Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

How to separate two spacers that are stuck together? Tips please before I go mental!

  • Please log in to reply
19 replies to this topic

#1 SimonIRE

SimonIRE

    Mariner 2

  • -----
  • topic starter
  • Posts: 200
  • Joined: 16 Dec 2018
  • Loc: South East England

Posted 14 February 2020 - 02:47 AM

Hi All, 

 

Quick question; have any of you got some nifty tips for separating spacers that get stuck in the field?

 

Last night I had an imaging session ruined because the exact spacers I needed seemed almost welded together in the cold. I tried to brute force it without success - destroyed my hands in the process. 

 

I have tried heating them, using washing up liquid and rubber gloves and today I ordered a rubber strap wrench. As ridiculous as it sounds, if the wrench doesn't work I am going to have to buy new ones. 

 

Many thanks for any ideas....

 

Simon



#2 Sleep Deprived

Sleep Deprived

    Mariner 2

  • *****
  • Posts: 225
  • Joined: 17 Apr 2019
  • Loc: Seattle Area

Posted 14 February 2020 - 03:08 AM

Before you apply too much force to them (probably already too late, based on your description) try holding one wall of each between thumb and forefinger and try unscrewing them.  When you grab around the whole thing, you may be bending them.

 

If you really want a project, set the inner one on ice, and set something warm on/around the outer one.

 

I've not had this problem, but I work in a machine shop - we use liquid nitrogen by the gallon, and heaters, getting things apart all the time.  In the shop, a sharp rap with a hammer sometimes helps by setting up a vibration - don't know that I'd do that with something as delicate as spacers.

 

Good luck! (That's probably the most useful thing I've done here.)


  • Jon Isaacs, Dynan and NuclearRoy like this

#3 RaulTheRat

RaulTheRat

    Viking 1

  • -----
  • Posts: 676
  • Joined: 09 Oct 2018

Posted 14 February 2020 - 03:18 AM

Now that they are together I guess I don't have any more to offer as help, but I generally screw stuff together with a thin delrin spacer between if I'm concerned that they might get stuck and that seems to help prevent it.

#4 happylimpet

happylimpet

    Skylab

  • *****
  • Posts: 4,355
  • Joined: 29 Sep 2013
  • Loc: Southampton, UK

Posted 14 February 2020 - 03:23 AM

13015b.jpg  and 

 

s-l1600.jpg

 

has always worked for me. but not without some scuffing.



#5 Garthid

Garthid

    Explorer 1

  • *****
  • Posts: 63
  • Joined: 23 Jul 2016

Posted 14 February 2020 - 04:37 AM

What I've found that works so far is a DIY strap wrench. USB cords work well to make a hoop that you can pinch tightly around spacer A, and then do the same with spacer B. Turn each in opposite directions. The more "grippy" the cord the better.  Hope it works for you.


  • Delta608, happylimpet and Dynan like this

#6 pyrasanth

pyrasanth

    Vanguard

  • *****
  • Posts: 2,372
  • Joined: 08 Jan 2016

Posted 14 February 2020 - 04:38 AM

Rings that stick together have been a bane of my life. There are a few tricks you can try. Sometimes if you sandwich the rings between the soles of a rubber shoe & twist that can work well. If that does not work heat the rings repeatedly with a hair dryer on hot & dunking in cold water- then back to the rubber soled shoes.

 

Often the cause of the rings locking is micro welding or galling- its interesting- look it up on the wiki. I now use anti seize grease. I use the aluminium type- can be a bit messy but no more stuck rings and adapters. The delrin shims also work okay but remember they will change the length of the connection so that needs taking into account for critical spacing. 

 

One last thing- always use even pressure around the ring. If the pressure is not even you risk bending or distorting the ring which will make it even harder to remove- don't ever use a vice.


Edited by pyrasanth, 14 February 2020 - 06:13 AM.

  • happylimpet likes this

#7 Dynan

Dynan

    Soyuz

  • *****
  • Posts: 3,615
  • Joined: 11 Mar 2018
  • Loc: NOLA

Posted 14 February 2020 - 05:24 AM

Try two of these, opposing each other:

 

https://www.amazon.c...81675782&sr=8-9



#8 John Tucker

John Tucker

    Apollo

  • *****
  • Posts: 1,076
  • Joined: 03 Mar 2018

Posted 14 February 2020 - 06:37 AM

I place the stuck spacers on a rubber mat, rubber glove, or other non-scratching, high friction surface, and press down/twist with my foot while wearing a rubber sole shoe.  

