Precise positioning sensors

[artem]

kender positioning site:edaboard.com

Hello

I need to position or ground a mechanical system during construction. I need a sensor to detect a zero mechanical point. Precision home mechanical switches are available but too costly - 3-5 um repetitive accuracy costs more than 100 Euro .

Actually 10 um precision is affordable . I guess the easiest way to build such is to use LVDS . Since i need to get repetitive result on 1 point LVDS full scale linearity is not of importance. Just i have a problem with finding cores for LVDS . Need Ni(40-60 ) Fe (rest) alloy . May i use ferrite roads for magnetic antennas as LVDS core?

The second alternative is to use quadrant photodiode with laser ligth but it is costly too - Hamamatsu is above 100 Euro per pcs.

Third alternative - electrical contact based on beariong balls . DIY constructions claim 10 um for digitizing probe made with this method .

Any suggestions ?

 

[kender]

Hey, I don't know the direct answer to your question. But I think, you've come across some interesting devices in your search. Could you post links to the datasheets for the 5um accurate switches?

You could also post your question to the group dedicated to sensors: **broken link removed**

 

[artem]

Hey, I don't know the direct answer to your question. But I think, you've come across some interesting devices in your search. Could you post links to the datasheets for the 5um accurate switches?

You could also post your question to the group dedicated to sensors: **broken link removed**

http://sensor.baumerelectric.com/productnavigator/scripts/level2.php?pid=&cat=CONFMechanische_Praezisionsschalter_My_Com&ptk=&psg=myPG|My_Com_Praezisionsschalter&language=en&country=TR&header=Turkey+%2F+Ilke+Otomasyon&orderby=TM_Mech_Familie|asc&restrict=&specialSort=1

repeatability < 0,001 mm

 

[Ayman Sharif]

Hello
Consider using linear encoder. This type of sensors has steps from 0.1 mm down to 0.1 um.

 

[artem]

are you about magnetic, magnitostrictive, optical or other types ? Could you please be more specific?

Added after 1 minutes:

It is possible to make ~ 10 um resolution switch based on patented touch probe. For details:

**broken link removed**

 

[FvM]

You never mentioned how many degrees of freedom exist for the object position in your application.
This would be an important condition in selection a suitable sensing principle. Also the opportunity
to have mounting fixtures at one or both involved parts.

 

[artem]

There is linear guide and ball bearing attached to base and i need to detect motion along one axis with fixture attached to linear guide base. And there is much room to play with it as i have access to mechanical workshop.

Somebody does have information about repeatability (around 5-10 mcirons) of DIY LVDS for minimum output signal for LVDS core based on ferrite cylinder ?