Need help with Servo Coupler

I'm trying to use a threaded rod with a servo coupler and I need the rod to stay straight.
I'm currently using an Actobotics futaba servo shaft coupler.
I am attaching a Parallax Feedback 360 servo to a 1/4" threaded rod.

When I tighten the set screw, it pushes the rod slightly off center and slightly angles it.
This is creating a lot of wobble. I need the rod to stay straight!

Is there a better way to do this?
Is there a better coupler I could use??




  • Apparently the rod is somewhat loose-fitting in the coupler. To fix that, slip a small piece of paper or aluminum foil along the shaft opposite the setscrew. It may take more than one, especially if the shaft is threaded all the way to the end.

    “Perfection is achieved not when there is nothing more to add, but when there is nothing left to take away. -Antoine de Saint-Exupery
  • A little bit of PEX tubing and a shirt pin goes a long way. The 1/4" all thread friction fits nicely into the PEX. a nut can also be used to lock the connection. The shirt pin acts as a cotter pin between the PEX and the servo. You will need to drill a tiny hole to accommodate the pin going through the PEX and the servo. A small bend in the pin and your done.

    Beau Schwabe --- Robotics applications- PCB design, embedded software, and mechanical
    Oklahoma Robotics - - [EMAIL=""][/EMAIL] ෴෴ - [EMAIL=""][/EMAIL] ෴෴

  • Thin wall brass tubing from a hobby store can also be used to create a snug fit between the threaded rod and the servo coupler.
    In science there is no authority. There is only experiment.
    Life is unpredictable. Eat dessert first.
  • These are great ideas!
    Thanks everyone !
    I will start testing them out !

  • ercoerco Posts: 19,584
    I usually do things by brute force, ignorance & experimentation. Here I align a homemade "coupler" made of JB Weld (AKA epoxy) and test the alignment while the epoxy sets up. Definitely use quick-set epoxy here!

    "When you make a thing, a thing that is new, it is so complicated making it that it is bound to be ugly. But those that make it after you, they don’t have to worry about making it. And they can make it pretty, and so everybody can like it when others make it after you."

    - Pablo Picasso
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