What hinge mechanism can be used to rotate a metal piece on another metal piece? 1

[U Offor]

I am trying to find some type of mechanism where I can have a smooth but not too stiff rotation between two metal pieces. I was thinking of putting a shoulder screw through the pieces (the pieces will be side by side) and a nut at the end.

A real world example I can think of is how when you're unfolding a ladder, the part that unfolds has a joint where rotation occurs. It's smooth and stiff enough that you can let go midway and the ladder wouldn't collapse inward, but not too stiff that you have to apply so much force to unfold the ladder. What do they use to do that?

I attached a visual image of the hinge I'm thinking about.

 

[IRstuff]

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[U Offor]

@IRStuff

In the picture, is the large part of the hinge lock mechanism and the hole it goes into threaded?

 

[IRstuff]

No threads; there are two specific locations that the hinge locks for the Little Giant ladder.

TTFN (ta ta for now)
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[SnTMan]

I am going to guess the "smooth but not too stiff rotation" in the OP's example relies on friction between mating parts. In turn, that relies on clamping force of the bolt & nut.

Regards,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[TheTick]

Friction discs and orbit-formed pins.

 

[aer0s]

I would look at fluid tripod heads, they are concerned with smooth rotational motion

https://youtu.be/jlJ-dRw-DyY?t=470

A layer of grease, delrin disk, or other friction reducing material can be used. If you have the space and budget, angular bearings or tapered roller with a pin/bolt at the center of the two machined metal plates, then as you go further out from the center of the plates you could have flat plates close together with a small gap that you fill with grease for the same effect.

igus makes a slewing bearing that does something similar.

Or a rotational damper but then the parts need to be geared.

https://www.takachiho-kk.co.jp/en/prod/mechanical/damper/select.html