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Return to Center Pot for steering & rocker pot for throttle? — Parallax Forums

Return to Center Pot for steering & rocker pot for throttle?

FalconFalcon Posts: 191
edited 2012-10-31 16:30 in Robotics
I'm working on a remote control for a 4 wheeled robot. I've been using a Futaba 9C but I just don't care for steering with a joystick.

I want to put a steering-wheel on the remote control like the ones that come on car/truck remotes. I have several Traxxas car/truck remotes and they all have mechanical pieces and a spring external to the pot to bring the steering wheel back to the center position.

Does anyone know of a potentiometer with a built-in return-to-center (rtc) feature? I suppose an encoder could be used too.

I'd be willing to rip apart a PC or game controller if it has a pot with a rtc feature. I thought about using a bunge cord to return the pot to center but I'd need a pot with the shaft sticking out the back to attach the bunge to.

I would also like a rocker-style pot for the throttle control that would rtc.

Any thoughts or suggestions.


falcon

Comments

  • NWCCTVNWCCTV Posts: 3,629
    edited 2012-10-29 13:46
    If this one will not work continue looking on their site. http://www.mouser.com/ProductDetail/Electroswitch/E3G0603N-2/?qs=%2fha2pyFadujz2DOT9XRPCV0umtJim9IaDzH3n2AMMgRJEDxGusYZDA%3d%3d

    or here: http://www.etisystems.com/joystickselect.asp
  • W9GFOW9GFO Posts: 4,010
    edited 2012-10-29 14:02
    http://www.ebay.com/itm/TWO-REMOTE-CONTROLS-3-CHRAGERS-ONE-PARTS-CAR-TRAXXAS-LOT-FUTABA-T2PH-/270996600678?pt=US_Character_Radio_Control_Toys&hash=item3f18a7f766



    http://www.ebay.com/itm/Traxxas-TQ3-Remote-/181004954144?pt=US_Character_Radio_Control_Toys&hash=item2a24bc6a20
  • FalconFalcon Posts: 191
    edited 2012-10-29 16:49
    NWCCTV,
    That Mouser part was a 3 position switch, not a pot. I looked around their site and found no rtc pots. Have you ordered from ETI Systems? They have a rocker pot that looks like it would work for the throttle.

    W9GFO,
    Both of those Ebay auctions are for Trassax controllers. I have several of them already and the rtc feature is external to the pot. I'm trying to find a pot with an internal rtc.

    I appreciate the replies,

    falcon
  • ercoerco Posts: 20,256
    edited 2012-10-29 17:49
    They're out there, but not necessarily cheap: http://potentiometer.us/ http://joysticksales.net/potentiometers/singleturn_potentiometer/single_turn_springreturn_potentiometer.htm

    As Rich suggested, repurposing an RC pot with external mechanism is likely a more affordable option.

    Somewhere at home I have some beautiful tiny 2-axis return to center joysticks with a very nice feel. If I find a manufacturer on them, I'll advise in hopes that they may have 1-axis pots.
  • W9GFOW9GFO Posts: 4,010
    edited 2012-10-29 18:47
    I don't know of any rotary pots that return to center. You could use a mini-joystick as a rotary input by removing the thumbstick and fitting a disk with a slot that engages the stub. The disk would have an axis of rotation just below the joystick so that rotating it will move the slot - which moves the joystick. Does that make sense?
  • ercoerco Posts: 20,256
    edited 2012-10-30 01:16
    About the cutest little joysticks you've ever seen, but sadly there's no helpful info. PS RSF is stamped into the metal, two 10K pots. A buddy gave me two of these years ago, but he's long gone and I can't find him to ask what his source was.
    joy.jpg
    980 x 735 - 124K
    joy.jpg 124.3K
  • FalconFalcon Posts: 191
    edited 2012-10-30 15:51
    W9GFO wrote: »
    I don't know of any rotary pots that return to center. You could use a mini-joystick as a rotary input by removing the thumbstick and fitting a disk with a slot that engages the stub. The disk would have an axis of rotation just below the joystick so that rotating it will move the slot - which moves the joystick. Does that make sense?

    W9GF0
    I can picture what you described, and I think that could work. I ripped open an old thrustmaster PC steering wheel and found a typical long-shaft pot with a bunge cord attached to it. The cord was stretched and each end was anchored. That provided the rtc. I can use normal pots while I do the electrical design. This should give me more time to figure out the best solution.

    Thanks for your advice.

    falcon
  • FalconFalcon Posts: 191
    edited 2012-10-31 16:30
    I think I came with another idea that will work. First, use four 1" standoffs to mount a 2" x 3" metal plate directly behind the front panel at the location of the pot. Then use a long-shaft pot and mount it to that small plate from behind with the shaft sticking through a hole in the front panel. Then drill a small hole through the shaft cross-wise between the plate and the front panel. Attach a ~1.5" pin(or 4-40 bolt) sticking through the hole with a small loop on the end. Then, using either springs or small bungee, attach the pin to two of the standoffs on one of the long sides. This "should" spring the pot back to the center position depending on how much force it takes to move the shaft.

    Opinions?

    falcon
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