Optical Table CNC Lathe - New linear bearings
To get stiffer axes for the lathe, I am going to toss the weak Parker stage and use the cross roller stage as the cross slide instead. To replace it in turn, I am using large recirculating roller bearings of type IKO LRX45.
I used the lathe to make a helper part to drill the mounting holes. I did this in two steps. First, I made the minimum amount of holes to mount everything to see if it would fit together well. Then, I went and put in all the remaining holes.
I drilled successively larger holes in the helper part for successively larger drill bits. Finally, I used the 10x1.25 mm tap to tap the guide itself to help me tap the holes.
Still, I broke or damaged several drills and finally the tap too.
In the end, all the holes were in place, though:
The plan was to mount the axes exactly along the table, and I originally assembled the lathe that way too:
But it turns out that this approach wastes a lot of the potential movement of the rails because the spindle and chuck take up the space.
To mount the spindle, I first made a template of the spindle mounting holes in Inkscape and then slid it around until it was compatible with the existing holes.
Luckily, my mini drill press was a good enough fit to make these holes. And the rails made a nice guide for the tap:
And with the holes in place I could mount the spindle to get a better idea where the rails should go:
The tap is at the end of its life too:
I made the cross slide on the drill press from a piece of aluminum and then mounted the cross-roller bearing based Parker stage onto that. Then I made an adapter plate out of a piece of MIC6 aluminum plate to hold the tool post.
This improved the surface quality a lot, but it is still not as nice as I like. However, it is not obvious where the remaining chatter comes from. For that I needed new instrumentation