FS 60 knurled knob stuck

[graham.hobart]

Hello, on my FS 60 there is a knurled knob which allows for rotation of the diagonal and also a knurled knob with a plastic washer inside it which grips the eye piece barrel. For some reason the bit that allows for rotation of the diagonal has jammed into the smaller black knurled piece- so I can only swing my eye piece one way currently.
Now I don't want to ruin it with pliers or mole grips- so does anyone have any idea how I can loosen this without too much pressure which will deform the ring?

see pic with arrow..
Graz

[casstony]

Different metals expand or contract at different rates with temperature changes - you could try warming it in direct sunlight for 15 minutes then see if it will come apart, or alternatively put it in the fridge to cool and try again.

[graham.hobart]

Ahh , I forgot about the old bimetal strip stuff! Thanks for reminding me - part is in fridge as we speak cooling down. Should have waited for the Wife to come home as that is what she does with the jam jars!
Graham.

[bartman]

+1

[graham.hobart]

still stuck - any other advice?:question:

[brian nordstrom]

:shrug: a 1 inch wide strip of leather ( an old belt ) and a pair of vice grips .
Wrap the leather around the seized bit and have the 2 ends together , then grip both ends of the leather with the vice grips ( in a straight line wiht the ends of the leather belt ) and slowley try to undo , this is like an oil filter remover on a car engine and it will apply lots of torque without any damage . :question: worth a try . with the heat and cold options already mentioned it might get it off .
Brian.

[adman]

I always found the trick to those was remembering which way you had to turn it to tighten/loosen them. More often than not I would want to loosen it, but end up tightening it.

I have no suggestions how to get it out though - the hot/cold might be the best option, but make sure you are trying to turn it the right way!

Adam

[bojan]

A drop of WD40 may help.. Don't spay!

[Omaroo]

I've had this issue before too, and I've used strong string or twine. You take a couple of two foot lengths of twine, fold each of them in two and wind them around each of the knurled sections in the appropriate directions. Held tightly, wind the end of one around fingers on one hand and the other, well.. the other. It's easy to untwist them with this aid as the knurling diamond pattern is quite bitey.

[graham.hobart]

two rubber strip wrenches from Mitre 10 did the job, plus some judicious lube- I found out that the inner barrel of the diagonal had unscrewed and lodged itself into the tightening bit!
Cheers for all your advice chaps
:D