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04-15-2018, 04:09 AM   #1
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Primoplan helicoid.

I need to lubricate the helicoid of the primoplan 58mm f1.9. There doesn't seem to be much information on how to clean these lenses, and what information exists is about taking the lens apart to clean the glass and the aperture blades. In my case thankfully the aperture and the glass are fine, but the helicoid is pretty stiff. Because of that, I don't want to take the lens apart from the back or the front, unless I have to. There is a screw on the focusing ring. Do you guys know if taking it out will get me to the helicoid?

Thank you!

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04-15-2018, 04:53 AM   #2
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I haven't serviced one of these... however, if you look at the following video, you can see what the lens looks like without the mount section:


My guess would be that if you remove that large set screw below the "Germany" marking, you should be on your way to removing the mount (perhaps it just slides off, or maybe it's threaded). After removing the mount, further visual inspection at that point should help in identifying what other screw(s) need to be removed to allow the helicoids to separate...
04-16-2018, 09:31 AM   #3
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I shouldn't have touched this... I lubricated the helicoid, but for some reason it is still stiff. Now I am having tough time putting it back together. There were to springs that stick out at 90 degree angle from the base of the rear element, and over those two springs sits the lens mount. Not sure how to put it back, especially now that I lost one of the springs! I was trying to compress it and it just flew out and got lost. And I lost infinity focus... On the positive side, now the lens focuses much closer than the original 75cm Why did I decide to do this???
04-16-2018, 09:51 AM   #4
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QuoteOriginally posted by IgorZ Quote
I shouldn't have touched this... I lubricated the helicoid, but for some reason it is still stiff. Now I am having tough time putting it back together. There were to springs that stick out at 90 degree angle from the base of the rear element, and over those two springs sits the lens mount. Not sure how to put it back, especially now that I lost one of the springs! I was trying to compress it and it just flew out and got lost. And I lost infinity focus... On the positive side, now the lens focuses much closer than the original 75cm Why did I decide to do this???
I've been in situations remarkably similar to this before now, so I can sympathise

Regarding the lost spring, the best advice I can give is to close the curtains in the room and use only a flashlight to light the floor at different angles. I've found a few lost components this way. Also, if you have any of those sticky rollers used for removing hairs from clothing, they're a good tool to sweep back and forth across the floor and pick up anything that you might not have seen.

Do you have any other old lenses you can raid for spares? Sometimes, the springs in diaphragm mechanisms can be pulled and stretched to make compression springs. I did that for an old Domiplan some time last year. Depending on the size of the spring, even one from a retractable ball-point pen might be a suitable donor part with a little work.

As I said, I haven't serviced a Primoplan before, but if you want to take some photos and PM me, I'll happily take a look and see if I can figure anything out. Beyond that, I'd recommend asking for help on MFLenses if you haven't already done so. I've had good help from those guys in the past.

6 Days Ago   #5
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Thanks for the support! I found the spring a day after I lost it. The springs go into these wholes in the side (photo 1)and the lens mount goes over them (photo 2). I am not sure how to put the lens mount over them. The lens mount itself can be taken apart, and it seems that the inner part of it should be over the springs (photo 3)
6 Days Ago - 1 Like   #6
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here are the photos

---------- Post added 04-17-18 at 07:29 PM ----------

I managed to put it together. The trick is to take apart the mount assembly, then slide the inner part of the assembly over one spring, then over the other and then to put the outer part of the lens mount back. Infinity focus seems to be there as well. I am not touching this thing again, even though it does not focus as smoothly as I would like, despite the lubrication...

---------- Post added 04-17-18 at 07:30 PM ----------

Thank you for your support, I really appreciate it!
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6 Days Ago   #7
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QuoteOriginally posted by IgorZ Quote
I found the spring a day after I lost it. The springs go into these wholes in the side (photo 1)and the lens mount goes over them (photo 2).
I once lost a small ball bearing for the aperture ring on one of my Soviet lenses while servicing it. It was an odd size, and I didn't have a suitable spare, so I had to reassemble the lens with a "clickless" aperture control... About a week later, whilst re-organising some things in my hobby room, I found the bearing by chance (and later re-installed it). It changed a couple of aspects of my servicing approach, though. Now, I always use a soft, light-coloured towel to work on, so components don't bounce off and can be seen easily. Also, any lens or piece of equipment that's destined for the junk heap, I tear it down and keep the screws, bearings and springs for spares.

QuoteOriginally posted by IgorZ Quote
I managed to put it together. The trick is to take apart the mount assembly, then slide the inner part of the assembly over one spring, then over the other and then to put the outer part of the lens mount back. Infinity focus seems to be there as well.
Well done! Sounds like a fiddly job... You have to wonder what the designers were thinking when they designed these little marvels

QuoteOriginally posted by IgorZ Quote
I am not touching this thing again, even though it does not focus as smoothly as I would like, despite the lubrication...
I know how you must feel... but don't let it put you off. This has been a learning experience, but you'll never forget how that lens comes apart and goes back together!!

QuoteOriginally posted by IgorZ Quote
Thank you for your support, I really appreciate it!
You're welcome. I'm always happy to help if I can, and sympathise if I can't
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