Restoring Helios 40 – 85mm f/1.5 – CLA tutorial by Tomas Glavina

by viktor pavlovic · Published December 3, 2017 · Updated December 3, 2017

Chapter IV – Helios 40 – re-assembling focusing block

24. First, be sure that you lubricated threads.

25. Remember that critical task in the step 12? Well, now you will see if you did that part well, or you’ll have to buy some pills for the headache and prepare for unlimited number of trials and errors…
Align the bottom screw to 6 o clock position (as we had it upon removal), put the first focusing ring on top and align the mark to 3 o’clock position. Move it slightly back and forth to find the step on the helicoid, it may take some time to do it, proceed slowly with lot of patience and before you apply any power, be sure that it entered the thread step correctly. Once it has grabbed the thread, turn it CCW.

26.Keep turning the ring until the mark reaches the hole for the screw. If you manage to align the mark end the hole, you got the correct step on the thread, if not, try to remember (or take a pic) of how much it’s off the correct position. Turn back the ring any try a step before the one you got, (if you passed the hole) or the next one (if you didn’t reach it). In any case, if they still don’t align, repeat the procedure until you get it right.

27. Put back the little screw. Use some force making attention not to ruin its head because it must stay firmly in place. Grease the »slot« as seen below. Don’t put too much grease on this part, it is where most of the resistance of the focusing comes from but make sure you put enough, as the optical block of this lens is heavy. Incorrect amount of the grease can be felt when holding the lens horizontally.

28. Next, we have to put back the brass part with the mount. To grease the internal slot you can use some of the old, stiff greases.

29. Align the slot with the head of the screw and slip it gently over. It’s much easier to do it with the top focusing ring set to MFD.

30. Once it’s in place, we have to grease the upper part indicated by the arrow, but there is no need to grease the thread itself.

The next few steps could be more complicated since we have to top the first focusing ring with the second one. It has to fit into a precise position at the end, so you can’t just tighten it randomly. The recessions for the three screws must align with the small holes below. The problem is the recessions get covered by the ring as you tighten it, at least for my eyes it’s difficult to see the recessions thru the small holes.

31. Mark the position of one of the recessions on the mount part with a sharpie and make sure the first focusing ring is at its MFD position.

32. Put back the second focusing ring. There is only one step so no guessing this time but make sure the inner side and it’s thread are free of any dirt. On the picture below, you can see the position when my ring stopped to go further without resistance.

33. We must now align the holes with the recessions, so keep tightening, but don’t use too much force or you can damage the head of that important screw.

In the picture above it looks like the mark and the hole aren’t aligned due to the angle at which I took the picture. Aligning them can be tricky because turning the ring in the opposite direction, in case you past the marking, will turn the focusing toward infinity while the ring itself will stay in place. In this case, keep turning it until it reaches infinity so you can untighten the second focusing ring a bit. Once you get them into position put back the three screws.

Notice how deeply the screws must set

34. Next turn the focusing ring to infinity, you can now test the resistance of the focusing. Keep in mind that with the outer focusing ring in place, it will be a bit easier to turn it (it has a larger radius).