A few weeks back we changed out the six regular wheels that moved the Tardis Observatory off from the telescope, to four inverted V wheels on an angle iron rail.
Since the structure of the building is not as good as it could be, we thought it a good idea to add two more wheels in the centre to give it more support.
These are the two new wheels being mount to a 2″x4″x7″ long wood plate. They were then inserted and secured to the structure underneath.