# Kinematics of Invisible Hinge (Invisible Hinge with 7 Axes)

the gap between the panels must be (0 mm)
Harald

Harald

Maybe someone can send a ready solution in Grasshopper or explain in simple terms the logic of movement along the axes (how can I build dependencies in Grasshopper).

Harald

I did this a while ago with some constraints in Kangaroo, but it’s complicated

It was a lot of trial and error until I found the right specs.

The linkage was used on a mobile folding mini ramp for skateboarding.

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Hi Martin,

Thanks a lot for the quick response/support.
Tell me please, can I somehow achieve that the space marked with a red arrow is equal to 0mm?

Harald

I don’t know, sorry.

Now the gap between panels is 46.5 mm.
Harald

Here’s a setup where the linkage is defined by the initial positions of those 7 points
hinge.gh (14.7 KB)

You can adjust the positions to get the gaps you want

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Thank you very much Daniel.
I see you have a 90 degree opening I can adjust the in you Grasshopper file to 180 degrees?
Harald

The range of the angle slider in the definition is what is controlling the range of the motion. Right click it and Edit to change the Max value.

Daniel,

To achieve this result (picture in app.), do I need 7 axes or can I use fewer axes?
I am unable to achieve the desired result (I am not very strong in kinematics).

Harald

Daniel,

That is this the maximum degree that I could open.

Harald

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Could someone suggest a platform where I can intuitively calculate dependencies (kinematics) for similar tasks?
Harald

If you look at the Soss hinge pictured above, you can see that one of the hinges is actually sliding back and forth. I attached a Rhino model of a Soss hinge, maybe you have this already? Not sure how correct this model is but I think you should be able to retrieve the dimensions and hinge axis.

soss.3dm (3.1 MB)

Thanks Martin,

Yes, I have a similar model, but I can’t establish a link between the axes.

Harald

What do you need this for?

Soss hinge, not really fully constrained yet, but:

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Thanks Martin,

But I need that when the panels turn 180 degrees (there was no gap between them).

Harald

Martin,

Could you tell me with which component in the Grasshopper I can visualize the rotation axes, as shown in your video?

Harald

Martin,

Could you send me the Grasshopper file of this hinge, what are you demonstrating?

Harald

I think you are mis-interpreting that.
That hinge is meant to be put into wood doors (or else), where you have to cut/mill the correct “blind” hole for the hinge.
You don’t want to have the hinge visible from one side of the door (it’s an “invisible” hinge), so you have wood all around the hinge.
There is little-to-none gap, if you design correctly the holes in the door.

The hinge itself have a gap, but the gap is occupied by the door, usually.

… still, you want to have a minimum gap, because if the door touch near the virtual rotation point, huge strengths will apply (long lever), breaking your hinge …

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