Olympus CH-2 Issue - Stage Lifting

[heyitsmedusty]

I use an Olympus CH-2 microscope, mainly for reflected light photography of micrometeorites. I'm still very much a beginner, but I love the microscope for this purpose so far!

My issues is that when using my x-y stage control knob, sometimes the stage clip/slide holder mechanism lifts up and allows the slide to slip underneath. I poked around to try tightening anything that feels loose, but couldn't find any apparent issues. There must be a specific screw or thumb screw that keeps the slide holder mechanism flush against the stage while using the x-y stage control knob, right?

If my description of the problem isn't enough to understand the problem, I can get photos and attach later.

Any help is appreciated, especially with photos or illustrations!

Cryptocrystalline Micrometeorite

cryptocrystalline-micrometeorite.jpg (180.03 KiB) Viewed 1072 times

[woyjwjl]

http://www.alanwood.net/olympus/downloads.html#bh


Unless the rack is broken.....

[apochronaut]

If I understand you correctly, the curved finger of the slide holder rides up and over the corner of the slide?

[apochronaut]

Before this thread becomes buried, my question was based on a similar experience with about 10 well used scopes but I can't specifically remember an Olympus.
After repeated use , the pivot sleeve bearing that the stage finger rotates on can become worn enough that the finger can wiggle up and down some. It then can skip over the corner of the slide and when this happens enough, the repeated upward pressure exacerbates the problemand can slightly deform the finger upwards. The brass that many of those fingers, especially 50's to 80's Japanese ones , are made of is quite soft and low in temper. Since the emergence of China, South Korea and Taiwan as industrial powers, Japan uses less domestically produced recycled material.
The best design used a 3 part construction, with a floating sleeve bearing in the middle.
Occasionally just lubricating with a very heavy grease will solve the problem.
If, when looking along the stage table you see that there is a noticeable gap or flex in the finger, remove the mechanism from the stage and just ever so slightly bend the finger down slightly. You aren't really bending it but flexing it downwards about a 1/32" or less. You will have to refit it a couple of times maybe, in order to get it just right.
The problem is worse with thin slides. Sometimes just switching to a slightly thicker slide will solve the issue.

You mentioned that it happens when you move the slide. There could be something, a bit of looseness in the X motion mechanism that causes the finger to lift slightly.

[GerryR]

On the X-Y units on my 'scopes there is a small nylon pad on the bottom so that the actual mechanism does not actually rub on the table when in motion. Perhaps some accumulation of debris under the pad has lifted the mechanism enough for it to slip over the slide. Just a thought.

[heyitsmedusty]

Thank you for the replies, very helpful so far. After taking the stage off and wiggling it around to see where the play was coming from, it looks like the teeth of the gears of the y-movement are not seated as tightly together as they should be. They never become disengaged, but there is just enough play that when using either the X or Y movement knob, you can accidentally lift the finger enough to let the slide slip under it.

For the life of me, I can't find a screw that brings the gears closer together. I checked every exposed screw (none needed any tightening, all were extremely secure).

@apochronaut's suggestion of flexing the finger down might solve for it, so I'll try that next.