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How to remove stuck extension ring?

accessories equipment astrophotography CMOS
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#1 NuTek


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Posted 17 October 2020 - 05:50 PM

How can I remove a 5mm extension ring that is stuck on my ZWO224MC camera?

I've tried using two rubber  strap wrenches, but the pieces are too small to grab a hold of and they just slip.

I tried putting the larger red part in a padded vise and turning the smaller black ring with a pair of channel pliers but 

the vise will not hold the ring securely without damaging it.  I also tried using pliers to turn the black ring (and red ring) 

and that just scratched things up.


Any ideas?


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#2 FiremanDan



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Posted 17 October 2020 - 05:51 PM

Something rubber!

try a tire inner tube or those big rubber bands for physical therapy and stretching.

Edited by FiremanDan, 17 October 2020 - 05:53 PM.

#3 Dynan



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Posted 17 October 2020 - 05:55 PM

Put it in the freezer for a few minutes.


EDIT: Then use your pliers...can't hurt it now.

Edited by Dynan, 17 October 2020 - 05:56 PM.

#4 Hank Banker

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Posted 17 October 2020 - 05:59 PM

I agree with Dynan. After you take it out of the freezer try heating only the red part.

#5 HansD



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Posted 17 October 2020 - 06:09 PM

I use a Jorgensen clamp for this. It's a wood clamp that doesn't mar the ring and will grip even a small ring. It gives you plenty of leverage.


#6 BeltofOrion


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Posted 17 October 2020 - 06:12 PM

If you haven't fixed it already, you might try something like this. Worked like a charm for me.


#7 Arcamigo


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Posted 17 October 2020 - 06:30 PM

Attach another ring to the black one to keep it cool while you heat the red part with a heat gun. If you don't have a heat gun, set it in a skillet over the stove with the red side down so the red part gets hot. Alternatively, if you can attach another ring to the black part, insert the black rings into ice water while you hold onto the red part to keep it warm.

#8 rms40


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Posted 17 October 2020 - 07:51 PM

I use the FiremanDan method. I have special barrel plug pliers, special rubber grips, and padded pliers. For some reason, a big rubber band always works when the others won't.


I read a thread about DSLR filters some time ago. It was recommended to always add a tiny bit of lubricant to filter threads. This was supposed to eliminate the frozen thread problem. Should work for adapter/spacer threads too. I haven't tried it but it makes sense. I am just too messy!



Edited by rms40, 17 October 2020 - 07:54 PM.

#9 Peregrinatum


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Posted 18 October 2020 - 08:55 AM

heat it up with a hair dryer around the circumference, then use rubber gloves

#10 WadeH237


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Posted 18 October 2020 - 09:28 AM

I had a thread adapter seize inside of one of my focal reducers.  The purpose of the adapter was to reduce the diameter of the reducer, so it fit completely inside of the reducer's threads.  Once it was stuck, it was impossible to reach it with any kind of tool to get leverage.


It stayed in that state for a few years, until one night my son and his wife were over at the house.  I handed it to him as a puzzle to figure out.  He went to the basement and came back with a racquetball.  I sat there in amazement as he jammed the racquetball into the adapter and proceeded to unscrew it from the reducer.  The texture and material of the racquetball gave a surprising amount of grip and provided a nice "knob" to turn it.

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#11 Dynan



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Posted 18 October 2020 - 09:37 AM

Field Expedience! Nice tip Wade!

#12 alphatripleplus


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Posted 18 October 2020 - 02:43 PM

Interesting suggestion. Please let us know if any of them help!

#13 Deesk06


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Posted 18 October 2020 - 03:12 PM

Thread another bigger adapter on it and then duct tape over the seam of the adapter you put on and the one you want to get it. Make a handle out of the duct tape as well so you can grab and pull it. That should work

#14 TxStars



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Posted 18 October 2020 - 04:06 PM

I forget the name of the wrench/tool but they are easy to make from fiberboard ..

You can make the I.D. slightly larger and place a rubber band around the part if more grip is needed.




Best thing is to brush threads clean with a toothbrush and only make finger tight.

Edited by TxStars, 18 October 2020 - 04:11 PM.

#15 fielderda


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Posted 18 October 2020 - 10:08 PM

I've had the same problems as you in the past and have scratched up a couple of adapters.

I now add a tiny amount of synthetic lubricant to the threads before threading them into a component, and haven't had any problems since.



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#16 mjgood


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Posted 18 October 2020 - 10:36 PM

Had the exact same issue couple days ago... as others said, you want the red part warm and the black cold.. try warming all of it, and it doesn't need to be very hot, then cool the black ring on some ice.. that's how I got mine apart..  finesse rather than force.. 

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