About the Arm Mount for the Ball Screw Z-axis
We made the new arm mount so the ball screw column will be rigid. P/N 56442 is basically the same as the arm mount P/N 56440 that is on our NexGen mill. The difference is that we have drilled and tapped the four mounting holes so the column bed will now mount directly to the arm mount. You can either buy the new arm mount from us, or you can drill and tap the four 10-32 holes in your existing arm mount (Click the Instructions tab to download the specs).
This accompanying photo shows the Arm Mount attached to the mill column.