Takumar 20mm 4.5 sticking focus

**Odinz** · 12-12-2015, 08:23 PM

I have a Takumar 20mm/F4.5 lens that looks fantastic and takes pretty decent photos. The only issue that I have is that on occasion the focus ring will suddenly become very stiff as if there is an obstruction on the helicoid, if you try it a few times it will eventually move past the "obstruction" but it will be very stiff. A few twists of the focus ring back and forth and it is smooth as ever and this may last for quite awhile before it "sticks" again. At first I thought that I needed to re-grease the helicoid, but in thinking more about it I'm thinking that it just might be a loose screw holding the focus ring to the helicoid, it wouldn't be the first time. I attempted to remove the front name ring (I have several different types of sets of friction tools for just such a task, but none seem to be able to loosen the name ring), it is stuck. Does anyone have any experience with this lens? Is there another way to gain access to the screws? Is there anything that can be done to safely "unstick" the name ring apart from drilling new holes for a set of spanners, or are there any screws I may to need to loosen first? I have a Takumar repair manual, but as we are renovating the floor of the house with my office/studio and it is boxed up somewhere and I can't find it at the moment.

Steve

Dartmoor Dave · 12-13-2015, 01:58 AM

It's been a couple of years since I last took my Super Takumar 20mm/4.5 apart, but it definitely had the usual type of Takumar construction. The name ring should unscrew in the usual way, so if it's too stuck for any kind of friction tool you might have to resort to drilling holes (much as I hate the idea).

Underneath the name ring there are three screws holding the front barrel/filter ring, and (if I remember correctly) three more for the focusing ring.

Your theory about a loose screw sounds very plausible, so hopefully it'll be a fairly straightforward fix.

**Odinz** · 12-13-2015, 07:25 AM

Originally posted by dcshooter

....There are a handful of lenses where the front barrel and name ring are all one piece, and the barrel screws in and is held in place by tiny set screws at its base (revealed by bringing the lens to its minimum focus distance)......

dcshooter - Thanks, I was hoping that this would be a lens with the screws, I have encountered those on other lenses, but it doesn't appear to be the case here, it looks like I'll have to keep working at the ring or maybe send it in to be 'silvered'

Originally posted by Dartmoor Dave

.....The name ring should unscrew in the usual way, so if it's too stuck for any kind of friction tool you might have to resort to drilling holes.....

Dartmoor Dave - Thanks, I have never taken this particular lens apart before, but I thought the screws would be a quick fix. But as with most things its the easiest jobs that seem to take the longest. Now that I know that it is just typical Takumar construction I'll just have to keep working at it (I hate having to drill those holes.....)

**Odinz** · 12-17-2015, 06:51 PM

dcshooter, thanks for the hair dryer trick, didn't even have to resort to the MEK. Once I got the name ring off and the barrel shroud out the problem was clear, as best as I can describe there was a sticky substance about half way down the shroud that ran along about 50% of the circumference of the barrel that was the consistency of thick dried soda. Once that was cleaned out and I tightened the focus ring screws just a touch the lens focuses like butter.

Thanks again.
Steve

**hjoseph7** · 12-17-2015, 10:59 PM

I had a problem like that with my Takumar 50mm f1.4. I'm not sure if its the same problem as yours or if they are related. I was thinking about sending the lens back to the seller not because the lens would stick on occasion, but because he described it as being in excellent condition. In any case, for a couple of days I began turning the focusing ring on that lens back and forth. I made a full turn to the right and a full turn to the left. I must have repeated this about 200+ times. Next thing I know the lens focusing ring was turning smoothly and not sticking. I haven't had any problems since then with it either. I'm thinking the lens was sitting for a while and the grease might have become less fluid ?

**Odinz** · 12-18-2015, 12:19 PM

I have had that happen with several older 3rd party lenses before. They sit on a shelf or in a bag unused for years and the grease breaks down, stiffens up, oil starts flowing to places it shouldn't etc. Most times I end up having to re-grease them, but have on one or two occasions had them start working just fine again after a little use.

