I want to be able (after destroying 2 lovely lenses trying) to open, remove parts, clean them ultrasonically, and re-assemble them and have them still work.
I have machinist’s ink (prussian blue, of course) which seems to show promise on the ultrasonic side, but: This needs to go on dark parts and still be easily visible. Prussian blue is a nice color, but tends to disappear when painted on charcoal-to-black parts.
I’ve run various felt-tips - I can get good contrast right up until it goes into the ultrasonic cleaner.
I can use a machinist’s scribe and scratch into the parts (internal), but, aside from being tacky and unprofessional, it introduces a possible source of flare if in the optical path. We don’t need more pics of “ghosts” that weren’t visible until you saw the pics.
You might want to give somewhat more detailed description of what exactly you are trying to do and what role you expect the ink to play in this process. I have only the sketchiest notion via your description of what you are trying to accomplish.
Permanent markers come in a variety of colors including metallic (silver etc) high contrast colors that would stand out on dark metal and should survive an ultrasonic cleaning with no issues. Using isopropyl alcohol they should wipe cleanly off a polished metallic surface after the ultrasonic cleaning is finished.
Is this so that parts can be marked with their assembly order, then cleaned in the same ultrasound bath? If so, it’s probably better just to put each part in its own little basket (which can be tagged) than to actually mark them, isn’t it?
8th pic shows the idea (of course, he is not using ultrasound - that is my touch to avoid dealing with 7 tiny blades held by gravity alone (you do NOT want to try this at home, kids).
The idea is to avoid spending 5-10K buying the proper equipment to get all the pieces aligned. This method simply assumes the factory got it right, so, as long as you can precisely duplicate what the factory did, you’re good.
I want to find a way to lift the entire assembly out intact, run it through the ultrasound, and put it back.
Photographers (search boost) - any idea why it matters how the iris is oriented? As long as the blafes are fully open when the actuator tab is at 12:00 and fully closed when at 9:00, what matters.
For those with a mechanical bent: notice how the iris sits in the lens - that is a solid chunk of metal machined into a cup shape. the bottom cannot be removed, and that bit of glass immediately below the iris cannot be touched by anything hard or sharp. Fully open, the hole is about 1/2" dia. The entiire assembly is 1 1/4" dia.Clearance to the glass below is 3/8"
Know any tool which could be inserted into the 1/2" hole and then have it’s head expand to an inch or or so without touching the lower glass?
So far I’ve come up with a pipe cleaner formed into tweezers with the last 3/8" bent outward. Whit the the two ends held together, it can be inserted and is strong enough to lift the iris, but it’s unstable.
Ideas?
No, have not tried correction fluid, but will.
Clear nail polish tends to run all over the place and glue everything together. This helps keep the pieces in place during re-assembly, bt i snot really workable.
Might mention - the reason for the ultrasound in the first place is an incredibly thin oil (makes 3-it-1 look like transmission fluid) which gets on the iris blades and jams them.
Repair shops charge 60-150 to clean them. Unfortunately, I am not the only person who’s found Pete’s pages and is stocking up on specialty tools,
Any ideas for an easily removable sealing wax?
Thanks for the replies
Correction fluid will show up very well on dark parts. Not sure if it’ll contaminate your parts though. If you have an ultrasonic cleaner that can remove correction fluid, what model is it? I’m pretty sure mine won’t remove ink of any form.
What do you want the sealing wax to seal? Around the lens? I’m thinking of Parafilm.
Interesting, usually a Sharpie on metal is pretty tenacious. It usually takes some rubbing with alcohol to get the permanent marker off metal. What is the solution you are using consist of? If it’s alcohol or solvent based you can forget about permanent markers and almost any other most ink based marker making it through the bath.
Well, that’s the second problem - after the bath, it gets a quick dip in alcohol (rubbing) to displace the water and speed drying (the coating’s sensitive). I’ve found that double-sided tape will with stand both the ultrasound and alcohol, but the force required to remove it pretty well insures it falls apart.
In the case of one of the 2 lenses, it is easy to remove all glass and be left with the iris still lock in place. At first, I skipped the iris removal/re-install (and 2 hour’s work for me) by just cleaning it in place. Then I found the clear plastic over the focus distance scale had hazed - I seem to have traced it to the change from rubbing to isopropyl alcohol.
Back to cleaning it in place for the models which use that design. Luckily, the expensive one coming in uses the same design.
Which puts us back to marking - I’m tending toward maybe sticking on something that can be marked - if the tape can be loosened by the alcohol,
Isopropyl is “rubbing alcohol”. the main difference is that it’s usually a 70%/30% alcohol water blend vs 90-100% purity for straight industrial isopropyl.
This probably doesn’t help, but might be worth investigating if you can’t find anything else.
noodlersink.com makes a range of specialty inks, including some that are purportedly impossible to remove from paper. They’re made primarily for fountain pens, but you could apply it with a brush or dip pen. It’s possible they have something that will survive on metal.
If you’re thinking of sticking tapes, I really like Brother’s TZ laminated labels. They stick very well and can be removed quite cleanly. I think they use an acrylic based adhesive.
Well -
Experimental results:
White-Out - good ultrasound resistance, doesn’t run - may use it for exterior marks.
Sharpie now makes an ink-based marker - it is essentially paint, but holds up to ultrasound very well.
Trouble with both of these is their thickness - if applied to the side of the lens barrel, they protrude into the space the iris needs to rise above.
I’m now re-thinking the whole “mark the top to get the bottom where you want it” theory.
The iris is actuated by a post on the bottom - visible in the link above. That is what the camera moves to open/close the aperture - the critical pat is getting the same size opening with the actuator in the same position - if a 1/4" hole is obtained by moving the actuator 27 degrees above point x on the mount, then it should still give you a 1/4" opening AFTER you’re done.
Since the silly thing falls apart when you try to remove it, I don’t see how you can be certain where the tab was relative to the mark you put on the top.
I’m thinking of using a gauge (7/16 " dowel) and closing the aperture down onto it, then marking the position of the tab - on the outside, where it doesn’t get in the way.
During re-assembly, insert the iris and put a stack of steel washers on it to keep the pieces together. Insert dowel, move rod until it aligns with mark.