Linear and rotary movement of a shaft

[harshith]

hi
i am going to design a parallel plate rheometer as a part of my project.in parallel plate rheometer, the fluid is sandwitched between the plates and rotation is given to the top plate.top plate is made with shaft, rotation is provided to the shaft by servomotor and for placing the fluid and removing the fluid,the top plate has to move up and down.here my problem is how to move the plate up and down , how to maintain the gap (0.8mm ,0.9mm)precisely and how to maintain parallelism of two plates with in microns.
please help me in this.very urgent.

 

[Danger]

Welcome to PF, Hargarbageh.
My first thought in this matter would be an optical stage as used in holography. The drive is usually by a screw-jack mechanism, and can be incredibly precise. I'm afraid that I don't know enough to give you more information. I'm sure that others here can, though.

 

[oswaler]

I understand the importance of precision and accuracy in experimental design. In order to maintain the desired gap and parallelism of the plates in your parallel plate rheometer, I would recommend using a combination of linear and rotary movement of the shaft. This can be achieved by using a stepper motor or a linear actuator to move the top plate up and down, while the servomotor provides the rotational movement.

To ensure precise control of the gap, you can incorporate sensors or limit switches that will signal when the desired gap has been reached. Additionally, using high-precision components and regularly calibrating your equipment can help maintain the desired gap and parallelism within microns.

I would also suggest consulting with experts in the field of rheology or precision engineering for further guidance and assistance in designing your parallel plate rheometer. Good luck with your project!