This message is cross posted on several web sites. The Z axis on my Bridgeport BTC1 has acted up. Seems the encoder used (past tense) an incandescent bulb. I once found an editorial where someone replaced one of these can type BEI encoders with one of the new, miniature all solid state encoders. They had a complete pictorial on how to do it, although, as I recall, they didn't tell much about the bearings and what kind of hardware they had to use to adapt. Does anyone recall this article, and where it is? I'd love to ask the editor some questions.