If your bearing does not turn anymore, it is possible to repair the frozen bearing.
You can carefully remove the shield on one side of the bearing. Use a very thin blade to remove the shield.
Once the shield is removed, use WD-40 or kerosene to wash out and clean any debris that exists within the bearing. WD-40 is a cleaner, not a lubrication agent.
You will then need to re-lubricate the bearing. Packing grease into the bearing will provide good protection not allowing too much metal on metal friction. There will be a layer of grease separating the ball bearings from the inner and outer races.
If you have a production environment, you may want to purchase extra bearings so that you will not have any down time.
If you have a rubber shield, just pry it out using any sharp object, like a utility knife. If your bearing has a metal shield, there may be a retaining ring along the outer race keeping the shield in place. Simply remove the retaining ring and the metal shield will fall out easily. If the metal shield does not have a retaining ring, that shield will not be able to be removed and a new bearing will need to be purchased to replace the frozen bearing.
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You built the first 36 inch Blue Chick for me. One of the V-Groove bearings on the X-axis froze. Is there a method of repairing this? Or do I order another and a spare. If so, what is the procedure to repair or order?