PDA

View Full Version : IKONTA 520 lens removal



Spottymaldoon
09-26-2008, 07:12 PM
I have to remove the second lens (counting from the front) from the Tessar combination in this f3.5 camera. I made a tool that has the shafts of two 1 mm drills to engage with the two holes in the lens mount (please see picture below):

http://richardleveson.com/IMG_0584.JPG

and so exert a CCW torque to (I wish!) unscrew this lens from its seat. BUT, the force I am having to apply seems too much and I am wondering if this lens is meant to come out another way? By my efforts, I have dinged the lens mount somewhat and don't want to make matters worse.

Please advise!

Spotty

elekm
09-27-2008, 07:16 AM
You're correct. Sometimes, it takes considerable force to remove this rear element. You might want to try an old trick: Try to tighten and then loosen. This sometimes works, but of course could make it worse.

Paul Goutiere
09-27-2008, 07:54 AM
Micro Tools sells wrenches called "flexicamps".

Measure the outside diameter of the lens and order the appropriate "flexiclamp". They will
not damage the delicate soft brass (if used very carefully) and enable you to exert considerable force.

elekm
09-27-2008, 08:45 AM
Sorry, meant to say "middle element," not rear.

Spottymaldoon
09-27-2008, 12:46 PM
Thanks for your moral support - I shall now proceed!

Spotty

JPD
09-28-2008, 04:09 AM
If the abouv doesn't work, you could always put the camera in the freezer for a while, then warm the outer ring in the shutter with your fingers, and then try to unscrew the lens element. That works sometimes.

Spottymaldoon
09-28-2008, 10:29 AM
Thanks very much again. I shall remake my lens-wrench with some masking tape to protect the mount from scratches and give it a good hard turn. I am so lucky that the Canada balsam bonding the rear doublet of the Tessar is unblemished: however there are strange stubborn stains on the interior lens faces which I removed with <gulp!> Brasso - and it seems to have worked!

My shutter is working fine for the longer times but the ring won't turn past 1/100 sec.(the quickest is 1/300 sec.) - has anybody encountered this problem? I rather dread to take the mechanism apart.

I have refurbished the leather nicely, following advice here, but I have some edges where actual leather has chipped away and I should like to find a compound that can fill in those missing chips - somebody had mentioned 'latex' but I am unsure where to find that and also whether it will 'take' the black dye?

Again, your advice will be much appreciated.

JPD
09-28-2008, 03:15 PM
My shutter is working fine for the longer times but the ring won't turn past 1/100 sec.(the quickest is 1/300 sec.) - has anybody encountered this problem? I rather dread to take the mechanism apart.The shutter has a booster spring that engages when you set it to the fastest speed. It can be rather stiff.

Spottymaldoon
09-28-2008, 05:16 PM
Hooray! Emboldened by the good people here I have removed the lens - you have no idea what a thrill it was to feel that sucker coming loose as I held the knurled shutter housing in a gorilla-like grip and put the torque to my home-made wrench- many thanks to those who responded so helpfully. JPD, you also emboldened me on the stiff shutter and, sure enough, I applied a bit of extra torque and now the 1/300 sec. speed is working fine (thanks for the pictures too) - would you disagree with the use of a tiny dab of lubricant on that cam?