Pancolar M42 Stuck Focus

William · Joined: 26 Nov 2009 Posts: 489 Location: London

I have Pancolar 50 1.8 in M42 mount with a very tight focus ring, it comes off the body if rotating anti-clockwise. Does anyone who has dismantled this lens know whether I will have to completely dissasemble it to fix the problem. I am wondering if the focusing helicoid is reasonably accessible. What is used to free it if it is full of gunk as I suspect it may be?

ludoo · Expire: 2011-12-05

Zebra or later version? I have opened the Zebra, and if you take pictures along the way and don't break the aperture linkage like I did, it's pretty easy. You have to remove the collar around the lens mount and go from there. There's a thread with pictures from a few months back.

William · Joined: 26 Nov 2009 Posts: 489 Location: London

It's a Zebra and apart from this issue in very good condition. I have found your thread from March but looking through that, and others, there are no photos of the helicoid that I can find. Tomorrow I will open it up and take a look.

ludoo · Expire: 2011-12-05

Once you get to the point depicted in the photo, it's easy to separate the helicoid. From the other thread

William · Joined: 26 Nov 2009 Posts: 489 Location: London

Thanks for the pointer on marking infinity, I've come across that before when reassembling practice lenses before and it's a pain. There must be multiple Zebra types as mine is different to yours. The section with the hyperfocal markings is shallower, there is no "Made in DDR" on the barrel or the pins? sticking out on the bottom.

martinsmith99 · Expire: 2013-11-18

If you're fine with taking the lens apart, all well and good. I prefer to try some lighter fluid 1st and see if this cures the problem.

William · Joined: 26 Nov 2009 Posts: 489 Location: London

How do you get the lighter fluid there without opening it? There's maybe 1 or 2mm of clearance under the focus ring.

martinsmith99 · Expire: 2013-11-18

Yup, just pour a few drops inside the focus ring and it will find its way in, work the focus back and forth. You may have to do this a few times. Then I mix approx 1:5 oil to lighter fluid and use this for a more permanent fix.

Probably not the right thing to do, but I've fixed a few lenses and cameras like this and destroyed a by few opening them.

William · Joined: 26 Nov 2009 Posts: 489 Location: London

I tried with Ronsonol lighter fluid on both the Pancolar and a Pentacon 50mm, the Pentacon is now very usable but the Pancolar is still stiff. When I can I will try some Zippo fluid as it is cleaner and leaves behind less residue. Have just bought a �10 Tessar with rough focusing to try disassembling and relubing with lithium grease. If that goes well I will try it with the Pancolar.

martinsmith99 · Expire: 2013-11-18

I use Zippo with a few drops of 3 in 1 oil. Glad it worked on one. Give it a few goes as I have had to do the same a few times before it fixes them.

enzodm · Joined: 11 Sep 2010 Posts: 350 Location: Italy

I have a Triotar with stiff focus; I thought -without doing it- at letting some fluid penetrating the tight room towards helicoid to soften it, but never found this possibility described (so I never done). This thread is convincing me, I'll try (unless there is some contraindication for the Triotar). Thanks.

martinsmith99 · Expire: 2013-11-18

The thing to remember is that the stiffness is caused by the grease drying out. The lighter fluid will also dry out rather quickly which is why I add some oil to it. I've no idea how long the `repair' will last, but I have lenses I used this treatment on working fine 12 months on.