My jointer and thicknesser need to be moveable on casters. They get pulled out into an open area for use and then 'parked' in the corner when I'm finished with them.
The jointer was living on a general purpose wooden dolly I made years ago, but this was not purpose built so it didn't really grip the jointer base well, or fit it well, or have locking casters for safer use of the machine. The thicknesser had a set of three wheels that it came with, but it did not travel sideways. A bit of a pain in my small workshop!
So, I gathered some recycled steel, some casters old and new, and using just about every metalwork tool in the workshop, I welded up, machined, and spray painted some better machine bases with locking casters:
The video is quite detailed, but please let me know below if you would like any more info.