Upload & Sell: On
Still digging into the FD bin for lenses to convert over, and I figured this one would be pretty straight forward. Other than being very careful with measurements (measure twice, cut/mill/turn once...), the toughest part was getting the shift leadscrew out. The endcollar lock screw on the leadscrew had a pretty strong adhesive on the threads, so the solvent of choice was MEK (be careful with that stuff...).
I started out with a backplate thickness of 5.82mm, so I milled it down to 2.50mm, and milled the M42-EOS adapter from 1.42mm to 1.20mm. The .12mm undercut ensures that infinity focus is maintained after heat/pressure bonding with J-B weld between the backplate and lens mount. Also, the joining ring and its' mount needed to be shorted (because of the thinning of the backplate). I "hexed" the joining ring and burnished both female and male threads with a SS radial brush to help reform the threads...it worked perfectly. Everything threaded fine and tightened up very snug. The original spring for the rotation detent was replaced with a re-wound ball-point pen spring, and provides the same holding force as the orginal. The M42-EOS mount has a "holding hole" for it to reside in.
Finished photos will be posted Sunday afternoon, and hopefully some shots also. Last time I used this lens was on a T90, with Kodachrome 25...got to find those slides and get them scanned.
Edited on Feb 26, 2011 at 09:50 PM · View previous versions