Adapter stuck to reducer

[pmlogg]

Another stuck adapter topic I'm afraid.

I am making changes to my set up and need to remove an M82 to M48 adapter from my Riccardi 0.75x reducer.  Unfortunately it is stuck solid!  The photo shows the adapter in question attached to the reducer.  It is quite thin which is part of the problem - virtually no edge at the M82 side of the adapter and the M48 side thread is quite far from the stuck M82 threads so pressure there is not directly opposite.

There are a lot of good suggestions that I've read, and I've tried a number of them.  Included in the list are using training shoes, using rubber mats, rubber gloves. putting WD40 in the joint and repeated sequential cooling and freezing.  With the reducer being an expensive piece of kit I've not heated beyond room temperature.  No success with any attempt yet.

I have had one other thought and that was to superglue a sacrificial M48 extension to the M48 thread, put the M48 side into a padded vice and seek to rotate the reducer by rubber-gloved hand.  Afterwards hopefully I might be able to salvage the M82 to M48 adapter by use of a commercially available superglue debonder or acetone.

Any comments or suggestions would be very welcome.  And yes, I have noted that I need to use boot polish or similar before using any more adapters.

 

[Elp]

Heat with a hairdryer or electric heater should get it off (don't use a heat gun) with little issue as I often do it with my m42 spacers. But, be cautious with it, try to funnel the heat toward the adaptor only and point the source away from the reducer body (you don't want to heat the reducer anyway), try wrapping it with something to deflect some heat. I'd be more cautious if there was glass directly behind the adaptor.

Try your suggestion first, screw something onto it which can be secure then turn.

Edited July 13, 2023 by Elp

[globular]

You could put two vertical notches in the adapter thread - directly opposite each other. You could then insert a metal ruler or similar spanning the two slots and sticking out further beyond the adapter too.  The extra traction should see it come free.  The notches should not prevent the adapter from being reused - if cut cleanly.

[ONIKKINEN]

11 minutes ago, pmlogg said:

I have had one other thought and that was to superglue a sacrificial M48 extension to the M48 thread, put the M48 side into a padded vice and seek to rotate the reducer by rubber-gloved hand.  Afterwards hopefully I might be able to salvage the M82 to M48 adapter by use of a commercially available superglue debonder or acetone.

 

I did something like this to remove a very thin adapter, not unlike the issue you have here.

What i did was thread a sacrificial extender to the available thread and then squeeze that tightly to the inner thread using guide scope rings as makeshift 3-point pliers. I first destroyed the nylon tips of course so that there is a good bite. The 3 adjustment screws can then bite into the sacrificial extender and so prevent the sacfificial extender from unthreading out of the inner threads. The sacrificial item is completely mangled now but i got the original problem solved.

[vlaiv]

Can you make a diagram of threads?

I've found that extension rings and adapters have certain flex in them and depending on pressure that you put on them - you can either increase or decrease friction in threads.

For example - with extension rings - you can unscrew one side if you use another extension ring that you screw in to the other side. Sounds funny - but it actually works.

putting pressure on one side - on male thread for example with another extension ring (red arrows) will cause other side to expand outward (blue arrows) thus reducing friction on female thread.

If your thin adapter is like this:

meaning it has male threads on both sides, then, using force by pushing it towards the reducer will have negative effect:

What you want to try is to attach another M48 extension tube and then "pull" on it as you unscrew the whole assembly - instead applying pressure towards the reducer (as you would instinctively).

[Paz]

40 minutes ago, globular said:

You could put two vertical notches in the adapter thread - directly opposite each other. You could then insert a metal ruler or similar spanning the two slots and sticking out further beyond the adapter too.  The extra traction should see it come free.  The notches should not prevent the adapter from being reused - if cut cleanly.

I've done something similar to this to separate some stuck t2 adapters. If you are squeamish read no further...!

I filed a number of notches around the perimeter of one side that was otherwise smooth and impossible to grip.

On top of that I wrapped a thick rubber band around it and got an adjustable spanner on to it. 

All of this put together did the trick.

[Stuart1971]

I normally push the offending side down very hard on a good rubber mat and turn with a flat palm, works every time…👍🏻

[pmlogg]

Thank you so much for the response and for the suggestions.   

For Vlaiv, here's an image of the adapter.  It is as you drew, male on both sides. When in use just the 2mm wide edge is visible. I have had one try pulling on another adapter but so far no success. 

