TIL the hard way that a dirty helicoid can misalign your whole focus ring

I was servicing a Pentax Spotmatic last Tuesday in my garage, trying to fix a stiff focus ring. After I cleaned the helicoid with lighter fluid and regreased it, the ring turned smooth but the scale marks were off by about 3 feet at infinity. Turns out I mixed up the threads when I put it back together and had to take it apart three times to get the pitch right. Has anyone else dealt with focus ring reassembly going sideways like that?

2 comments

2 Comments

oscarcooper21d ago

Ngl that sounds like user error, not a helicoid problem.

nina18021d ago

Wait, how is it user error if the helicoid is literally slipping when you turn it? That's a physical malfunction, not someone pressing the wrong button.