Sieg SX2 Plus build

[russell]

Time for another update:

I've drilled and tapped the column for the ballnut mounting and also at the back to lower the electronics enclosure to make room for the stepper motor.

Bolted the column in place and fitted the head to check the alignment of the column:

The side to side alignment was good at less than 1thou over 8 in. However the front to back alignment was out by 5 thou over the width of the table. I corrected this by fitting shims ( a few layers of kitchen foil) at the front edge of the column mount. OK., I know I should have filed and scraped the mounting pads but fitting shims was easier.

The end of the ballscrew was turned down and threaded M10 and a mounting plate made:

I had originally intended to tap the head to take the ballscrew but decided it would be easier to make slight positional adjustments with the mounting plate. The plate is tapped to take the screw and a brass grubscrew was fitted to lock the screw to prevent rotation.

I had originally intended to use an angular contact ball bearing in the ballnut assembly but couldn't find a suitable one so I used a normal bearing backed up with a needle roller thrust bearing like this:
ballnut_assy.dfx The spacer is to ensure that the thrust from the thrust bearing is taken on the outer race of the ball bearing.
Note also that I have threaded the end of the bush and made an adjusting collar (again with a grubscrew to lock it) to allow the preload on the thrust bearings to be adjusted. This isn't very well detailed on the drawing but can be seen in the picture of the parts:

Finally the parts assembled:

Just have to make the support now.

All for now
Russell.