Cooke Portrait Anastigmat Series IIE 15" knuckles repair info

**thegreatcornholio** · 14-Jan-2016, 08:34

Hi everyone,

I have a 15" Cooke Portrait Lens of the series IIE with a broken screw that holds the knuckles. Has anyone ever repaired a loose brass knuckles of that type of lens?

Thanks in advance!

**8x10 user** · 14-Jan-2016, 09:20

Send it to SK Grimes, they did a great job rebuilding the SF drive on my Universal Heliar.

**thegreatcornholio** · 14-Jan-2016, 10:05

I wrote to SK Grimes. Maybe I'll find a repair service in Germany...

**goamules** · 14-Jan-2016, 13:46

Getting Grimes to repair a sheared off screw, is like getting NASA to fix a flat tire on your RV. It's a screw. I'm sure someone in Germany can fix it for you for 5Euro or less!

**8x10 user** · 14-Jan-2016, 14:03

Oh it's just the handle and not the SF drive, I must not have been fully awake when I made the post.

Grimes redid an entire drive mechanism for me at a very reasonable price.

**thegreatcornholio** · 14-Jan-2016, 23:14

Well, I'd do the repair by myself, but I don't know exactly how.

You have to remove the whole front barrel in order to replace the screw in the inside of the barrel.
Attachment 145130

**goamules** · 15-Jan-2016, 06:58

Have you tried? Anything that was assembled, can be disassembled. The front will screw off. I don't have one of these, but all lenses do. The glass either comes off with the hood, or will be able to unscrew next.

**Tin Can** · 15-Jan-2016, 10:03

If you do fix it yourself, seek advice on screw retention.

Don't slop glue on any threads or the curse of 1000 years will be upon you.

Joking!

DIY is great with research.

Good luck.

**8x10 user** · 15-Jan-2016, 10:35

I'm playing with a 13" knuckler now, it does not look nearly as easy to take apart as the non knucklers. The rear element unscrews but it appears the front element requires a spanner wrench to open which is risky as a slip up can lead to badly damaged glass. Everything else that I turn seems to be locked or sets the aperture/soft focus. If you have a very steady hand you can try to take yours apart with a spanner wrench. It might be worth sending to an expert with experience and insurance as it is very valuable lens.

**Louis Pacilla** · 15-Jan-2016, 11:37

The IIE version is EXTREMELY EASY to disassemble.

First remove front element then remove the built in lens hood this holds the outer barrel (w/ knuckler) in place. Once the hood is removed you can work the outer barrel off the inner barrel and you'll then have access to the pair or in your case one screw holding the knuckler on the outer barrel. You can try to locate a duplicate or send the screw out to have a matching screw machined if that's the only way to get hold of another matching.

I had several other digi snaps of my 15" Cooke IIE when I serviced the soft focus device/movement but can only find these four now.I guess the others disappeared in cyber land to frolic too and fro hand and hand w/ all my other missing digi snaps.

****If you are going to remove old grease and re lube your soft focus device then make sure you remove all three elements including the center element which should easily unscrew from inner body and is in it's own metal retaining housing as the front and rear elements are. You can see all three elements in their metal housing in the second photo as well as the hood which again is what keeps the SF device in place when lens is complete.

You can see how easy the screws can be accessed in the last photo. The screws are on the back side of the outer barrel on the other side of the knuckle device . The screws or screw in your case is a brass trumpet head screw (not sure of the screws specs) which is counter sunk so the screws do not make contact with the inner barrel when the SF adjustments are made.

The third photo shows the pegs that runs through groves cut in the inner side of the outer barrel. these are the places where you will want to apply a fairly thin application of a non migrating grease. as well as a very thin coat of the same grease on the contacting barrels. The pegs are attached to the moving element and when the outer barrel is spun the pegs move in the groves of the outer barrel moving the and changing the element spacing for SF adjustment.

Again The 15" Cooke IIE is a VERY EASY Cooke Portrait lens to disassemble making getting to the screws holding the knuckler in place and most other parts of the lens pretty simple to work on. If you have any trouble feel free to PM me and I'll try to give what other guidance I can but it should be fairly simple. Just take your time and locate the proper replacement screw so it holds the knuckler correctly and is counter sunk so the screw doesn't cause any internal damage to the SF device.

Hope this wordy post makes sense & helps you successfully make the fix .

Peace