12-12-2015, 08:23 PM	#1
Odinz Loyal Site Supporter Join Date: Jan 2008 Location: Virginia, USA Photos: Albums Posts: 259	Takumar 20mm 4.5 sticking focus I have a Takumar 20mm/F4.5 lens that looks fantastic and takes pretty decent photos. The only issue that I have is that on occasion the focus ring will suddenly become very stiff as if there is an obstruction on the helicoid, if you try it a few times it will eventually move past the "obstruction" but it will be very stiff. A few twists of the focus ring back and forth and it is smooth as ever and this may last for quite awhile before it "sticks" again. At first I thought that I needed to re-grease the helicoid, but in thinking more about it I'm thinking that it just might be a loose screw holding the focus ring to the helicoid, it wouldn't be the first time. I attempted to remove the front name ring (I have several different types of sets of friction tools for just such a task, but none seem to be able to loosen the name ring), it is stuck. Does anyone have any experience with this lens? Is there another way to gain access to the screws? Is there anything that can be done to safely "unstick" the name ring apart from drilling new holes for a set of spanners, or are there any screws I may to need to loosen first? I have a Takumar repair manual, but as we are renovating the floor of the house with my office/studio and it is boxed up somewhere and I can't find it at the moment. Steve

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12-13-2015, 01:58 AM	#2
Dartmoor Dave Pentaxian Join Date: Aug 2012 Location: Dartmoor, UK Photos: Gallery Posts: 3,890	It's been a couple of years since I last took my Super Takumar 20mm/4.5 apart, but it definitely had the usual type of Takumar construction. The name ring should unscrew in the usual way, so if it's too stuck for any kind of friction tool you might have to resort to drilling holes (much as I hate the idea). Underneath the name ring there are three screws holding the front barrel/filter ring, and (if I remember correctly) three more for the focusing ring. Your theory about a loose screw sounds very plausible, so hopefully it'll be a fairly straightforward fix.

12-13-2015, 07:25 AM	#3
Odinz Loyal Site Supporter Join Date: Jan 2008 Location: Virginia, USA Photos: Albums Posts: 259 Original Poster	Originally posted by dcshooter ....There are a handful of lenses where the front barrel and name ring are all one piece, and the barrel screws in and is held in place by tiny set screws at its base (revealed by bringing the lens to its minimum focus distance)...... dcshooter - Thanks, I was hoping that this would be a lens with the screws, I have encountered those on other lenses, but it doesn't appear to be the case here, it looks like I'll have to keep working at the ring or maybe send it in to be 'silvered' Originally posted by Dartmoor Dave .....The name ring should unscrew in the usual way, so if it's too stuck for any kind of friction tool you might have to resort to drilling holes..... Dartmoor Dave - Thanks, I have never taken this particular lens apart before, but I thought the screws would be a quick fix. But as with most things its the easiest jobs that seem to take the longest. Now that I know that it is just typical Takumar construction I'll just have to keep working at it (I hate having to drill those holes.....)

12-17-2015, 06:51 PM	#4
Odinz Loyal Site Supporter Join Date: Jan 2008 Location: Virginia, USA Photos: Albums Posts: 259 Original Poster	dcshooter, thanks for the hair dryer trick, didn't even have to resort to the MEK. Once I got the name ring off and the barrel shroud out the problem was clear, as best as I can describe there was a sticky substance about half way down the shroud that ran along about 50% of the circumference of the barrel that was the consistency of thick dried soda. Once that was cleaned out and I tightened the focus ring screws just a touch the lens focuses like butter. Thanks again. Steve

12-17-2015, 10:59 PM	#5
hjoseph7 Site Supporter Join Date: May 2014 Location: Minnesota Photos: Gallery \| Albums Posts: 2,048	I had a problem like that with my Takumar 50mm f1.4. I'm not sure if its the same problem as yours or if they are related. I was thinking about sending the lens back to the seller not because the lens would stick on occasion, but because he described it as being in excellent condition. In any case, for a couple of days I began turning the focusing ring on that lens back and forth. I made a full turn to the right and a full turn to the left. I must have repeated this about 200+ times. Next thing I know the lens focusing ring was turning smoothly and not sticking. I haven't had any problems since then with it either. I'm thinking the lens was sitting for a while and the grease might have become less fluid ?

12-18-2015, 12:19 PM	#6
Odinz Loyal Site Supporter Join Date: Jan 2008 Location: Virginia, USA Photos: Albums Posts: 259 Original Poster	I have had that happen with several older 3rd party lenses before. They sit on a shelf or in a bag unused for years and the grease breaks down, stiffens up, oil starts flowing to places it shouldn't etc. Most times I end up having to re-grease them, but have on one or two occasions had them start working just fine again after a little use.