Best way to loosen eyepiece glue

[dtrinh]

Hi everyone,
I have an eyepiece that need to be cleaned, but I can't loosen the screw; the glue seems to be too strong (yet, there are big dust particles inside).
Does anyone know what is the best option here?
Thanks!

[Scarodactyl]

I don't think these are glued shut. Maybe whoever opened it last overtorqued it.
I'm curious, any particular reason you'reusing the 4x? It seems an unfortunate magnification for most modern camera sensors.

[Phill Brown]

Some Nikon parts are just done up very tight on assembly.
I've had plenty JIS screws that feel like they are definitely going to break but just let go with a crack.
There's no reason to glue a service part so logic says that just needs the right tools.

[PeteM]

First, make sure you have a good quality pin spanner. Cheap ones will torque out of the pins. A good one might apply 2x the torque with ease. Hold the fixed end of the relay lens with soft jaw connector pliers or even better in a vise with wooden "jaws" made by drilling a hole in wood ever so slightly smaller and then cutting the hole in halves. Lathe collets are even better as a non-marking vise grip but most folks won't have access to them.

Heat (tiny hot air gun) to expand the outer part will usually do the trick. If not, a drop or two of a thread solvent such as Kroil left to soak and with heat applied.

[Phill Brown]

Visions of putting in a vice and wind it up till it pops apart.
If you can see the dust is inside that's one thing,if it only shows up on the camera it could be damage to the outer lens coating also.

[dtrinh]

I don't think these are glued shut. Maybe whoever opened it last overtorqued it.
I'm curious, any particular reason you'reusing the 4x? It seems an unfortunate magnification for most modern camera sensors.

Hi,
thank you for the reply. Yes, it is a second hand, and the first owner tried to open it without success (he stated so).
I tested it with an APS-C camera, and the magnification is slightly bigger than the Bresser 2x adapter (I don't know why). Only the very center part is projected on the sensor, but I don't mind much when I observe water microbes. At 20x for example, Paramecium would be as long as half of the sensor; lower magnification would make them much smaller.
The 4x relay will be a disadvantage when I observe cross sections of plant stems for example, but it is much cheaper and easier to find than other lens
Bests,

[dtrinh]

Thanks everyone for your comments, I will try and report the result.
Bests,

[dtrinh]

Hi again everyone,
So I heated up the lens with a hair dryer, and I was able to disassemble it. Now I have a clean lens producing clear images.
Thank you all!
Best regards,

[Scarodactyl]

Glad to hear it! There's nothing as frustrating as a dirty projective eyepiece.
If you ever pick up a 2.5x I'd suggest avoiding the pl 2.5x, go for the 2.5xa or the pli 2.5x (the 23mm one not the 30mm).