Step 1: Bottom Ring Base
Step 2: Bottom Ring
Now you need to make this shape. Here are the dimensions:
Lengths (mm) - Side 1: 0.668mm; Side 2: 0.447; Side 3: 0.3; Side 4: 0.358
Angles (degrees) - Angle between side 1 and 2: 129.3; Angle between side 2 and 3: 180; Angle between side 3 and 4: 103.5; Angle between side 4 and 1: 76.2
Once you have this shape extrude it by 0.75mm and uniformly scale it up by 2. Then move it into position like in the picture. Once it’s in position, subtract it from the ring base so that you have the cut ring.
Now filet both the bottom inside and outside edges of the ring by 0.045.
Now to make the spacer for the top ring, you need to a 2D sketch of the cut and it needs to match the shape exactly. I used the polyline and the 3 point curve to make the shape for mine. Once the shape is made, flip it over 180 degrees and move it to the left by -5.46mm to line it up exactly with the other side. Then extrude it by 0.25mm and move it 0.5mm. Then combine it with the ring so that they are on piece. Then filet both the inner and outer edges by 0.045.
Now we need to make the hole in the ring for the pin to fit in. First make a cylinder with a height 1 and a radius of 0.12. Then scale the cylinder up by 1.40 and move it into the position like in the picture. Also make sure that it goes all the way through the Ring. Once it’s in position, subtract it from the ring. Now make another cylinder with a radius 0.15 and a height of 1. Then scale the cylinder up by 1.40 and move into position directly over the hole we just made. Then move it down so that the top edge is in the ring the thickness of the filet, like in the picture.
We have finished the bottom ring! =)
Step 3: Top Ring
Top ring is complete and it is its place! : )
Step 4: The Pin
This is the 2D sketch of the pin that you need to make. I'll start with the length of the longest length of the sketch and then go clockwise: 0.46; 0.12; 0.045; 0.02; 0.06; 0.02; 0.355; 0.08. Now revolve the sketch a full 360 around the longest length on the left. This is the inner pin. Now for the outer pin:
Make this 2D sketch for the outer pin. Here are the dimensions starting with the length on the left that will be the axis of revolution: 0.0105; 0.08; 0.355; 0.02; 0.415; 0.02; 0.045; 0.12. Now revolve the sketch a full 360 around the longest length on the left.
Now put them together and make them one object.
Now you have to scale the pin by these factors:
Overall scale of 1.40.
Then: x and y of 1.23 and z of 0.6. After these are done scale the z axis by 1.05 again.
Now rotate it 90 degrees and move it into position on the ring.
Step 5: The Magnets and the Finishes
Now we have to cut a spot for and make the magnets that keep the ring closed.
First make a rectangle that is 0.3 by 0.4mm and another one that is 0.3 by 0.2.
Extruded both of these rectangles by 0.15 and duplicate them so that you have two of each.
Now move one of the bigger into the position shown and hide the bottom ring so that it is easier to see. Then subtract the rectangle from the ring.
Repeat this process with the bottom ring and hide the top ring.
Now position the two smaller rectangles (the magnets) into these new holes and make the part of each ring respectively.
Now a final touch, filet the edges of the cutout space on the bottom ring.
You’re Done! =)