[niceshot]

Recently I was using this lens and the Helical came apart on me. So I had to rebuild it without any guide or witness marks and this proved to be difficult but I did it after a few failed attempts at achieving Infinity focus. I finally got it right so I want to explain how I achieved this so if some one else gets this problem they can fix it. I didn't take any photos so this will only be useful if you have experience.
1 remove the name plate 2 remove 4 screws and 2 retainers and remove the optical block, it will fall into your hand put it out of the way.3 remove the rubber grip on the focus grip, slide it off. 4 loosen the 4 grub screws but don't remove them 5 slide it off and put it on the side 6 you will see 4 screw on the barrel remove them, the hold the secondary helical in place. now turn out the secondary helical all the way and the guides will fall out put them together with the 4 screws 7 If the primary helical came out not to worry , you can clean it and then reengage it and once you get it down far enough you need to get the aperture guide to engage and the helical guides at the same .A flashlight will help. If you get this done your are half way there. 8 Here is the most important step to achieving infinity focus , so pay attention . First turn the primary helical until it almost disengages from the aperture lever. Put it down for now 9 you need to put the secondary helical guides back onto the barrel ,10 NOW here comes the tricky part .you need to engage the secondary helical 180 degrees from when the helical guides will engage but when you come around you will need to turn the primary helical out to create room and once you engage turn the primary helical all the way in. if you did all of this correctly there will be very little space between the barrel the the helical .If that is the case then you are in business. 11 drop back in the optical block by aligning the notch with the longer of the two guides set your aperture to 2.5 and rotate the block to get proper adjustment put the retainers on and go check it for infinity if you got it stop and go throw back on you focus grip at the infinity spot and tighten you grub screws .and lastly you name play good luck to all BEST WISHIES ... PS DO IT AT YOUW OUW RISK/ ALSO if you have a had time to mesh the helical walk away and breath.

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Last edited by niceshot; 01-16-2022 at 08:03 PM.

[pepperberry farm]

Recently I was using this lens and the Helical came apart on me. So I had to rebuild it without any guide or witness marks and this proved to be difficult but I did it after a few failed attempts at achieving Infinity focus. I finally got it right so I want to explain how I achieved this so if some one else gets this problem they can fix it. I didn't take any photos so this will only be useful if you have experience.

1 remove the name plate

2 remove 4 screws and 2 retainers and remove the optical block, it will fall into your hand put it out of the way.

3 remove the rubber grip on the focus grip, slide it off.

4 loosen the 4 grub screws but don't remove them

5 slide it off and put it on the side

6 you will see 4 screw on the barrel remove them, the hold the secondary helical in place. now turn out the secondary helical all the way and the guides will fall out put them together with the 4 screws

7 If the primary helical came out not to worry , you can clean it and then reengage it and once you get it down far enough you need to get the aperture guide to engage and the helical guides at the same .A flashlight will help. If you get this done your are half way there.

8 Here is the most important step to achieving infinity focus , so pay attention . First turn the primary helical until it almost disengages from the aperture lever. Put it down for now

9 you need to put the secondary helical guides back onto the barrel

10 NOW here comes the tricky part .you need to engage the secondary helical 180 degrees from when the helical guides will engage but when you come around you will need to turn the primary helical out to create room and once you engage turn the primary helical all the way in. if you did all of this correctly there will be very little space between the barrel the the helical .If that is the case then you are in business.

11 drop back in the optical block by aligning the notch with the longer of the two guides set your aperture to 2.5 and rotate the block to get proper adjustment put the retainers on and go check it for infinity
if you got it stop and go throw back on you focus grip at the infinity spot and tighten you grub screws .and lastly you name play good luck to all

BEST WISHIES ... PS DO IT AT YOUW OUW RISK/
ALSO if you have a had time to mesh the helical walk away and breath.

just to make it easier to read through... but some photos or even a video would help...

[niceshot]

just to make it easier to read through... but some photos or even a video would help...

thanks for the edit, yes when I was in the middle of it I didn't take any pictures as it took a lot of try's to synchronize the 2 helical . They have to work together to achieve infinity focus. . I STILL think it should help someone it a similar predicament.

[stevebrot]

just to make it easier to read through... but some photos or even a video would help...

Replacement of "helical" with "helicoid" might also be in order.


Steve

(...always the pedant... )

[pepperberry farm]

Steve

(...always the pedant... )

I'd expect nothing less....

(: