[AlexiaMorinigoSpalding]

The objective of the CNC retrofit team is to repair and enhance a used Shopmaster Eldorado Bridgemill that has not been used for several years. The mill must be fully functional with a 3-axis configuration and lathe capabilities.

We have been able to convert the x and y axis into CNC but are having trouble with the z-axis.

Right now, we can manually control the quill z-axis with the silver mill fine feed handle on the right of the quill. We want to move the z-axis with a motor using a lead screw in the axis bracket. The quill doesn't move when we push or pull on this bracket, so we believe that directly attaching a mechanism to it could damage or break the existing mechanism. We are hesitant to open the housing to understand the inner workings. Is it necessary for us to open the mill and disengage the fine feed handle to move the quill with a motor?

[instructor37]

On that machine there is a bracket that holds a NEMA 34 stepper motor vertically. They used to sell an optional CNC drive set which included a ball screw which was driven by a pulley which was driven by another pulley on the stepper. The ball screw atteched to the bracket around the quill and drove it directly. You would pull the center knob of the drill press function out so the quil would travel freely.