Olympus BH-2 head opening

[Milou]

I've tried to open this trinocular head, removing the 4 screws on its bottom

After that, I could with a hairdryer warm the light pass selector item which was completely blocked !

I also wanted to remove the bottom optic hold with 3 screws (see picture), but in fact 3 others screws inside are also holding this one (see upper part of first picture)

Therefore some questions about this head:

- What kind of grease could I use for dovetails of the light pass selector item, in order to be more easily moved?
- can I remove the 3 screws inside (see first picture) holding the bottom part, as they seem to be glued, or better to avoid it?

P1110458.resized.JPG (81.09 KiB) Viewed 1907 times

P1110459.resized.JPG (76.89 KiB) Viewed 1907 times

Thank you for your help

[deBult]

Looks like a CH2 head to me?

Maintenance guides and videos (BH2) by our forum member Carl H. (give a flavor on what to do) and a CH maintenance guide
in writing on

https://www.alanwood.net/olympus/downloads.html#bh2

Plastilube break grease will do, clean the rails with lighter fluid first.

The “glued” screws are glued so the alignment of the optics stays in place, suggest to keep them in position.

The screw heads may look like Philips but are actually JIS (Japanese Industry Standard) and easily ruined using a Philips screw diver.

From memory (so not 100% sure) removal of the 3 screws at the bottom optic part is all that is required, but the relay lens holder part is very sticky, the relay lens is a cylinder !, I damaged the cylinder lens inside once prying it loose.

[PeteM]

Small foam swabs and lighter fluid or its equivalent can be used to thoroughly clean off the rails. Once you've done that, a very small amount of most any light grease should do - NLG1 or even NLG2 - lots of past references on this site. I like silicone greases that don't outgas, taking care to keep them away from lens surfaces. A drop or two of oil is a bit too free-running.

Whether you remove the bottom holder depends on if you can blow off any dust and have clean prism and lens surfaces left. If not, removing it will provide better access.

[Milou]

I don't know if this head is a CH2 or a BH2 head but the microscope basement has a BH-2 label!
Yes the bottom optic part should be very sticky as I couldn't remove it once the 3 screws are off....

The problem I have without taking of the 3 glued screws is one rail of the light path selector is completely hidden! Therefore impossible to clean and grease it again.
(see first picture)
It would be necessary to remove completely this part (selector) in order to clean and grease again both rails.....
I wonder if these 3 glued screws need really an alignment as in the second picture it could be seen their 3 bottom end in the black base part (see second picture in the bottom part)
I think they just hold support for light selector part....

[PeteM]

Things should go back properly aligned for a trinocular head rail. You can scratch a couple of faint witness lines in the metal carrier to housing if concerned.