks holiday by work due to the current Pandemic, so I thought I'd give it a go making one! Reusing all the hardware off my old printer, I have put this together...
31*32cm build area but in theory with a bigger bed and enclosure could print a 50cm radius semicircle with very little changes to the mechanics.
It's surprisingly stiff and has a ~30:1 ratio on the swingarm stepper so hopefully enough torque and resolution. If this works out I'll replace the 2020 of the swingarm with 20mm carbon tube so reduce the inertia and get some aluminium plate laser cut to replace the existing mechanism as that is the main source of flex.
Now I've just taken a backup of my old settings and just about to dive into the firmware setup, I'll report back with how it goes!