Electronic hobbyists: where to buy things like rheostats, etc

[Buick355]

I'm trying to fix our stupid elliptical machine, the servo for the resistance isn't moving, I found that the control board/console is no longer changing the voltage to the servo in order to move it. Instead of buying a $500 console for an exercise machine that's worth $300 I figured I'd rig it up with a knob to change the voltage to the servo to control manually. Here's what I need to do: take a 6V reference and split it in to two, but be able to vary it. So if one circuit has 2V, the other circuit would have 4V, or that's the way I understand that it determines the position of the servo. So I need a device that I can wire in to do this. Where can I buy something like this? Any suggestions are appreciated!

Here's what the resistance motor/servo looks like:

[Samhain]

You can find them at RadioShack, if not there Tanners in Carrolton.

[Buick355]

You can find them at RadioShack, if not there Tanners in Carrolton.

I was thinking Radioshack also, but last time I went in there it seemed like they were getting away from the electronic hobby stuff and more into phones and gadgets. I'll stop by one though this week and see what they have. I've never been in Tanner's. I might try that if I get out near Carrollton.

Am I on the right track though? I haven't found a specific device that splits the voltage in a way that you can vary it between two circuits.

[Samhain]

Sounds like the most simple route.

[BERNIE MOSFET]

Fry's has some electronic components, potentiometers and such; I'd imagine they will likely have a panel mount rheostat/knob setup. Possibly also Altex, but that wouldn't be my first choice to look.

If you aren't in big hurry you could also order one from digikey or mouser electronics and get it in a day or two.