Resistive Wire Selection For Linear Potentiometer

[jcarsw04]

I'm trying to build a ball and beam balance control system. I was thinking of using a metallic ball and two wires to make a linear potentiometer to give the ball's position. I'm not sure what to use as the resistive wire. Most wire I find doesn't seem to provide a sizable amount of resistance. I know I can amplify the output but I also want my system to be less susceptible to noise and accurate. I would also be open to other suggestions as to what I can use as a position sensor for the ball on the beam. Could someone post a link to some good material to use for the resistive wire? The length of the beam is only 8 inches and the ball has a 5/16" diameter. Thank you for any help.

REF: http://en.wikipedia.org/wiki/Ball_and_beam

 

[gneill]

I'm trying to build a ball and beam balance control system. I was thinking of using a metallic ball and two wires to make a linear potentiometer to give the ball's position. I'm not sure what to use as the resistive wire. Most wire I find doesn't seem to provide a sizable amount of resistance. I know I can amplify the output but I also want my system to be less susceptible to noise and accurate. I would also be open to other suggestions as to what I can use as a position sensor for the ball on the beam. Could someone post a link to some good material to use for the resistive wire? The length of the beam is only 8 inches and the ball has a 5/16" diameter. Thank you for any help.

REF: http://en.wikipedia.org/wiki/Ball_and_beam

Maybe look into graphite rods (pencil leads).

http://www.troelsgravesen.dk/graphite.htm

 

[CWatters]

http://www.asee.org/documents/zones/zone1/2008/professional/ASEE12008_0012_paper.pdf

...the sensing of the ball position is by using two infrared
distance sensors. There is no tear and wear by the motion of the ball.

The Sharp GP2D12 infrared distance sensors[4] were chosen for the project because they were inexpensive and sensitive enough for registering the location of the ball on the beam. Also the infrared beam is narrowly confined that adjacent objects does not easily interfere with the detection of the ball position.

but check the minimium range for this sensor as your beam is shorter.