Can you identify these custom Leica R 80mm fronts? Best way to get them off?

[Roman Alaivi]

I've been aching to get into the Anamorphic world for some time now and recently got a Kowa 16H to pair up with my Leica Rs. Problem is, the fronts on these R's I purchased as a set are a very permanent modification. The rings are glued to the exterior / around the circumference of the lens rather than being a threaded step up ring. It's a very well made / heavy duty mod that feels native to the lens itself. Because of the size of these fronts, I need to be able to take them off in order to clamp on the Kowa 16H properly.

I'm not sure if any of you Leica R fans might be able to identify who would do a custom job like this? The regulars like Duclos, Cine Mod and other guys just make regular threaded step-up fronts but this is a very custom job. I got the set off eBay from a RED user / shooter but I've been unable to get in contact with them again. Any help or advice for a good lens tech I could reach out to would be much appreciated.

https://photos.app.goo.gl/hC91YMh1aqzNaI3z2

https://photos.app.goo.gl/4rXXSpTp6Q5b1DnF3

 

[Eric Lange]

I've been aching to get into the Anamorphic world for some time now and recently got a Kowa 16H to pair up with my Leica Rs. Problem is, the fronts on these R's I purchased as a set are a very permanent modification. The rings are glued to the exterior / around the circumference of the lens rather than being a threaded step up ring. It's a very well made / heavy duty mod that feels native to the lens itself. Because of the size of these fronts, I need to be able to take them off in order to clamp on the Kowa 16H properly.

I'm not sure if any of you Leica R fans might be able to identify who would do a custom job like this? The regulars like Duclos, Cine Mod and other guys just make regular threaded step-up fronts but this is a very custom job. I got the set off eBay from a RED user / shooter but I've been unable to get in contact with them again. Any help or advice for a good lens tech I could reach out to would be much appreciated.

https://photos.app.goo.gl/hC91YMh1aqzNaI3z2

https://photos.app.goo.gl/4rXXSpTp6Q5b1DnF3

Wasn't me lol !

What is the material of the front ring ?

And do you have any sense of what adhesive might have been used ? Are there any adhesive leaks that might show … (if you hit it with a black light/ UV source you can see certain adhesives fluoresce more easily). That way 'We" can carry out solubility tests.

As a former conservator and materials scientist I might be able to devise a way to get those off without harming your lens.

\__________________________________

Leica R was the first camera I ever used as an 8 year old... My brother's , but he would always taken my crappy OM10 on archeological excavations (for months at a time in foreign countries) with him with the "excuse" his camera was too heavy to have around his neck all the time (The weight of all that mazing glass he didn't want stolen... ). I saved up for two years to buy that OM10 yet my grandmother bought him the LEICA R.... (older brother).

 

[Nick Gardner]

Are those delrin? Could be press fit delrin rings. Hit them with a hair dryer, see if they get any wiggle in them. If they are too hot to touch for more than 10 seconds, they are too hot ;-)

Nick

 

[Eric Lange]

Are those delrin? Could be press fit delrin rings. Hit them with a hair dryer, see if they get any wiggle in them. If they are too hot to touch for more than 10 seconds, they are too hot ;-)

Nick

+1

That's what I was wondering too … [especially if they used a thermo-setting resin as well].

But thought the opposite maybe stick it in the freezer in a sealed big sealed box of desiccant / silica gel for 48 hours maybe the adhesive crystalizes and you can crack the part off...


If they used epoxy that will be a b*tch.. Nylon/ Derlin not easy to adhere to … So as you say could be press fit. If the part is fit to OD then aluminum bronze or 6061 should contract to smaller diameter than the Derlin and if the part is press fit ID then the Derlin might get crushed (in a good way) from compressive shrinkage from aluminum bronze crushing inwards on the Derlin (at a faster rate)… (At lower temperatures / differential thermal contraction/ expansion of the two materials having different coefficients for thermal expansion and if an adhesive was used will also have a different CoTE. *).

[I'm sure if OP drops it on the floor just right he might get lucky ;-)/lol].


