Reinstalling lens retaining ring

[MartinTenbones]

I'm having trouble getting a retaining ring to seat back down on the lens. It's a old Meyer-Optic Görlitz Domiplan

It will thread in however it won't seat down tight enough to stop the glass from rattling around.

I'm wondering if I can apply some gentle heat to it and try to seat it that way.

Any other tricks to help?

Thanks

 

[Andreas Thaler]

I'm having trouble getting a retaining ring to seat back down on the lens. It's a old Meyer-Optic Görlitz Domiplan

It will thread in however it won't seat down tight enough to stop the glass from rattling around.

I'm wondering if I can apply some gentle heat to it and try to seat it that way.

Any other tricks to help?

Thanks

You could apply a tiny amount of oil or WD-40 etc. to the threads of the ring and this may help to screw it in completely.

Be careful not to tilt it as this may cause the ring to get stuck on its way.

 

[BrianShaw]

Before all else, scrupulously clean the threads on both parts. If still necessary, I’d opt for a tiny bit of moly or silicone grease, or a tiny bit of liquid dry lube (basically Teflon).

 

[MartinTenbones]

OK I'll try this. I think I'll also take the bottom half back out of the lens. I'm thinking it's possible with that part threaded in to the lens already may be pushing the internal thread in enough to make it tight.

I'll see how it goes

 

[MartinTenbones]

OK so here it is. I have a feeling there may be a burr in one or more of the channels cut for the lens wrench. It threads in by hand up until the point in the picture then things get tight. Maybe a bit of sanding or filing would help.

Then a bit of touch up!

 

[Dan Daniel]

It could be the slots and the removal tool distorting threads, as you say. You can run a knife tip or such along the threads and possibly remove any burrs. Often such threads are standard. So a screw's threads will match the retaining ring thread. Meaning that '.5' threading is .5 threading, on a 1.6mm screw and on a 30mm retaining ring. I mention this in case you don't have a thread gauge. I've used a thread gauge that matches as a 'scraper' to help restore threads. Or at least as a feeler gauge that can show where the threads have gone bad. Then a 60 degree file can be used to clean up that area.

 

[JPD]

I agree with Dan, and can only add the wisdom to be careful and don't  Rush it.

 

[MartinTenbones]

Thanks Dan,

I will pick up one of these gauges. It looks very useful indeed.

Now I will need to look for information on how to attempt to realign the rear element. In my attempt tp get to the rear of the blades I fell into the trap of removing the 3 set screws I now know never to touch.

When I put the lens on my Fuji T1 the images are very soft. I know this could ne the infinity focus as well but I do know that removing the rear element the way I did causes all sorts of headaches.

Being pretty new to all this I will as this question. With focus assist on the digital set to infinity I get strong indicators that buildings far off are in focus. Is that an accurate way of checking infinity focus on a lens?

I will start searching for my next solution and if need be starting another thread might be best.

 

[paul ron]

when you took it appart, was it tight? if it was and now it isnt, something went wrong. maybe there is dirt in the threads or the lens is missing a spacer or an element is put in upside down. the spanner may have bruised the notches and thats hanging it up?

take the glass out and try figuring out whats going on.

as for aligning it... a collimeter is the best tool but you can do some rough adjustment by using a ground glass on the film plane while focusing to infinity.