<p>Hi</p> <p>I found a nice Canon nFD 24mm F2 lens with a stuck aperture from ebay. I cleaned the aperture and now it works well but the focus mechanism moves a little.<br> I disassembled as much as I can but don't know what to do next. No screws or anything is visible. I do know that there are rails in the focus mechanism and inside a rail goes a metal rod with plastic over it. Well the plastic has run out and due to that, there is small movement in focus if you move the camera. Also, infinity focus isn't always available until i shake the camera so that lens is facing the sky and camera lcd is facing the ground, and then I let like the lens element fall 1-2mm down and then I can point and shoot, and its in focus. If I move the camera a little bit, its then out of focus, and I must adjust focus again.<br> The circular thing in the middle of the lens is what moves a little.<br> The thing moves because the plastic has worn out from rails and it allows small movement. I can see the pins inside the rails from small holes inside the lens housing and if there were the plastic left, it wouldn't move.<br> Well, long story short, does anyone know how to open the lens "helicoid", or focus system? I need to get to the metal pins inside the rails and recoat them with sugru or something. Or solder some tin on them to make them just a bit thicker.<br> Here are pictures. All parts like glass and aperture have been removed and just the focusing mechanism remains. But its a mystery how it opens.<br> On picture 1, I can see a metal rod and its in a rail and the rail goes like vertically (if lens is pointed towards sky).<br> Picture 2 has more rails located inside the red circle. I can see old black plastic residues on top of them and some of it fell out when I opened the lens.<br> Picture 4 has the last parts I removed from the lens. Also aperture lever (shining metal colored) or what is it called is also removed and cant be seen.<br> Thanks is anyone can help.</p> <p>here are pictures:</p> <p><img src="http://i.imgur.com/GdTYC1E.jpg" alt="" width="600" height="800" /></p> <p><img src="http://i.imgur.com/SVMqN8a.jpg" alt="" width="800" height="600" /></p> <p><img src="http://i.imgur.com/sR7qYgf.jpg" alt="" width="800" height="421" /></p> <p><img src="http://i.imgur.com/DzYmo8K.jpg" alt="" width="800" height="547" /></p>
