Troubleshooting for the coarse adjustment part of the microscope
The main faults of the coarse adjustment part of the microscope are automatic sliding or inconsistent tightness during lifting. The so-called automatic sliding refers to the phenomenon that the lens barrel, lens arm or stage automatically and slowly falls down under the action of its own weight without adjustment when it is stationary at a certain position. The reason is that the weight of the lens barrel, lens arm or stage itself is greater than the static friction force. The solution is to increase the static friction force to counteract the gravity of the lens barrel or lens arm itself.
For the coarse adjustment structure of the lens barrel and most binocular microscopes, when the lens arm slides down automatically, you can hold the stop pulley inside the coarse adjustment handwheel with your hands respectively, and tighten them clockwise with both hands, which can stop the sliding. If it doesn't work, you should ask professional personnel for repair.
The automatic sliding of the lens barrel often gives people the illusion that it is caused by the too loose fit between the gear and the rack. So people add gaskets under the rack. In this way, although the sliding of the lens barrel can be stopped temporarily, the gear and rack will be in an abnormal meshing state. As a result of the movement, both the gear and the rack will be deformed, especially when the gasket is uneven, the deformation of the rack will be more serious. As a result, some parts are tightly engaged and some are loosely engaged. Therefore, this method should not be adopted.
In addition, due to the long-term lack of maintenance of the coarse adjustment structure, the lubricating oil dries up, which will cause an uncomfortable feeling during lifting, and even the friction sound of the parts can be heard. At this time, the mechanical device can be disassembled, cleaned, greased and reassembled.
