- Joined
- May 3, 2020
- Messages
- 359
TL;DR What oil should I use for this propeller type damper? Pictures below.
I recently purchased a Gaertner toolmaker's microscope. I paid about 500 and another 100 $ or so in shipping. This was the most disappointing thing I've ever purchased off eBay. I paid too much and when it arrived, it was in bad, dirty, stinky shape to begin with. During shipping, it rattled loose from the wood box and beat the hell out of itself. The design of the XY stage is micrometer driven one way and sprung the other, so without restraint during shipping, it sloshed back and forth. Sheet metal was bent and one of the ball bearings fell out. The microscope was in such bad shape that I'm not sure what other damage was done in shipping.
Anyway, I took it all apart and worked it over with a nylon brush and WD40. Had to order a set of Bristol drivers because this thing has weird 6-spline screw heads. I'd never seen it before but it appears to be common in certain industries. You can buy the tools from Chapman, Bristol Wrench, or even McMaster. But I don't know where you would source fasteners with this type of drive. Cleaned the objective and eyepiece with kimwipes. There's still dust in the optical path and the angular measurement in the eyepiece doesn't move but I haven't pursued that, yet.
The damper in question is for the X axis. There is a trough for using end standards for the highest precision measurements. I think the idea is that you don't want the stage crashing into the end standard as it returns under spring tension. Anyway, I need to re-fill the reservoir and I wondered if you might have a suggestion for the type of oil to use.
The damage:
I didn't know how to disassemble this mechanism but I have watched a lot of wristwatch restoration videos so I assumed a light press fit on a rotating arbor. Although the gear did pull off easily, the arbor is fixed. The arbor was the most damaged part in this assembly. After a great deal of tapping and measurements with the cutest little square, I got bent it back to straight. After realizing that the arbor is fixed, it became apparent that it is a bearing surface that was very dirty.
I also put the compound gear on a bench center and checked it for axial runout. It is about +/- 0.007 in. I don't know how to fix it and the gear engagement is adequate even with this slight wobble. If there's a way to fix it, I'm all ears.
Note the 1-way mechanism. When the compound gear rotates CW, the damper disengages. When turning CCW, the damper is in effect. That 1-way effect is connected by a spring which is created with a slot cut into the arm. It's not in the photo but that arm drags on a boss on the underside the compound gear. Very clever.
Also note the fill hole and the tiny hole that serves as a plug.
Everything is fairly clean now and it's time to reassemble. Any thoughts on the oil I should use?
I recently purchased a Gaertner toolmaker's microscope. I paid about 500 and another 100 $ or so in shipping. This was the most disappointing thing I've ever purchased off eBay. I paid too much and when it arrived, it was in bad, dirty, stinky shape to begin with. During shipping, it rattled loose from the wood box and beat the hell out of itself. The design of the XY stage is micrometer driven one way and sprung the other, so without restraint during shipping, it sloshed back and forth. Sheet metal was bent and one of the ball bearings fell out. The microscope was in such bad shape that I'm not sure what other damage was done in shipping.
Anyway, I took it all apart and worked it over with a nylon brush and WD40. Had to order a set of Bristol drivers because this thing has weird 6-spline screw heads. I'd never seen it before but it appears to be common in certain industries. You can buy the tools from Chapman, Bristol Wrench, or even McMaster. But I don't know where you would source fasteners with this type of drive. Cleaned the objective and eyepiece with kimwipes. There's still dust in the optical path and the angular measurement in the eyepiece doesn't move but I haven't pursued that, yet.
The damper in question is for the X axis. There is a trough for using end standards for the highest precision measurements. I think the idea is that you don't want the stage crashing into the end standard as it returns under spring tension. Anyway, I need to re-fill the reservoir and I wondered if you might have a suggestion for the type of oil to use.
The damage:
I didn't know how to disassemble this mechanism but I have watched a lot of wristwatch restoration videos so I assumed a light press fit on a rotating arbor. Although the gear did pull off easily, the arbor is fixed. The arbor was the most damaged part in this assembly. After a great deal of tapping and measurements with the cutest little square, I got bent it back to straight. After realizing that the arbor is fixed, it became apparent that it is a bearing surface that was very dirty.
I also put the compound gear on a bench center and checked it for axial runout. It is about +/- 0.007 in. I don't know how to fix it and the gear engagement is adequate even with this slight wobble. If there's a way to fix it, I'm all ears.
Note the 1-way mechanism. When the compound gear rotates CW, the damper disengages. When turning CCW, the damper is in effect. That 1-way effect is connected by a spring which is created with a slot cut into the arm. It's not in the photo but that arm drags on a boss on the underside the compound gear. Very clever.
Also note the fill hole and the tiny hole that serves as a plug.
Everything is fairly clean now and it's time to reassemble. Any thoughts on the oil I should use?
