What kind of pivoting to use?

Hi All, This is my first post. After reading hours of posts on core77, I think this place if full of creative geniuses.

I am looking for a permanent way to hold together a leg between 2 plastic pieces. I want the shaft that goes in the hole to be hollow, cause i plan to pass something through it. I have attached an image with the dimensions.

The leg (center) is aluminum and the plastic parts on either side are delrin. I want the fastner that holds the leg and the plastic together to also help in restrictive rotation (a little bit of torque) so that alittle force is required to rotated the leg about the hollow pivot point (the shaft).

Here are the options i was thinking so far:

  1. Custom aluminum eyelets (contacted manufacturers and seems like the tooling for this will be expensive, and don’t know if they have enough space to install these, see the image)
  2. Plastic shaft with one flanged end and the other side with clips or something like a grommet and maybe use O-rings to offer the torque rotation (will the O-rings wear out after a while?)
  3. Get a thin aluminum tube and flange both ends (not sure what kind of tool we will use or if there is enough space)

Guys please share your thoughts and any ideas? I am open to modify the dimensions if needed and am trying to get a cost effective method thats cheap for mass production.

PS: sorry for the enlarged images

Thanks for all your help in advance.


Anyone, any suggestions? :frowning:

A “Split Pin”.

A center knurled pin will lock into the aluminum.

Friction joints on delrin will loosen, so maybe tight fit with a silicon grease.

I think Nxakt is right, a split pin is probably the way to go. You might find it under roll pin as well. There are also coiled pins, I’m not sure which is more appropriate. Either will provide a outward force that holds it in place.

As for using O-rings for rotation resistance, some faucet handles and spouts use that method to create a nice feel. With a little lube they’ll last a long time (think of how many cycles a handle goes through).

Nxakt and seurban, Thank you guys for the response. How would you hold the roll/split pin in place?

The pin is spring material, force fit aka interference fit into the hole compresses it and locks it in place. The forces are all acting on the pin in shear direction and nothing will push it out.