ฝัง
- เผยแพร่เมื่อ 11 ต.ค. 2024
- The focus ring was very stiff in my nice old lens, Minolta MC ROKKOR-PF 58mm 1:1.4.
I use some Isopropylalcohol 99% to clean the focus helicoid's, and then re-grease with a very light helicoid grease, grade #10.
Now the lens work's as it was new, and the focus ring is very easy to move.
Hi - excellent video and very informative! There are however, two suggestions I would like to make as follows:
1. use a small quantity of unleaded petrol to do the initial cleaning of focus ring components, which is a far superior solvent for grease than Isopropyl Alcohol [and you will simply be amazed at how much cleaner the rings are when using petrol compared to using Isopropyl Alcohol, because Isopropyl Alcohol simply cannot dissolve grease components which you did observe when you examined the helical ring after cleaning. Once cleaned by petrol then give the focus ring components a quick wash in Isopropyl Alcohol to remove any residual additives initially present in the petrol. [OBSERVE ALL of the REQUIRED SAFETY PRECAUTIONS WHEN USING HIGHLY VOLATILE, FLAMMABLE LIQUIDS SUCH AS PETROL AND particularly DO OUTSIDE IN THE OPEN AIR so that petrol vapours cannot accumulate AND totally ensure there are no sources of ignition anywhere nearby when cleaning the rings in this manner - NO RESPONSIBILITY for anyone who is silly-enough to short-cut or ignore these ABSOLUTELY ESSENTIAL SAFETY PRECAUTIONS! REMEMBER TOO, THAT STATIC ELECTRICITY ACCUMULATION ON YOUR PERSON CAN ALSO BE A SOURCE OF IGNITION FOR PETROL AND ALL ALCOHOLS!!! INCIDENTALLY, ISOPROPYL ALCOHOL IS ALSO FLAMMABLE AND READILY FORMS VAPOURS AND COULD IGNITE UNDER SIMILAR CONDITIONS MENTIONED ABOVE when using this solvent!]
2. I would like to suggest you used way too much grease when greasing the focus ring components - which should only be applied very sparingly to parts of each surface requiring grease and then turning each surface to spread the grease across the respective surfaces - you should NOT apply grease to the entire surfaces in the manner you have. Using the excessive amount of grease in this manner will accelerate the formation of fungus over time [it is a staple food for these beasties] and will also seep out from the threads and eventually recontaminate the Iris diaphragm!
I hope my comments are of benefit to you and your followers - keep up the great work! Cheers from Down Under.
Very nice and interesting video, thanks for making this and especially for the running commentary! A possible suggestion when reassembling.... at some point along the way a technique I learned from someone, when re-attaching a part or an assembly using multiple screws, is not to fully tighten each screw at the start, but rather to put them in at almost full tightness but with a tiny amount of play, then to check the final alignment and fit, then to do that last 'full tighten' on all screws not in order around the barrel (1, 2, 3, 4) but in opposing pairs (1, 3, 2, then 4). In this way you may be more likely to get a better aligned fit, and of an even tightening so as not to distort the lens barrel, assembly, or other components.
thanks so much for this video! I just finished up my lens and I'm so excited I got it back together. Interesting these older Minoltas seem trickier to reassemble than some MD type lenses. you're such a huge help!
About to use this video this weekend! 🎉
Very good work, as usual! I'm delighted to see your videos!
Thank's Ramon :-)
Great job! Thank you , I could repair my PF58😀
Extremely helpful video, thank you so much for taking the time and effort to make it. cheers.
I'm happy it could help you :-)
Yes well after watching the video and then going through step by step, I was able to much improve my 58mm f1.4. I have another with the same problem so will hopefully have the same success. I did have a 28mm 3.5 MC W.ROKKOR-SG, which was also very stiff. I took it apart a few years ago, it took many attempts and approximately 3 years, to put it back together. That was because i did not make the marks on the lense barrels, as you quite rightly point out. Cheers
What an awesome review
Up date please on the #10 grease for the helicoil... Did it get runny and move into other area in a warm weather or home? your feed back would be appreciated by all..
Thank you for sharing your experience with us. Could you please tell me what kind of white grease you use here? Do you have any internet link or something to find it? Many thanks! Paolo
Usually it comes from Japan.
Muito bom ! Bem didático com excelente imagem. Parabéns !!!
Thank's :-)
Você merece ! Amigo por favor ! Tenho várias lentes não-AI de Nikon que gostaria de usar em minha D5300. Há algum inconveniente ou impedimento técnico. ?? ===== You deserve ! Friend, please ! I have several non-AI lenses from Nikon that I would like to use on my D5300. There is some inconvenience or technical impediment. ???
Need help with gold alignment pin placement in Canon 18-200 EFS lens. Followed all three of your disassembly vids and on part 3 the broken gold alignment pins you pull out, i cant remember how to re install those to continue with re assembly
Is it 100% necessary to clean the helicoid? Can I just wipe it down and add the new grease?
If you mean you do not want to dismantle the helicoid, then yes you can, use a toothpick or similar to get as much grease out as possible, then cotton buds & IPA. This method will not give the best results and you will not be able to clean the inner fine thread, but it is way less scary than disassembly of the helicoid. If you do fully dismantle, then it is best to remove all of the old grease with a solvent.
When removing the inner fine thread, rather than counting the number of turns until it comes apart, instead count how many full turns until it fully screws in. So if it is 1 and not another compete turn, for example, on reassembly, screw it all the way in, then out one complete turn, then carry on turning until the witness marks line up. It is a lot easier.
I have a Miranda 50mm f/1.8 similar to this minolta but the aperture ring is "locked" not moves, how I can resolve?
Is that lithium grease you use?
qual a expecificação dessa graxa, obrigado
Did you lose the ball bearing for the aperture ring? Without it, there's hardly any friction as you select the aperture. Hence, the clicking sound is missing. Just saying. The little ball bearing annoys me.
I got this lens very cheap, and at that time the little steele ball was missing, but if I want more friction on the aperture ring I can just use a tiny amount of Silicone grease on the inside of the aperture ring to make it more stiff.
hmmmm what does one do if they did not make a reference mark?
If you forgot to set a reference mark, it's actually possible to measure the total lenght of the lens, and in that way guess how should the helicoids sit.
@@mikeno62 Thanks for the reply mate. The lens in question was a Minolta AF 50mm 1.4...I managed to find a service manual and it turns out that the orientation of the helicoid threads does not matter. The manual provides mesuraments of the thickness of the assembled unit (to 0.1mm) at infinity. S you assemble the 'stack' and wind the helicoids until you get the exact measurement, and Bobs your uncle. Pleased to report it was a sterling success and I did not destroy the lens haha
Oh that's great Floyd :-), it's "just" to assemble the helicoid's and then adjust the focus ring to correct infinity, can I ask where you found the service manual for this lens, Thank's in advance.
Cheers
Kenneth