I was wondering also maybe OP takes it to reasonably skilled prototype machine shop and maybe they can set it in a vice jaws/ soft jaws cut to the right diameter OR maybe the Duclos guys have sense of what forces you can apply to the fitting without trashing the lens... Worst case scenario you can carefully machine the fitting off... But need to machine blanks etc. to protect the lens.

Would be funny if someone used a left handed thread on that so it won't come off ;-)


"Why won't it come off?? "


"Cuz you're f*ck'n tightening it!... Left handed thread... ".

_____________________________________________________________________________________________________________________________

* https://www.engineeringtoolbox.com/linear-expansion-coefficients-d_95.html

 

[Eric Lange]

Wondering if there is way to use a gear puller without trashing the lens ?

 

[Roman Alaivi]

Wasn't me lol !

What is the material of the front ring ?

And do you have any sense of what adhesive might have been used ? Are there any adhesive leaks that might show … (if you hit it with a black light/ UV source you can see certain adhesives fluoresce more easily). That way 'We" can carry out solubility tests.

As a former conservator and materials scientist I might be able to devise a way to get those off without harming your lens.

\__________________________________

Leica R was the first camera I ever used as an 8 year old... My brother's , but he would always taken my crappy OM10 on archeological excavations (for months at a time in foreign countries) with him with the "excuse" his camera was too heavy to have around his neck all the time (The weight of all that mazing glass he didn't want stolen... ). I saved up for two years to buy that OM10 yet my grandmother bought him the LEICA R.... (older brother).

Thanks Eric!

I believe the ring is just metal, I'm not sure I can get more specific than that haha. I wish I knew my materials better however I can definitely confirm that it's not Derlin, this is just a regular weighty metal ring that feels nothing like what Derlin feels like.

I really have no idea what adhesive might have been used here, I suppose I could try out that UV / Black light and take a picture, not sure what I would need to be looking for there though.

 

[Roman Alaivi]

I was wondering also maybe OP takes it to reasonably skilled prototype machine shop and maybe they can set it in a vice jaws/ soft jaws cut to the right diameter OR maybe the Duclos guys have sense of what forces you can apply to the fitting without trashing the lens... Worst case scenario you can carefully machine the fitting off... But need to machine blanks etc. to protect the lens.

Yeah, I suppose this is ultimately what needs to be done. I could visit a machine shop of some kind to pop it off via vice jaws.. just seems scary, don't want to damage the lens housing in any way (Leica R's aren't the most resilient bodies but I'm hoping they'd put up with getting man handled a bit here. The camera repair place / lens tech near where I live didn't want to attempt anything like that so I suppose I just need to brave it.

 

[Roman Alaivi]

Are those delrin? Could be press fit delrin rings. Hit them with a hair dryer, see if they get any wiggle in them. If they are too hot to touch for more than 10 seconds, they are too hot ;-)

Nick

Definitely aren't Derlin, I don't think heat would work in this case. If anything, cooling the metal down to the point where it might contract sufficiently to pop it off might be an option though..

 

[Eric Lange]

Thanks Eric!

I believe the ring is just metal, I'm not sure I can get more specific than that haha. I wish I knew my materials better however I can definitely confirm that it's not Derlin, this is just a regular weighty metal ring that feels nothing like what Derlin feels like.

I really have no idea what adhesive might have been used here, I suppose I could try out that UV / Black light and take a picture, not sure what I would need to be looking for there though.

In that case looks like some kind of aluminum Alloy like 6061 and anodized. I can understand why Nick G would think it's made of Derlin as the surface finishes on that part are not the greatest (chatter + almost galling) + it seems 5X thiker than it needs to be.

It's an interesting one to do by remote control... From a distance. I feel like saying where do live FEDEX it I'll get it off and fedex it back.

_______________________________________________________________________________________________________________________


With The UV light means you can find residues of the adhesive (possibly). If that the case one can possibly identify what type of adhesive has been used and hence devise which types of solvents or solvent blend might free the ring. (Carrying out solubility tests on a small area to see what most readily shifts the adhesive).

Typically epoxies (unless the are very high grade) tend to be quite viscous so you might see bead of epoxy or even an epoxy that is filled with lamp black pigment.

