A wheel arrangement (10) having a first support arrangement, a second support arrangement a fixed framework member and a moveable support member having a substrate contacting wheel, the first and second support arrangements are moveable with respect to the fixed framework member, the first support arrangement and the second support arrangement are located substantially transversely to each other and cooperatively interact with the fixed framework member whilst permitting the moveable support member to move with respect to the fixed framework member, so that movement of the first and second support arrangements permits the substrate contacting wheel to move with respect to the fixed framework member.
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