jimford
Newbie
I recently bought an Industar 61 for my Fed 2. It's nice and clean, but the focussing was very 'gritty' in feel - as if there was sand in the mechanism.
I stripped it down, but there was no sand on the helical threads. What I did find was that the 'anti-rotation' steel screw that operates in an alluminium groove when focussing had worn the aluminium, preventing smooth travel. As the lens showed little evidence of hard use, I suspect that the lubrication was inadequate in this area.
I used a dead smooth swiss file to clean up the wear in the groove and pin, and it now operates smoothly. I've now only to decide on a suitable grease in order to complete assembly.
Jim
I stripped it down, but there was no sand on the helical threads. What I did find was that the 'anti-rotation' steel screw that operates in an alluminium groove when focussing had worn the aluminium, preventing smooth travel. As the lens showed little evidence of hard use, I suspect that the lubrication was inadequate in this area.
I used a dead smooth swiss file to clean up the wear in the groove and pin, and it now operates smoothly. I've now only to decide on a suitable grease in order to complete assembly.
Jim