Seems odd to me that someone would devise such a fitting that is NON-REVERSABLE (and requires one to trash the lens to remove that component)…

I wonder if there is not a small hidden set screw or some weird threading.

Other possibility they used Cyano-acrylate... (For expediency) and that is bit more reversible mechanically and chemically. The UV light will be useful to possibly detect cyano-acrylates.

Typically you have to be very careful using swabs made from rolling cotton wool onto cocktail sticks to introduce solvent into various seams that get drawn in by capillary action.

Some of the solvent go-to's are high grade acetone (laboratory grade or just stuff that smells nice rather than rough... the rough stuff has toluene (nasty)). Methanol also Tri-cholo-ethane... Some of the next level solvents would be Hexane (if the used a rubber cement based compound), then naphthalene and Toulene and even MEK (Methyl Ethyl Ketone)… Then there are the gelled solvents that are like serious industrial strength paint stripper (you don't want to go there).

The trick is you have create a bung or barrier or stopper to prevent solvent vapors from condensing in the surface of your lens especially if you re-activate . solubilize some of the cyanoacrylate...

Require patience skill and the courage of your convictions to apply more force than what you might want.


I'm still wondering if there might be a screw/threaded fitting; in that past lens fittings I have made for various projects front ring attachments that only used only one and half threads on the ring and was not tight nor loose, so if someone wanted to make it more permanent then they might have used Locktight / industrial cyanoacrylate or compounds used to help fix bearings in place for good "Interference fit".


@Roman have you got any more photos to look at of this assembly / close ups ? [I'm trying to find the original lens so I can understand what they did.. ] The external surface finish is not that great so seems doubtful they would have devised a "Shrink fit" i.e. close tolerance ring heat up then placed onto the camera assembly that is then "Shrunk" fit (past tense of shrink fit?) onto the lens barrel/body. But if dome right that bond can be very very strong indeed. [No adhesive required.].

________________________________________________________________________________________

[Will edit as it seems I can't speak or write English this morning lol ! ].

Kowa 16H sounds interesting

If you are really bored you can take the whole lens apart from the back going forward …

There are a number of YouTube videos that show you how to do that for your lens perhaps https://www.youtube.com/watch?time_continue=16&v=Wepbwbq4oMg

I love how low tech the "Production values" are on this …^^^

This one is not bad just good general technique... https://www.youtube.com/watch?v=v5vyLYe863k

https://www.youtube.com/watch?time_continue=4&v=Pap4DtsGJAU

(Older lens). This guy "Fix old cameras" has a ton of stuff... I just discovered how to fix my stuck/jammed shutter on an Mamiya RB 67 I have lol... See that's good ! And also a repair he does on Hasselblad shutter mechanism reminds why pro-photographers like their Kowas back in the day as they were less "neurotic/ finicky" than the Hasselblad's.

 

[Roman Alaivi]

Well I think this says it all... I am a very silly person.
https://photos.app.goo.gl/fkZD4FgiIpPvzP812

The rings were fastened so tightly, I've never quite encountered a step up that could get on that tight and not have cracked the lens threading or housing. The only way it came off actually was because I had connected my clamp for the anamorphic lens to the ring and just cranked it.

 

[Eric Lange]

Well I think this says it all... I am a very silly person.
https://photos.app.goo.gl/fkZD4FgiIpPvzP812

The rings were fastened so tightly, I've never quite encountered a step up that could get on that tight and not have cracked the lens threading or housing. The only way it came off actually was because I had connected my clamp for the anamorphic lens to the ring and just cranked it.

YAY!... Looks like its has that 1 1/2 tiny threads on there like I used to make for front ring attachments also.

Looks like that would be easy to cross thread... or bind when torqued too far. Happens to the best of us at least those that are careful... And those that are good at breaking sh*t probably would have removed that ring without thinking lol.


[Had you fedexed it I had a jig set up and a long handled clamping fixture to apply torque progressively to just try to unscrew it (as a tests first), but there is not a lot of space to grab hold of there below that ring it seems so WELL DONE ! … ].

 

[Roman Alaivi]

Thanks Eric! Glad I got it off without anything breaking hah :001_smile:

I'm definitely glad it didn't cross thread there, would have been easy for sure.