Micro lathe Zero backlash* conversion

[John S]

Leave the chuck at 80mm, the spindle can't handle the weight of a 100m chuck.
Ring Ketan if you don't believe me.

[Jonathan]

Should not be possible to fail.

Quick methodology test...

One nut is bolted to the slide, the other nut is merely prevented from turning.

Yep. Although when I bored the ballnut mount on Z I didn't leave much clearance, so maybe the ballnut is skewing and binding somehow. Will have to investigate when I've got time.

Leave the chuck at 80mm, the spindle can't handle the weight of a 100m chuck.
Ring Ketan if you don't believe me.

That's rather annoying, especially since I started making the backplate yesterday. Have you tried it (not that I'm disputing your experience, just wondering)?
Looks like I need to get some external jaws for the 80mm chuck as they're missing.