NikonGear'23
Gear Talk => Lens Talk => Topic started by: Zang on July 11, 2022, 14:09:59
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Hi all,
I am restoring very dirty Canon FD 85mm f1.8. I took apart the rear assembly (where you have the ball bearing and the aperture levers) and I cleaned it from dirt and oil. I am putting it together now and thinking its ball bearings might not need grease at all. Grease will catch dust and also it could get to the sensor in some situation. How is your experience, do you think I should put some grease in there?
Cheers,
Zang
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I suspect someone like Richard Haw can chime in with more expert advice, but I'd leave them alone, because grease can induce drag.
The aperture mechanisms in the lenses and converters I've taken apart over the years were not tightly assembled or preloaded, and never showed signs of grease, and I suspect that at most they had a tiny bit of some light oil, and even that was uncertain, but if present was probably something very light and special, like clock oil.
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Thanks Matt! That was also my thinking. This is not a car bearing so I do not expect a lot of stress nor movement. I'll wait a bit for any potential input and will put the rest of the lens back together :)
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Ok, the lens is back in one piece.
There was a funny (well, not really funny) story to tell... I think Rick mentioned in one of his articles but I learned it the hard way anyway. I poured all the balls to my workshop carpet. A magnet came handy but I am sure I lost a few balls.
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At a far older age than I would care to admit, I have finally gotten into the habit of doing things like this over a big roasting pan.
What never fails to surprise me is how far, and in what unlikely directions, a little part can roll, bounce, or simply be carried off by invisible elves. Or tomtens, depending on where you do it.
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LOL
You are right again... I found two more balls that 'jumped' a bit further from where they were dropped. The worst part was, when opening the assembly to put those two in, all the balls got poured out from the casing and I needed to start over again.
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These days getting dressed and undressed gives me similar challenges. Lost items of clothing every day!
But when I do surgery on lenses, and especially computers, I have a tendency to lose track of things.
It’s either my age, or the gin :-)
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Make sure the steel balls and the ball races are completely clean - There is no need for any oil on these aperture leaver connections.
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I recall pulling a lens apart and lossing some of the balls. A local bearing shop sold me about 50grams (about 2oz) of identical sized steel balls (their minimum order amount), so this workaround is worth keeping in mind if the unthinkable happens. Also line the tray with some microfibre cloth to stop the bounces.
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These days getting dressed and undressed gives me similar challenges. Lost items of clothing every day!
But when I do surgery on lenses, and especially computers, I have a tendency to lose track of things.
It’s either my age, or the gin :-)
:) :) :)
I did lose a few parts when rinsing my lens element in my sink after dipping them in mineral spirit over night. That was a painful lesson :(
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Make sure the steel balls and the ball races are completely clean - There is no need for any oil on these aperture leaver connections.
Thank was exactly what I did. Thanks Erik!
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I recall pulling a lens apart and lossing some of the balls. A local bearing shop sold me about 50grams (about 2oz) of identical sized steel balls (their minimum order amount), so this workaround is worth keeping in mind if the unthinkable happens. Also line the tray with some microfibre cloth to stop the bounces.
Oh yeah, I put towel paper when doing the second attempt. All is good now, thanks for the tip :)
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You may add a little drop of watches oil, very little, on the end of the needle. Please put it on the path of the balls. Do not let the oil spread on the aperture - be careful. Good luck! LZ
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You may add a little drop of watches oil, very little, on the end of the needle. Please put it on the path of the balls. Do not let the oil spread on the aperture - be careful. Good luck! LZ
I do not have watch oil :) The balls expose to the back in some part of the case so if I get the oil in the future, I might consider putting some there like you suggested. Regarding spreading the balls out, as soon as I unscrew the case, they pour out and it is very difficult to prevent it from happening. It is easier to put them back than trying to keep them in the path when opening the case.
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You may add a little drop of watches oil, very little, on the end of the needle. Please put it on the path of the balls. Do not let the oil spread on the aperture - be careful. Good luck! LZ
Yes, that also works ;)
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I recommend what I see as an improvement on the use of a needle as a watch oiler.
As shown I've taken a length of ~1,5 mm diameter brass wire and flattened both sides of one end with a small hammer so that a wedge was created on both sides that tapers down to ~0,25 mm.
Brass being diamagnetic (unlike common steel or a few bronzes) can't transfer any magnetism to the ball bearings. But more importantly the idea here is to create a very thin oil film. A droplet of oil per ball is far more lubrication than is necessary! To use this oiler dip the tip of the oiler in the oil bottle (or cup) then tap the tip of the oiler on the rim of the oil bottle (or cup) so that nothing appears to remain. The flats of the oiler will retain a film of oil. Holding each ball bearing in a pair of nylon tipped tweezers touch the tip of the oiler to the ball in two places. A sufficient amount of oil will be transferred to the ball.
