Reinforced 15, 17, 20 mm Ball Mount, AMPS 30×38mm

This is a ball-mount adapter built around the AMPS 30 × 38 mm mounting pattern, provided in 15mm, 17mm and 20mm ball versions via separate print profiles.

Many mobile-electronics accessories—phone mounts, GPS units, camera brackets, small displays, etc.—use one of these ball sizes and/or the AMPS base standard. The popular (but pricey) ProClip/Brodit car-mount adapters often use the AMPS standard.  There are also various available ball/socket mounts that work with Magsafe.

Also see my compression socket adapters in 17 mm ball size (here) and 20mm ball size (here), which mate with these ball adapters.  In combination, the two parts form a swivel mount between two AMPS-compatible components, such as a bracket and a phone holder.  See my  Vehicle Mounting Parts Collection for additional related components.

The model has internal geometry intended to maintain strength when printed upright. PETG has seemed strong enough, but for added strength you can screw an M4 (M3 for the 15mm version) flat-head bolt (25–30 mm long) into the center bore of the part. This bolt can also be used for mounting the cylindrical-base version.  

There are three versions on each plate:
• AMPS-plate version – includes the four AMPS mounting holes (30 mm × 38 mm)
• AMPS-plate version with nut traps – recesses to receive M4 nuts
• Cylindrical-base version – has a 28 mm diameter base that can be glued to another piece or attached with the central M4 bolt mentioned above

In my limited testing, Bambu Lab PETG HF has produced parts with by far the best clamping and smoothest swivel friction in this application, compared to PCTG and other PETGs.