Multifunction Arm Hinge (e.g. for laptop holder)

Description

This model expands the Multifunctional Arm by a hinge. The included hinge was only for use as a vesa plate attachment. This adapter adds another socket to the hinge, so it can be used in the middle of the arm system and connect to another arm or holder.

It is compatible with the small arm system when scaled down to 60%. Thanks to toscdesign for testing. (Files will be added later)

Function

The images show the maxium rotation of the hinge, which overall is around 155°. Note that it rotates more in one direction and plan your arm assembly accordingly.

3D view

Printing

Before you print the hinge you should consider, where you want to install it and how far you want the hinge to rotate, because the amount of rotation is larger into the direction of the side, where it is connected to the rest of the arm. As the arm attachment side depends on the number of arm parts you want to use you should check, if you end up on the desired side. If not, you might print the arm parts mirrored to get there (see note).

Note:

The hinge works best when it is aligned vertically. The symmetry plane of the gear teeth is inclined 2.9° from the vertical axis.
To get a straight vertical alignment for the hinge: use the provided hinge_A and hinge_C files when using the standard mounts as they all have a matching orientation. If you mirrored parts through a certain plain you might need to use mirrored parts for the hinge as well, which are provided in an additional folder.

I used these print settings:
0.3 mm layers, 8 walls, 5 bottom, 5 top, 30% rectilinear infill.

1. print hinge_A
    
2. print hinge_B twice
   
   It should be oriented like this: 
   
   
   
   It can be printed without supports, which looked even better in my case.
   
   The overhangs do not need to look pretty as they won't be visible later and it does not really effect the stability. Just make sure to clean the parts enough so they fit together like this:
   
   
    
3. print hinge_C
   This must be printed with supports as shown in the picture.
   Note: the actual file is slightly modified from the shown image to improve printing the overhang.
   
   

Assembly

1. Slide two hinge_B on the hinge part of hinge_A, one from each side.
   Note that they must be rotated counterclockwise
2. Rotate the two hinge_B until they align
3. slide hinge_C over both of hinge_B
   You can do it as shown in the animation, which might lead to an overall slightly more stable arm - or from the other side which leads to a flipped connector (in which case you should use the hinge_C_alt_angle with mirrored gear teeth to keep the orientation).
   The side from which you slide hinge_C onto the rest must be the top if hinge_A is on the mounted side of the arm. Otherwise, while the parts hold quite tight due to friction, there is a chance of it sliding downwards!

Use case

I designed this for use with the laptop holder:

Updates

24-10-21

• edited hinge_C to have the socket in the same plane as the hinge_A part (as it was intended and is shown in the pictures and 3D-print. Must have been inadvertendly changed, when i improved the overhang part before uploading the files)
• For hinge_C, the base is now aligned in the same way as for hinge_A so that the relative alignment of the two sides remains the same.

25-01-05

• added alternative angle versions of hinge_A and hinge_C, as I realized the angle of the gear teeth I originally adopted from the vesa holder would lead to a mismatch. the previously hinge_A and hinge_C now are labeled hinge_A_alt_angle and hinge_C_alt_angle