The Carl Zeiss Jena 180 f2.8 is a monstrous piece of glass and metal. Because of its Pentacon 6 mount though, it is an easy target to turn it into a Nikon, a little easier than the Pentacon 135 2.8 and much easier than the Carl Zeiss Jena 135 f3.5. I fount one on eBay for a mere 100 Euros including a -rather smelly – case which you can also use as a tall hat. The lens was stored in the case and probably not used for years. I found no fungus, just a lot of dirt and oil from the aperture blades and the helicoid. Disassembling is a bit tricky because of the weight of the lens and it pays off to consider that letting the huge blob of glass fall off will ruin your floor and/or break your foot. So, if you decide to dismantle the thing, do it on a large surface covered with something soft.
Cleaning and re-greasing such lenses is a good idea. it may not be necessary to completely remove the helicoid, but if you do take care to put it the same way in as it came out. If you want to clean the helicoids, you can either follow the warm water/soap solution or my lazier way: there are some special tissues for cleaning your greasy hands. These remove grease pretty easily but take care not to leave fibers behind. After cleaning apply modest amounts of grease and work the helicoid until it feel s right, whatever that means.
I also tried to repair the fix of the lens which is attached to its collar. This is really one weak point of this heavy lens. The collar breaking lever just pushes a small metal tab on the lens which is supposed to block its rotation. I do not know whether there was another arrangement in place originally but this one does not work… I am still looking for a nice way to stop the lens from revolving in its collar.
The mount is the easy part, all you need is a Pentacon 6 to Nikon camera adapter. Attaching the Dandelion chip is easy as you only need to stick it at the back of the lens. There are a couple of issues though: the lens is pretty heavy and you need to be careful. Although I attached the chip and tested with the adapter only, when i mounted it on the lens, after a couple of times of mounting/unmounting the lens, the chip broke off. there was no damage to the chip but it was obvious that the weight of the lens required some more glue around the chip to make it more rigid. It is inevitable that when removing the lens, sometimes it abruptly tilts with repsect to the camera and the chip hits the mount. This is not the case with any other lens I chipped. So all you have to do is to make some hatch pattern on the mounting tab and the chip to make the glue stick better and beef up the glue around the chip. This made it more stable. Another problem I noticed is that sometimes the chip does not make contact. It turns a bit more than it should to the right. This may be due to the heavy lens or due to the adapter’s stop screw. Just make sure you keep it to the left if you don’t get the right lens readings.