Our products are tested before they leave the wood shop. Sometimes wheels and other parts can stick due to humidity. Humid conditions can make the wood expand and thus limit the movement of some parts. We first recommend that you work the part back and forth. After doing this over and over again for a while the part will usually loosen and spin or move more freely.
If the part is still not moving freely, the item may have gotten wet or it is in a humid environment. Let the item dry and take the item into a less humid environment and leave it there for a few days. Again work the part back and forth and the part should move freely once the wood contracts.