Last year I installed a head riser for a Harbor Freight 6x26 milling machine. The work went without problems, and I believe that this is how the machine should have been built. After using the machine, I have found that raising the table up and down is somewhat of a PITA for a 79-year-old man. I finally found a z axis drive kit for a Bridgeport mill and installed it today. The installation went great, had to do some machine work but everything went without problems. Anybody that owns one of these mill types might want to investigate installing one of these units. My shoulder sure has given a sigh of relief. I have been really busy and have not been keeping up with this forum, I will try to do better in future. Good luck to all.