Iron ring on brass lens - possible to get off?

[GoodOldNorm]

Following this thread, it seems that some things are over looked.
1] Can you determine whether the white material is solder or something else?
2] Have you tried 'picking' at the material to see if it flakes out or fractures easily.
3] Can the lens be sufficiently identified, that Steven Tribe can tell what the iron ring covers?
4] If the iron ring sits on a knurled ring then the white material might have wept into the grooves of the knurling - hence worsening the removal problem.
5] The capability of the machinist/lathe to work to 1/1000th of an inch is not the issue. The issue is the ability of the machinist/lathe to finely adjust the incremental cutting/shaving depth.
6] Can the lens be dismantled [from both ends] so that there is less to be [possibly] damaged if and when the iron ring is removed.
7] Is there any indication that the bore of the iron ring is the same at both ends or is the thickness of the 'annulus' thinner where it is 'joined' to the lens.
I do not envy you.
Regards
Tony

I have worked with machinist at British Steel that would have made a whole new lens casing in exchange for a packet of cigarettes, on the night shift ;-). During WW2 a local lathe turner called "smoothie" sent a fine sewing needle he had drilled a small hole through at the pointed end to Mercedes in Germany. The needle was returned with 3 smaller holes through it decreasing in size ;-). Perhaps my judgement is clouded by memories of a time when we had the skills to be right up there with the best. There are still some very good machinist, most are retired spending their time building working scale models of steam engines or using their skills to make skeleton clocks. Most of these skilled workers started work at 14 years of age and worked at their craft until they retired at 65yrs of age.
In the UK we have lost the ability to "make do and mend".

[tonyowen]

[QUOTE=GoodOldNorm;1550974 Most of these skilled workers started work at 14 years of age and worked at their craft until they retired at 65yrs of age.
In the UK we have lost the ability to "make do and mend".[/QUOTE]

Based on your comments I'm a decade or so younger than you. But I started my apprenticeship at 15. In terms of skills, when I lived and worked in Canada [in the 1970s] we had a machinist who made small cups out of soft carbon for an airborne ore sampler, and another who could do marvels with a combined drilling-milling machine - both were European by origin. In the 1960s I worked at Universal Grinding Wheel Co and Rolls Royce. Both required ingenious engineering minds albeit they were opposites in terms of technology - one to worked in a grit laden environment, the other in clean room environment.

I do not agree with your last comment since there are always individuals that can go beyond what seems to be a barrier. But these individuals are not necessary British.

An interesting side issue, but not certain how it helps the OP

regards
Tony

[Havoc]

The problem is not working to exact standards, the problem is that you are effectively working blind. Like If the brass is not round because it had a bang before the iron ring went on. Or if it has ridges or if there are ribs on it.

I'm turning a piston for my steam engine this weekend but I wouldn't dream of trying to touch that iron ring. Not if you care for the brass beneath.

[tonyowen]

The problem is that you are effectively working blind. Like If the brass is not round because it had a bang before the iron ring went on. .

Exactly this is the purpose of my posting 20 to determine as much as possible about the situation BEFORE cutting and/or removing any metal/material.
I'm confident that the bore(s) of the iron ring are concentric with its outer diameter. If the lens body onto which the iron ring is attached has had a 'bang', then the bore of the iron ring would still be concentric with its outer diameter BUT there would be voids between the outer surface of the lenses' brass {???} body and the inner bore of the iron ring.

Go very very slowly with this investigation.

Regards
Tony

[Bernice Loui]

Following this thread, it seems that some things are over looked.
1] Can you determine whether the white material is solder or something else?

*Previously mentioned, how does one ascertain the joint is solder?

2] Have you tried 'picking' at the material to see if it flakes out or fractures easily.

*Not just picking at the material, apply the magnet and file test with the pick test.

3] Can the lens be sufficiently identified, that Steven Tribe can tell what the iron ring covers?

*Without digging in, this will not be so easy. Doing an X-ray image could help.

4] If the iron ring sits on a knurled ring then the white material might have wept into the grooves of the knurling - hence worsening the removal problem.

*Goes back to doing an X-ray image of the part to figure out what's inside.