 

Works well for the short extenders that it is hard to get a wrench around. 

 

Generally I put a little wax or oil on the threads, carefully removing any excess, before first use of any extension tube. 


  • Dynan and OldManSky like this

#9 Jon Isaacs

Jon Isaacs

    ISS

  • *****
  • Posts: 81,943
  • Joined: 16 Jun 2004
  • Loc: San Diego and Boulevard, CA

Posted 14 February 2020 - 07:05 AM

Lots of techniques mentioned, heat and cold, vibration. You want to cool the male side so it shrinks. 

 

In extreme cases, I make my own clamp wrenches. Each wrench is two pieces of wood, a long one for the handle, a short one for the clamp. I bolt the clamp to the handle with a thin shim between them. I drill a hole the diameter of the stuck part at the joint between them. 

 

I make two of these and then clamp one to each side. The bolts provide a lot of clamping force but it the walls are thin, too much force can deform the adapters. 

 

Jon



#10 TOMDEY

TOMDEY

    Fly Me to the Moon

  • *****
  • Posts: 5,738
  • Joined: 10 Feb 2014
  • Loc: Springwater, NY

Posted 14 February 2020 - 07:10 AM

That's a universal problem without a universal solution. Which is to say, all of the above anecdotes, suggestions, and potential solutions are welcome. But, the frustrating part is each case is different and there are no guaranteed non-destructive solutions whatsoever.

 

Which is a place we don't like to be, especially situations where failure will result to dead in the water. If you luck out and tease them apart today, no guarantee that they won't be hopelessly frozen tight tomorrow at 3am, on a perfect night, at your dark site, two hours from home.

 

Threaded fasteners are ill-conceived right out of the blocks. Convenient and simple-minded... but conceptually-flawed. Consider this: You screw them together to precisely attach the two parts via the matching male/female threads. You have to get it tight enough to hold, yet loose enough to not hopelessly jam, gall or damage. Too loose and it might fall apart, too tight and it might weld forever. So, you are entirely relying on guesstimated friction... That could be a cheap bottle cap or a $20K camera, still held on by nothing more than "hand-tight". And, as noted above... temperature, humidity, atmosphere, pressure, even just time... can hopelessly loosen of tighten.

 

Some fancy rotate-on fasteners comprise mechanical "phase-change" mechanisms to overcome the above problems. Many camera lenses have the bayonet that clicks when engaged and locked. And release with e.g. a little push-button. I recall, with some exasperation, that the Zuiko and Nikon lenses had opposite directions. And one failure mode of the Zuiko was that the release button would fail stuck on. Only way off was a sledge hammer. The picture below is ... I think it's a Nikon lens. Even the best brands sport ultra-cheesy mechanical fasteners.    Tom

Attached Thumbnails

  • 151 lens bayonette failure stuck on.jpg

  • MikeMiller likes this

#11 SimonIRE

SimonIRE

    Mariner 2

  • -----
  • topic starter
  • Posts: 200
  • Joined: 16 Dec 2018
  • Loc: South East England

Posted 14 February 2020 - 07:31 AM

Still no luck with all these suggestions (which I appreciate....) - wrenches not arrived yet so I am holding out for a miracle....

 

Thanks all - will keep you updated. 



#12 Simcal

Simcal

    Mariner 2

  • *****
  • Posts: 217
  • Joined: 01 Oct 2018
  • Loc: Caledon, Ontario

Posted 14 February 2020 - 09:19 AM

heat, lots of heat, on the female side.  hold them against a stovetop ring if you have to, or put them in the oven..  if there is rust or corrosion involved, then use a penetrating oil..  but then be careful of open flame of course..



#13 Xeroid

Xeroid

    Surveyor 1

  • *****
  • Posts: 1,599
  • Joined: 21 Sep 2013
  • Loc: USA

Posted 14 February 2020 - 09:49 AM

If you can find this in the EU or Amazon UK this WILL WORK:

 

Blaster 16-PB Penetrating Catalyst



#14 AhBok

AhBok

    Mercury-Atlas

  • *****
  • Posts: 2,531
  • Joined: 02 Dec 2010
  • Loc: Lakeland, TN

Posted 14 February 2020 - 11:18 AM

I used to use my strap wrenches, but I found a solution that never fails me. I tighten a zip tie on each piece in opposite directions. Then I take two small pliers and pull on the ends of the ties in a way that tightens the ties around the spacers as I pull them apart. It is difficult to describe, but easy to do if you follow my crude description.


