Sieg SX2 Plus build

[russell]

Getting there at last.

Made the support for the ballnut and motor for the z axis:

Sorry, that's not a very clear picture. The side cheeks are rebated so that I could sit the mounting plate on top and slide it fore and aft to get the best alignment with the ballscrew (with the head in it's highest position). The assembly was then clamped and the position of the fixing screws was spotted through onto the sides of the mounting plates for accurate drilling and tapping. Side to side alignment is achieved by slotting the screw holes in the ballscrew bottom mounting plate slightly to allow adjustment.

The stepper motor is mounted on a 5 mm ali plate which can be slid back and forth on two arms at the back of the mounting plate to adjust the belt tension before being clamped in position.

I checked the backlash of the z axis and could not measure it on my dial indicator. It is certainly less than half a thou. However, leaning heavily on the head with it at the top of it's travel (with the gib tightened) gave me about 3 thou movement which must be due to the column flexing. If I'm going to want high accuracy I will have to keep the cuts light but then it is a light machine.

A replacement spindle motor mount was made to move the motor forward sufficiently to clear the ballnut and pulley assembly:

The observant amongst you may notice the skinny drive belt. This wasn't part of the design. I ordered a 15 mm belt from the French RS Components and they sent a 9 mm wide one instead due to an error in their on-line catalogue. Rather than sending it back I am using it and doubt that I will overload it in use. The spindle drive electronics have been mounted lower down on the column to clear the z stepper motor and connected up. The spindle still works

Just the x and Y limit switches to fit and look for a cheap second hand computer. Then the learning will really start!

Russell