Reducer removal (help!)

[Trentend]

I swapped a 2” visual back on my C11 with a focal reducer last night when out in the cold and this morning I can’t for the life of me get the reducer off. It’s not crossed threads but feels locked solid. Any thoughts? Don’t want to take a hammer or blow touch to it…

[banjaxed]

You could try wearing a pair of gloves to give you a better grip.

[ONIKKINEN]

Try a strap wrench, or if you cant find one in a hardware store try an adjustable oil filter wrench (basically a strap wrench). I destroyed 2 small adapter extensions before getting one and now the problem seems to have gone away.

[Craney]

... or if you don't have any of the above, wrap some rubber bands around it for a bit more purchase.

Careful not to use too much force in gripping as you don't want to damage the circular integrity of the reducer, that the beauty of a strap wrench.

One adapter that had me beat in terms of mechanical force, freed itself up by being in the kitchen with the gentle warming and cooling of the room. Took a few days though !!

 

[ONIKKINEN]

And also thought i would mention if the thought crossed your mind: Keep pliers of any kind as far away from the adapter as possible, you WILL destroy it with pliers.

[RobertI]

I would definitely try gentle heat first - possibly wrap a dew strap round or someting similar, on full blast for an hour and then give it a go??

[Shimrod]

...and check the retaining ring inside the reducer is still tight once you've removed it from the scope otherwise you risk the lens elements falling out.

[Trentend]

Thanks all. I’ll perhaps let it defrost (it was very cold last night) and pick up a strap wrench from screwfix tomorrow to try. The reducer comes in two parts. The bit with the lens fortunately screwed out easily enough. What’s left is an extension adapter thing on the SCT thread. 

[david_taurus83]

You need to apply pressure onto the part and twist. This always works better for me than strap wrenches, rubber bands etc. Trainer with soft sole usually does the job. 

[Trentend]

Pressure as in downward towards the back of the C11 then turn?

[Trentend]

Sorted. Blasted with a hair dryer for a minute then put on some rubber gloves and managed to remove the reducer safe and sound.

[Jarno_c]

Although it's no longer needed here, mousepads can also work near miracles. Place it upside down (non-slip side up), hold it firmly in place, push the frozen part onto it with gentle pressure, and rotate. The mousepad provides so much friction that in many cases the part comes right off and more than once I've been able to remove stuck filters or extension rings this way. Alternatively you can wrap the mousepad around the part and see if that provides enough grip. I always have a mousepad in my astro goodies bag for just this purpose.

Jarno

[Andrew_B]

18 hours ago, Trentend said:

Thanks all. I’ll perhaps let it defrost (it was very cold last night) and pick up a strap wrench from screwfix tomorrow to try. The reducer comes in two parts. The bit with the lens fortunately screwed out easily enough. What’s left is an extension adapter thing on the SCT thread. 

Temperature is often the issue in cases like this. If the scope was cold and the reducer was warmer then the metal of the focuser tube will have contracted relative to the reducer. When you thread the reducer on, that small change in size can be enough to allow you to tighten it further than normal so when it cools down to the same temperature as the scope it contracts onto the focuser tube and the threads lock tight.

Differential heating can solve the problem and it sounds like you used that method when you blasted it with the hairdryer. The important thing in this situation is that you want to try and heat the reducer (or whatever else is screwed tight) while not heating the focuser tube - another method would be to use a hand warmer or microwaveable heating pad applied to the surface.