Restoring Helios 40 – 85mm f/1.5 – CLA tutorial by Tomas Glavina
Chapter I – Opening Helios 40 and disassembling focusing helicoid
01. Below is Helios 40 (after CLA)
02. This first step is very simple, grab the front (the nose) of the lens and the back, where the mount of the lens is as indicated by the arrows and turn CCW:
03. Unscrewing both parts, you will find that the lens is made of two main blocks – the front optical one and the rear focusing one. Set aside the big adjustment shim:
04. We will work on the focusing group first. Start by removing the tripod mount – remove two large screws. (Notice that everything except the focusing ring is made of brass:)
05. In the next step we will remove the external focusing ring. Unscrew three small screws indicated by the arrow and pull down the ring. You can screw them back a little to keep them in place. I suggest to do so if you are not going to polish the ring itself, just remember to untighten them a bit when putting the ring back!
06. Once separated, we are going to remove the inner focusing ring. To do so, unscrew the three screws indicated by the arrows, this time remove them completely and set them aside.
07. Take notice how deeply recessed the screws are, this is how they will have to be when putting them back in place.
08. Once the screws are removed we can proceed to untighten the black ring. Depending on the condition of the old grease, this can be very difficult at first. Clean the outside of the ring. You can check tips for cleaning here. Use rubber gloves, grab as much of the ring as you can with one hand, grab the back of the block near the mount with the other hand and turn CCW. In the extreme cases you can use a bit of WD40 or similar solution to soften the old grease. Spray a bit of it between the ring and the mount helicoid as indicated by the arrow and give it some time to penetrate. When you remove it, this is how it should look:
09. Lift up the brass part with the mount. To make it easier you can rotate (towards MFD) the bottom parts with the threads while holding the brass mount part above. Finally, two parts should fall apart.
10. We have to remove the screw (ratchet, teeth) that prevents the brass mount part from rotating. Before doing it, check if there is a mark left by the screw on the remaining ring. Big chances are that some sort of mark will be there but if it isn’t, make a small mark with a screwdriver. This is very important as it will help us to put back the ring in the proper position.
11. After making the mark, remove the screw.
12. Following step is critical for the whole process. You should proceed with caution in order to avoid headaches upon reassembling the focusing helicoid, since it has many steps on its thread and only one step (starting position) is correct.
Turn the focusing helicoid so that the bottom screw is at 6 o clock position and start to slowly turn the focusing ring CW. Apply light constant lifting pressure but not too strong. In the moment when the ring goes off the helicoid, stop rotating, take a look at the mark left by the screw (which you made in the previous step) and note its position within virtual clock scale. On my lens it happened at 3 o’clock. At this moment, push back the ring immediately, before you remove it and try to screw it back few turns. Repeat this action few times, until you get good idea, how it feels, when the ring enters the thread at the right place. You can turn the ring back all the way to check if the mark aligns with the hole for the screw. Be patient. If you do this well, you are out of most of the troubles.
13. We have now disassembled the focusing block and we can proceed to the cleaning.
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