Unusual Switch / sensor needed Very Small.

[milmat1]

I need to detect the motion of a netting material as it moves by a small window.
The material is a monofilament netting with 3/4" squares. I can use a very tint whisker / wobble stick type of switch if I could find one.
An optical sensor of any type might be hard to use. It would need a small sensing window(length) because of other parts below the netting.

Anyone know of a manufacturer of very small limit / whisker / wobble switches..?

I could let the whisker stick down into the squares, it would "Bump" as the material went past. It would have to have a very low tension...

Any Ideas???

 

[gclshortt]

How about a small adjustable capacitive type proximity sensor.
http://www.automationdirect.com/static/specs/prox12mmcapcm.pdf

You can mount the sensor against the glass window and adjust the sensitivity to tune out the glass. Anything touching the glass should then trigger the sensor.

Note: This would have to be experimented with to ensure it would work in your application.

Just a thought,
Regards,

 

[milmat1]

How about a small adjustable capacitive type proximity sensor.
http://www.automationdirect.com/static/specs/prox12mmcapcm.pdf

You can mount the sensor against the glass window and adjust the sensitivity to tune out the glass. Anything touching the glass should then trigger the sensor.

Note: This would have to be experimented with to ensure it would work in your application.

Just a thought,
Regards,

I used the term window, but it isn't an actual window. I just have a small "Area" to look through...Sorry !!

 

[gclshortt]

The proximity capacitive sensor may still work for your application. If you use a shielded type that is threaded to the end.
You would have to test to pick up the netting material.

 

[milmat1]

Agreed, I see some that are 6 - 30 mm and adjustable with both foreground and background suppression...IF they will detect the small surface area of the netting ?

 

[rrparker07]

I've had very good results using these laser sensors from Keyence. The GV series in the link below are a little pricey but they have the most options like setting up the viewing window, timers, etc.

http://www.keyence.com/products/sensor/laser/gv/index.jsp

Good luck,
Roy

 

[jaden]

You might be able to use a photo sensor with a fiber optic sensing head. That allows you to make a custom mask to sense thru.

 

[milmat1]

I've had very good results using these laser sensors from Keyence. The GV series in the link below are a little pricey but they have the most options like setting up the viewing window, timers, etc.

http://www.keyence.com/products/sensor/laser/gv/index.jsp

Good luck,
Roy

Those look very interesting. I'll try to post a pic of the material...

 

[milmat1]

 

[dploof23]

You said you can drop a whisker type switch down into the netting? Could you put a reflector on the other side and use a retroreflective photoeye? There are also other style beam sensors that would detect the breaks in the beam as the webbing passed. Should be fairly inexpensive too.

 

[rootboy]

Are you trying to count the squares, or just that the netting is there?

 

[Rob S.]

What if you have the movement of the netting force the rotation of a roller , and sense the movement of the roller . Just a thought.

 

[Doug-P]

Background suppression laser?

http://ab.rockwellautomation.com/Sensors-Switches/Laser-Sensors/Short-Range-Laser-Sensors

 

[BITS N BYTES]

Give Tri-Tronics a call.
They have NEVER failed us in finding a solution to our sensing needs.
Made in the USA and great support!!

http://www.ttco.com/

 

[shooter]

why not use an encoder on the shaft of the roll?