I've been considering building a compact little muller for kicks. A friend dropped off the 450mm dia x 12mm thick steel plate. Already have a collection of cast wheels pictured. The big one is a little over the top but the smaller ones definitely show potential. Alternatively I have a slug of 5" steel I can bore and fit for bearings. I also had an old leaf spring to make the wipers with. Not pictured is some 3mm steel sheet I plan to use for the tub walls. As well as motors and reduction worm gear boxes aplenty. That is where the project is up to while I'm working on some others.