  • Simcal likes this

#15 SimonIRE

SimonIRE

    Mariner 2

  • -----
  • topic starter
  • Posts: 200
  • Joined: 16 Dec 2018
  • Loc: South East England

Posted 14 February 2020 - 11:30 AM

Unfortunately the rubber strap wrenches arrived and no luck. PB blaster isn’t quickly available in the UK....

Buying new spacers is look more and more like the only option...arghhhhhh

Edited by SimonIRE, 14 February 2020 - 11:30 AM.


#16 SimonIRE

SimonIRE

    Mariner 2

  • -----
  • topic starter
  • Posts: 200
  • Joined: 16 Dec 2018
  • Loc: South East England

Posted 14 February 2020 - 11:36 AM

heat, lots of heat, on the female side. hold them against a stovetop ring if you have to, or put them in the oven.. if there is rust or corrosion involved, then use a penetrating oil.. but then be careful of open flame of course..


Unbelievable.

I just stuck the thing on my gas cooker for 1 minute and when it came off it was hot but I was still to handle it; it just came apart like butter

Weird.....the wonderful world of physics....
  • John O'Grady, kevint1, Simcal and 2 others like this

#17 TOMDEY

TOMDEY

    Fly Me to the Moon

  • *****
  • Posts: 5,738
  • Joined: 10 Feb 2014
  • Loc: Springwater, NY

Posted 14 February 2020 - 12:05 PM

Figured out why this thread caught my attention.

 

Larger Context: This comes under the umbrella of "Fasteners" --- where mechanical parts are (supposed to) electively mate/separate seamlessly, reliably, easily, safely... with minimum investment in time, tools, effort or finesse. And the directions for threaded rotary fasteners sure sounds like the ultimate in simplicity. e.g. Directions: Rotate the parts together until snug; reverse to separate. Do not overtighten. I always like that parting nebulous caution, pre-blaming the customer for when it gets stuck. What could possibly go wrong?!

 

Anyway, decades ago, I got involved in what might just be the ultimate worry-ball regrading fastening two objects together... satellite docking! It's a full seven-degree of freedom task (roll, pitch, yaw, x, y, z, time). Timely, high-stakes, difficult, risky, huge list of potential failure modes. I got a couple of patents on the related tools, #5054929, #5069528.

 

On the other hand, when I can't get the lid off a pickle jar... I hand it to my wife. She does something mysterious involving the kitchen sink and a butter knife, and it's open.    Tom

Attached Thumbnails

  • 153 toms citation satellite docking.jpg


#18 Simcal

Simcal

    Mariner 2

  • *****
  • Posts: 217
  • Joined: 01 Oct 2018
  • Loc: Caledon, Ontario

Posted 14 February 2020 - 12:08 PM

Unbelievable.

I just stuck the thing on my gas cooker for 1 minute and when it came off it was hot but I was still to handle it; it just came apart like butter

Weird.....the wonderful world of physics....

Thanks go to my long-passed Lancashire born tool & die making Dad for that one. At least I learned something from him LOL! waytogo.gif



#19 Dynan

Dynan

    Soyuz

  • *****
  • Posts: 3,615
  • Joined: 11 Mar 2018
  • Loc: NOLA

Posted 15 February 2020 - 04:03 PM

Another method is to warm the set slightly....not warmer than you can handle barehanded. Then use a can of compressed air UPSIDE DOWN (where it yields 'liquid air') and very carefully aimed the inner piece, possibly with an included narrow straw. The temperature differential could do the trick.



#20 Fernando134

Fernando134

    Ranger 4

  • -----
  • Posts: 356
  • Joined: 02 Feb 2013
  • Loc: Brasil

Posted 15 February 2020 - 04:25 PM

Hi All, 

 

Quick question; have any of you got some nifty tips for separating spacers that get stuck in the field?

 

Last night I had an imaging session ruined because the exact spacers I needed seemed almost welded together in the cold. I tried to brute force it without success - destroyed my hands in the process. 

 

I have tried heating them, using washing up liquid and rubber gloves and today I ordered a rubber strap wrench. As ridiculous as it sounds, if the wrench doesn't work I am going to have to buy new ones. 

 

Many thanks for any ideas....

 

Simon

I can not give you a "perfect solution", but only my previous experience. I had my cannon ring stuck to my field flattner. A nightmare. What I did was to spray WD40 between the things. Wait a couple of minutes. And then...with my hands! I was expecting to have to use some tools, but was unecessary. Maybe I was lucky, though.




CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics