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I am designing a 3-stage platform like that of a 3D printer. Three stages correspond to X, Y, and Z axis. There is a nozzle with fixed height about the z-stage platform.

The stages are pretty accurate with a resolution of 1 micron.

Now I need to adjust the height of the z stage so that the distance between the nozzle and the stage surface is about 10±1 microns.

I have already checked some of the high-resolution distance sensors, but they are way too expensive.

I wonder if there are any alternate methods to achieve that.

706Astor
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Jarvis Du
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  • Perhaps you can get better answers if you specify what your intention is - 1µm seems pretty steep for virtually any application. – Sanchises Jul 02 '15 at 21:18
  • @sanchises Basically I just need to adjust the height difference between the nozzle tip and the surface to be 10 microns. I don't have a requirement of resolution, as long as it is reasonable. – Jarvis Du Jul 02 '15 at 22:01
  • What is your surface? If it's a reasonably smooth solid: most air bearings are very much capable of having a µm-order distance from a surface, so you could just rest your nozzle with air bearings on your surface - no complicated control technology necessary. – Sanchises Jul 03 '15 at 08:01
  • The surface is reasonably smooth, but the flatness may be not. So we still need a sensor for on-line height adjusting. – Jarvis Du Jul 03 '15 at 14:07

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Not going to happen. Your limiting factor here is not the sensor, so you can forget about that. Any kind of normal bearing or gear mechanism can get nowhere near 1 micron. Even CNC mills and lathes costing $500,000+ cannot get that kind of precision and they have bearings that cost thousands of dollars each.

A micron is very small distance. Just to give you some idea, a precision grinder costing big bucks has a vertical adjustment graduated in 0.0001" inches which means the mechanism has to be precise at least to 0.00005" to deliver that granuality (ten thousandths of an inch). A micron is even smaller than that.

Wallace Park
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