For Stuart1971, I had already tried that several times with, different rubber mats but had no joy with it.

I will let you know how I get on - I will try the least destructive first, not least to protect the glass from damage, including from metal filings. 

[The60mmKid]

Depending on your location, this may or may not be relevant: Scopestuff (in the US) sells a set of delrin adapter wrenches. They are absolute lifesavers. Before I bought them, I spent hours battling with adapters.

Scopestuff does ship internationally, but that would take time.

[The60mmKid]

2 minutes ago, The60mmKid said:

Depending on your location, this may or may not be relevant: Scopestuff (in the US) sells a set of delrin adapter wrenches. They are absolute lifesavers. Before I bought them, I spent hours battling with adapters.

Scopestuff does ship internationally, but that would take time.

Here's a link: http://scopestuff.com/ss_fwrn.htm

[AstroKeith]

As per Stuart above. I have always released these by putting one piece on a silicone mat, and pressing down on the top piece with another silicone mat with the palm of the hand, push quite hard, and twist.

This is doing two things. Obviously you must not grip or hold the reducer body around its side. Its thin and any grip will squeeze the threads,

Secondly the downward force tends to push apart the locked thread profile.

A good way of warming up the reducer is a) a dew heater strap, b) friction, grip it with a garden glove or similar and give it a good few rotations back and forth. This can get the heat right to the thread end. c) Put an ice pack on the top. -18C ice in a plastic bag will soon cool it down.

But 95% of the time the downward palm trick works for me. - No holding the side remember!

Edited July 14, 2023 by AstroKeith

[JeremyS]

I recently had a colour filter stuck on a 2-inch EP. I followed a YouTube video which advised putting a rubber band on the filter to provide grip. Then use index finger and thumb of one hand to grip as much of the circumference of the filter as possible. Worked a treat.

[900SL]

I use rubber gloves, been able to free every stuck spacer / adapter to date

[Stefan73]

I've always found a strap wrench invaluable astronomy kit for this sort of thing.  For example:

https://cpc.farnell.com/duratool/d00070/strap-wrench-set-2pc/dp/TL10279

[PeterC65]

I use the temperature gradient method. I put the whole thing in the freezer for 30 minutes then dip the end that needs expanding into a saucer of boiling water.

In your case you need to contract the adapter which makes things more tricky. You would need to heat the whole thing and then dip the adapter in cold water. I would be inclined to put the whole assembly into a very low oven (50 degrees) then place it onto a open container filled to the brim with iced water so that the flat of the adapter rested on the rim of the container.

The wrenches mentioned by @The60mmKid sound really useful. I've recently bought a pair of Knipex 8701250 water pump pliers which can be fitted with plastic jaws to fulfil a similar purpose.

 

[Priesters]

1 hour ago, Stefan73 said:

I've always found a strap wrench invaluable astronomy kit for this sort of thing

Plus 1 for this.  It sorted a stuck 2mm extension tube so not a dissimilar problem to yours. Also, my wife found them incredibly useful for opening jars so for the first time ever I got brownie points for buying Astro related gear.

Edited July 14, 2023 by Priesters

[Richard_]

15 hours ago, pmlogg said:

Another stuck adapter topic I'm afraid.

I am making changes to my set up and need to remove an M82 to M48 adapter from my Riccardi 0.75x reducer.  Unfortunately it is stuck solid!  The photo shows the adapter in question attached to the reducer.  It is quite thin which is part of the problem - virtually no edge at the M82 side of the adapter and the M48 side thread is quite far from the stuck M82 threads so pressure there is not directly opposite.

There are a lot of good suggestions that I've read, and I've tried a number of them.  Included in the list are using training shoes, using rubber mats, rubber gloves. putting WD40 in the joint and repeated sequential cooling and freezing.  With the reducer being an expensive piece of kit I've not heated beyond room temperature.  No success with any attempt yet.

I have had one other thought and that was to superglue a sacrificial M48 extension to the M48 thread, put the M48 side into a padded vice and seek to rotate the reducer by rubber-gloved hand.  Afterwards hopefully I might be able to salvage the M82 to M48 adapter by use of a commercially available superglue debonder or acetone.

Any comments or suggestions would be very welcome.  And yes, I have noted that I need to use boot polish or similar before using any more adapters.

 

When you say rubber gloves, do you mean like  nitrile gloves? 