Applied like this the an appropriate grade of any of the better currently available synthetic watch oils will remain where placed and not migrate for many years to areas that the balls do not touch.
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I recommend what I see as an improvement on the use of a needle as a watch oiler.
As shown I've taken a length of ~1,5 mm diameter brass wire and flattened both sides of one end with a small hammer so that a wedge was created on both sides that tapers down to ~0,25 mm.
Brass being diamagnetic (unlike common steel or a few bronzes) can't transfer any magnetism to the ball bearings. But more importantly the idea here is to create a very thin oil film. A droplet of oil per ball is far more lubrication than is necessary! To use this oiler dip the tip of the oiler in the oil bottle (or cup) then tap the tip of the oiler on the rim of the oil bottle (or cup) so that nothing appears to remain. The flats of the oiler will retain a film of oil. Holding each ball bearing in a pair of nylon tipped tweezers touch the tip of the oiler to the ball in two places. A sufficient amount of oil will be transferred to the ball.
Applied like this the an appropriate grade of any of the better currently available synthetic watch oils will remain where placed and not migrate for many years to areas that the balls do not touch.
You mentioned about diamagnetism, the balls were already magnetized when I collected them using a magnet. Was that bad?
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I recommend what I see as an improvement on the use of a needle as a watch oiler.
As shown I've taken a length of ~1,5 mm diameter brass wire and flattened both sides of one end with a small hammer so that a wedge was created on both sides that tapers down to ~0,25 mm.
Brass being diamagnetic (unlike common steel or a few bronzes) can't transfer any magnetism to the ball bearings. But more importantly the idea here is to create a very thin oil film. A droplet of oil per ball is far more lubrication than is necessary! To use this oiler dip the tip of the oiler in the oil bottle (or cup) then tap the tip of the oiler on the rim of the oil bottle (or cup) so that nothing appears to remain. The flats of the oiler will retain a film of oil. Holding each ball bearing in a pair of nylon tipped tweezers touch the tip of the oiler to the ball in two places. A sufficient amount of oil will be transferred to the ball.
Applied like this the an appropriate grade of any of the better currently available synthetic watch oils will remain where placed and not migrate for many years to areas that the balls do not touch.
Nobody recommended a drop of oil on every ball! One drop for all! On the ball path, if you read it correctly, with using of the needle - far less than your tool. LZ
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Let me be more specific.
Lubrication-
If you intend to use an oil such as Moebius V106, a general purpose thin film lube, Nikon's recommended procedure will work- at some risk of eventual migration of any excess lubricant to places where it is not desired.
On the other hand if you are using a modern "oil" such as Moebius Synta-Visco-Lube 9010-Film, a fully synthetic lubricant developed in part for use in cameras and optical instruments, the risk of lube migration over many years is truly minimal as the adherence of this product is excellent. Applied as I noted above you're transferring only a small portion of the very thin film remaining on the oiler to just two points on each ball bearing. The result will be substantially less than oil in the mechanism than a single drop spread around the race. The lubricant film, a fraction of a micron thick, is what minimizes wear and friction. Any surplus is wasted.
Magnetism-
As a general rule stray magnetism is not desirable in proximity to low power electronic circuits. What is present after use of a small, relatively weak magnet to control ball bearings in disassembly is likely to be harmless. That said, if I notice relatively strong magnetism is present I use a demagnetizer on the balls.
Bob
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Let me be more specific.
Lubrication-
If you intend to use an oil such as Moebius V106, a general purpose thin film lube, Nikon's recommended procedure will work- at some risk of eventual migration of any excess lubricant to places where it is not desired.
On the other hand if you are using a modern "oil" such as Moebius Synta-Visco-Lube 9010-Film, a fully synthetic lubricant developed in part for use in cameras and optical instruments, the risk of lube migration over many years is truly minimal as the adherence of this product is excellent. Applied as I noted above you're transferring only a small portion of the very thin film remaining on the oiler to just two points on each ball bearing. The result will be substantially less than oil in the mechanism than a single drop spread around the race. The lubricant film, a fraction of a micron thick, is what minimizes wear and friction. Any surplus is wasted.
Magnetism-
As a general rule stray magnetism is not desirable in proximity to low power electronic circuits. What is present after use of a small, relatively weak magnet to control ball bearings in disassembly is likely to be harmless. That said, if I notice relatively strong magnetism is present I use a demagnetizer on the balls.
Bob
Thanks Bob, I did not worry about the magnetic field affecting the camera's work either. I thought when the balls stick together, it might affect they way they are rolling in the path :)
I enjoy the technical knowledge you guys share here and I have learned a lot, but probably I over think about the bearing a bit. At the end, it only serves my manual aperture changing, no shutter speed priority mode in use at all, so I think I am good to leave them dry and clean.