Repairing EF 50mm 1.8 II

[gosu]

I have damaged my EF 50mm 1.8 II lens and in need of  a repair.

A little accident during my  hiking trip got this little lens slightly damaged. The inner part is loose as you see it in the picture and need to be stationary. It does slide in and out when I play with it and when I put it in MF it still takes good pictures. In AF it does not focus well and hard to take a good picture. Of course this is out of warranty and not worth to have it serviced. 

My question is how can I attach the inner piece? If I "glue" the inner part of the focus ring to the body, will this still work?

I have attached a picture for reference. 

TIA,

Gosu

[ScottyP]

Hard to look at that. Try to remember the good times you and the lens had together, and always picture it in its strong healthy times, not like it is now. But now the lens is suffering and you owe it to the lens not to put it through any more. Let it go.

Someday, when you are ready, there is a fresh frisky new 50 f/1.8 out there that needs a home. And it only costs $110.

[Skirball]

Can't tell from the photo.  You need to try to find what part broke and glue that (try a nice plastic epoxy).  I wouldn't glue the focus ring, I couldn't see that working.  But I wouldn't get my hopes up.  Those things are made cheap to sell cheap, they're not made to be repaired.  I'm sure you can find a refurb for cheap.

[gosu]

Thanks Skirball,

You can hold the focus ring and pull out the inner part to a certain degree.  Yes I don't want to glue the focus ring (inner part)  but as illogical as it may seem, looks like it's only solution to keep it from sliding out. If it don't work out then no biggie. 

Bigger pictures attached. 

[Skirball]

Interesting, looks like it doesn't glue on, but is a mechanical lock from the lens side.  Have a look at this vid, shows how to take it apart.  Might help you put it back together.

http://www.youtube.com/watch?v=15tUQhVMScc

I can't really have a good look at the video now, but I scanned through it.  Looks to me like you should secure it from the other side (camera side).  Did any of the screws come out?

[gosu]

Thank you for the link!  

Apparently there are many tinkering / fixing this lens. I've found a pdf version: 

http://web.media.mit.edu/~bandy/rgb/disassembly.pdf

I didnt see any screws come off or any broken plastic tabs, etc..   I might have to open it up and see it. 

[Skirball]

Nice find, that's a pretty cool how too.  I'm guessing that the metal clasp (page 12) with the screw in it, broke or came out.  Based on both the PDF and the video once they take out that clasp they can pull out the front element kind of like yours.

[gosu]

I opened up the lens and tried to see if I can secure the inner part ...but was not successful. I guess the trick is to align the metal ring to the focus ring and that turned out to be difficult. After fidgeting for good amount time, I reassembled it back together. I wonder if anybody have tried this and got it to working condition. 

Took some shots to share the inner parts of the lens: 

Notice the metal ring that I'm having trouble with: 

The ring!

AF/MF switch plate that was attached with double side tape. 

[gosu]

Scott,

I didn't get much use out this lens and wanted to see if I can fix it. If I can't then I'll just retire this little fella.