Canon FL 100/3.5 repair,need help

[mo]

Hi All,
I had just received this lens from a friend in the States,long story short I thought I had mounted it properly on the M4/3 adapter. I gave it to my son to try on the G1, and the lens popped off and hit the ground with a bang. I could not see any damage at first, but had troubles trying to mount the adapter back onto the lens.The lenses chrome rear ring would only turn a few mm and not lock the lens in place on the adapter.
After looking at it and becoming more and more frustrated. I finally came across this very slight dent/depression, so subtle I had missed it up until this point.

Question is can I repair it myself by taking off the rear chrome ring (is it easy to do? ) or do I have to send it to a repairman to fix it.? Thanks for any and all help given,I am just so disapointed in having just received the lens and having it dropped (not my sons fault,I was encouraging him to enjoy my hobby as well) It's just one of those things that happens.
#1

#2 This slight depression is located right over one of the 3 flanges,I also believe the chrome ring has lost its shape everso slightly

[Lightshow]

There is a screw on the lens' lock ring that will permit the lock ring to be screwed off the body, that should simplify the repair.

[mo]

Do you know if there is anything attached to this lock ring? I am worried if I start unscrewing things I may cause more problems than I can handle.

[pavko]

Judging from build of other FL lenses there is nothing. It's safe to unscrew lock ring.

[Lloydy]

I've got a bit of a dead Canon in front of me and I have removed the single screw on the side of the breechlock ring and that does not ( on this lens, and I have no idea what the lens was other than it was genuine Canon ) allow the ring to come off.
Looking down on the lens mount surface, inside the breechlock ring, there are three screws - JIS 00 - that are so tight I can't move two of them, in the third screw there's a broken tip of a screwdriver, probably why the lens is in bits and I've just got the mount!
However, this lens has a button ( to lock the breechlock ? ) that sits in a recess and effectively controls the amount the breechlock ring turns, I think that without that button the ring would unscrew off.
It's been a long time since I had one apart and put one back together, and I know there's a world of tiny balls and springs in there, and I'm not sure if they are likely to fall out.

I would try a bit of leverage, get an old screwdriver and bend the tip right around, heat it until red hot and bend with pliers and then tap it into shape with a hammer, allow to cool naturally. File it and adjust it until it hooks under the dent and then apply some pressure. The design of a lever like this applies the pressure to the ring that you are trying to straighten so it shouldn't force anything. It might just pull the ring back in to shape?

[David]

FWIW, I agree with Lloyd's approach as a first start since it allows the repair to be performed without dismantling. The you over-pull the mount, you can always gently press it back into shape.

[mo]

Great idea Lloydy, I would prefer to try your idea,I will have to check that I have everything that I need.

[mo]

While I was waiting for replies on this thread.I had sent an email to the man who usually repairs/cleans my lenses, asking is there anything under this ring that is attached and he said no. It's just a matter of unscrewing a solitary screw and unscrewing the chrome lock ring. (thanks Pavko)
Once this lock screw is removed (on my lens it's the only screw on the chrome ring), the chrome ring turned two full turns (I turned it slowly, because I have missed when the lens disengages before and its no fun).
I used the screw hole of the removed locking screw as my starting point, when counting how many turns it took. I also had pre marked where the chrome ring stopped when you turn it to lock anything on the lens(using the red dot),and also where the lock screw was located when you turn this ring (start and finish).

I may have to go back and re panel beat, as I still cannot lock the M4/3 adapter on the lens (it goes on nicely with out the lens attached)

Here are some piccies of what I did and my tool set...if you can suggest a better tool set I am all ears,I had to use what was available.

#1 The tool set, and yes that is a Kodak flash holder camera bracket and a Hammer

#2 The naked lens mount without the ring from the front

#3 The area where the lock screw does its job.

#4 The Damage

#5 The adapter and the chrome ring together at last...or so I thought,add the lens back into the equation and I still can't marry the two!

#6 The panel beaten ring,a bit lumpy but what do you expect when you have a flash bracket instead of a proper "Punch"

[pavko]

I'm guessing here but it's because of the pin that should engage aperture lever. Lens base is touching it and can't protrude far enough so lock ring can engage against lugs.

[mo]

No, it was a dent in the lenses silver mount, image #4 that prevented me from locking the chrome ring onto the adapter.The two parts kept hitting one another until I bent/hit it back into shape so they could then slide over one another...seen in image #5

[pavko]

I misunderstood your description then. I thought that ring was straightened and lens sill could not lock. Then I thought about the base as I had similar problem with one of my FL lenses.
I hope you will be happy with 100/3.5 - it's really great lens. Enjoy and please share with some samples.

[mo]

It took me two times before I got it right I think I have samples somewhere on the forum, but unsure if they survived the recent forum crash.