Guide for making STLs that are easy to integrate

The Assembler can load and scale any STL or OBJ file, but some things make it easier.

1. Scale should me in mm.
2. The part should be oriented with Z up and Y axis forward. That is, as if the arm is straight along the Y axis, so elbow, wrist, knuckle, and finger joints should be in a straight line. This makes it easiest to translate and scale the parts to the actual arm position for previewing.
3. The object should have the relevant control point at the origin, the [0,0,0] coordinate.

• Gauntlet: origin in center of wrist joint
• Palm: origin in center of wrist joint
• Thumb and Finger Proximal: origin in center of knuckle
• Thumb and Finger Distal: origin in center of joint between proximal and distal

Measurements

The key measurements for the parts should be documented. These are:

• Gauntlet: width at outside of wrist end of gauntlet (to fit inside palm)
• Palm: width at inside of wrist (to fit gauntlet), and outside of knuckles (to match other hand)
• Proximals: distance from knuckle to joint
• Distals: distance from joint to tip

All parts: Rotation and offset for printing, so that it's flat on the plane of Z=0. For example, if a part should be rotated upside down and raised 7mm. This allows Handomatic to render the part for printing and to combine parts into printable plates.

Other parts

If there are additional parts, such as snap pins, they should be provided as separate files so that they can be positioned for previewing and for printing. For those parts, please place the origin at the center bottom of the part, and document:

• How many to print
• Where they fit in relation to the other parts (so that they can be previewed jn place)

Future

When we add this capability to Handomatic, joint holes should be removed from parts, so that they can be replaced in software after scaling and translation.