I've found that coated rubber gloves with a textured surface have worked well in removing stuck on M48 adapters. However, my adapters had a little more length and purchase than yours, so maybe thatthe gloves won't be  enough. Below are the gloves in question. 

https://www.amazon.co.uk/gp/aw/d/B07SX2P1MK?psc=1&ref=ppx_pop_mob_b_asin_title

[pmlogg]

Hi Richard

They weren't those gloves but two different types of kitchen rubber gloves, also heat retardant gloves that have a type of rubber insert.  Also used different types of rubber squares on top and below.  I think the purchase is a big part of the problem, also that the M82 threads are quite deep/long as it the image I posted.

It's likely that the WD40 didn't manage to get all the way down.  Even though I used quite a bit, the gaps for it to enter are very small.  And of course I don't want to get oil, water or debris onto the lens surface.

Stefan

Yes, a strap wrench, which I have, could help with the reducer, using one of the other suggestions for the M48 side.

Has anyone got experience of debonding superglue? As I mentioned in my first post?

Thanks again all.

[900SL]

Heat slowly in oven to 120C or so. This will soften superglue. I did this to remove a adapter that some plonker had superglued on

Obviously don't do this if the components are fragile or may be damaged in any way by heat. And handle with thick gloves

 

WD40 isn't that good as a thread release. 50/50 acetone/ATF is much better but again don't use where it could damage optics etc. Volatile compounds evaporate over time and can deposit eslewhere

Edited July 15, 2023 by 900SL

[vlaiv]

7 minutes ago, pmlogg said:

Has anyone got experience of debonding superglue? As I mentioned in my first post?

Not much, but I've seen that some variants of superglue are not very tolerant to heat.

I had 3d printed case that housed banana pi single board computer that got really hot - like 60+ C for prolonged periods of time. Interestingly, pla that case was printed with - fared quite ok, but super glue that was used to put the case together started behaving strangely - I could find that whitish superglue residue all over the case - as if it had evaporated and condensed on other parts of the case.

I did some research and appears that some CA variants don't tolerate heat (or rather you need high temperature one to resist heat above 80C).

Maybe that can ease debonding?

Another thing that is useful idea is to try it first with some scrap aluminum or unused bits (old extension rings) - apply super glue and then see what debonding method works the best?

[Ouroboros]

Is the M48 protruding side sticking out sufficiently to put in a vice and rotate the reducer? 

[Ouroboros]

To use temperature you’d need to cool the adapter to make it contract. Could you place the adapter end in iced water? Then have another go with rubber mat/gloves? 

Edited July 15, 2023 by Ouroboros

[pmlogg]

Vlaiv, I like the ideal of testing the debonding first.  And I still have to have a go at some other options - family visits and prep for them have delayed my attempts.

Ouroboros,  Not much thread for a vice to get hold of; that's part of the reason for my thought of trying to use a sacrificial M48 adapter.  Again, for a similar reason not much to stick into water (and I'm rather adverse to having water near the reducer) but perhaps with an M48 extension it could be dipped in to suck heat from the adapter. 

 

[Ouroboros]

8 hours ago, pmlogg said:

Vlaiv, I like the ideal of testing the debonding first.  And I still have to have a go at some other options - family visits and prep for them have delayed my attempts.

Ouroboros,  Not much thread for a vice to get hold of; that's part of the reason for my thought of trying to use a sacrificial M48 adapter.  Again, for a similar reason not much to stick into water (and I'm rather adverse to having water near the reducer) but perhaps with an M48 extension it could be dipped in to suck heat from the adapter. 

 

Yes, I’d feel the same. How about placing the adapter side down onto a layer of ice?  You could place a layer of aluminium foil between the ice and the adapter to conduct heat and protect the reducer. 

[windjammer]

My vote is for the slots - 1mm wide and about 1-2mm deep as suggested.  See pic.  Simple hacksaw is all you need, just make sure the blade cuts a slot wide enough for the ruler or flat steel piece you use as the spanner.  Stuff tissue paper into the hole to stop metal swarf going inside, and have a vacuum cleaner handy to suck any stuff out.  If it really is recalcitrant, put the ruler or steel piece into a vice with only 1-2 mm protruding, locate the article on top, lean into it and twist.

My standard procedure now is to cut slots into every adapter, extension ring etc that comes along, just for this situation!

Simon