5] The capability of the machinist/lathe to work to 1/1000th of an inch is not the issue. The issue is the ability of the machinist/lathe to finely adjust the incremental cutting/shaving depth.

*This is THE potentially lethal part, adjusting cutting depth is not an issue at all on any decent lathe, difficulty is setting this up in lathe that will render the part stable ... and... you're cutting into the unknown without something like a X-ray image to aid as a guide. The part is very likely not round which causes a completely different set of problems as the cutting nears the joint.

Setting up the part to run round in a lathe required either a four jaw chuck (preferred)
Attachment 203601

or a three jaw chuck that has the ability to be adjusted to the work's concentricity. Like this:


With the cutting tools and indicators required.
Attachment 203602

*Fact is cutting into the unknown is THE problem. This is why if the joint is ascertained to be solder, removal using a hot plate could be the best and least invasive method.



6] Can the lens be dismantled [from both ends] so that there is less to be [possibly] damaged if and when the iron ring is removed.

*Yes, taking the lens apart carries great risk that can further damage this lens.

7] Is there any indication that the bore of the iron ring is the same at both ends or is the thickness of the 'annulus' thinner where it is 'joined' to the lens.

*Another unknown that can add further complication in the attempt of removal.

I do not envy you. Regards Tony..


*These are some of the challenges and realities of trying to remove this ring. Alternative is to accept the lens as is and use it as is.


Bernice

[tonyowen]

I've had another look at the images of posting #1.

It looks as though the solder, if that is what it is, is tin or a solder with a high proportion of tin.
The problem is that [I quote] "Solders are different. Solders comprise dozens of alloy compositions, with melting points as low as 90° to as high as 400°C. ".

Thus if you can take a sample of the tin/solder or whatever it is, that is shown white on the surface of the iron ring. You can the test for melting/softening temperature and also identify what it might be.

Bernice's observations [above], with respect, merely reiterate my comments without adding to a solution. For instance #3 ignores the possibility of ID through what can be seen with or without dismantling. Also her references to x-ray assumes ready availability of such a service and expertise - which I assume would be costly if indeed available.

Regarding acceptance of the lens 'as is' I did not think this was a viable option by the OP.

Regards
Tony

[Roger Thoms]

I don’t think the iron ring was soldered on the lens. I think the iron ring was slightly loose so they applied solder to the inside of the ring to make it a pressfit on to the lens. Of course I could be wrong.

Roger

[Bernice Loui]

Indeed Tony, this task should NOT be taken lightly or causally. The very real problems involved are complex even if the goal appears simple.
This is why ascertain the joint's composition IS so Important before trying to do anything if you're wanting to remove that ring.

There is no easy quick-fix to this, only difficult and complex methods toward an attempt to remove that ring. All attempts have significant risk and to the parts involved and significant cost and demand on resources.


Bernice

I've had another look at the images of posting #1.

It looks as though the solder, if that is what it is, is tin or a solder with a high proportion of tin.
The problem is that [I quote] "Solders are different. Solders comprise dozens of alloy compositions, with melting points as low as 90° to as high as 400°C. ".

Thus if you can take a sample of the tin/solder or whatever it is, that is shown white on the surface of the iron ring. You can the test for melting/softening temperature and also identify what it might be.

Bernice's observations [above], with respect, merely reiterate my comments without adding to a solution. For instance #3 ignores the possibility of ID through what can be seen with or without dismantling. Also her references to x-ray assumes ready availability of such a service and expertise - which I assume would be costly if indeed available.

Regarding acceptance of the lens 'as is' I did not think this was a viable option by the OP.

Regards
Tony

[LabRat]

And then the "solution" of "sell the lens", but then said buyer shows up on LFF to enquire on how to remove "ring"...

Then the cycle repeats like a "Twilight Zone" re-run...

Try shooting this lens first to see what it does, or bury it so the archeologists can get grant funding to study this anomality...

Or leave it outside long enough until the ring rusts away... Are you gonna look at that thing or shoot it??? ;-)

Steve K

[Gary Beasley]

If it is pressfit simply getting the ring hot and putting ice to the brass inside would allow the ring to slip off.