The MBS provides a platform for Canadarm2 and Special Purpose Dexterous Manipulator (SPDM) a.k.a., Dextre via four power data grapple fixtures located at each corner of the structure. The unit also provides two additional locations for payload attachment. The Payload/Orbital Replacement Units Accomodations (POA) is located on the port side of the component. This device looks and functions like the latching end effector (LEE) units found in each end of Canadarm2. The second location, found on the zenith side of the component, is called the MBS Common Attachment System (MCAS). This location accomodates attachment of various experiment and storage platforms and was used to transport External Stowage Platform 3 (ESP-3) from its location on the P3 truss to another location on the S3 truss on January 12, 2010.
I started working on this component near the end of the S0 Truss build effort (June 24, 2018). The unit is comprised of a single parts page and a page used for backing the main body, which are part of ISS combo kit #1 from AXM. Instructions (24 pages) for the component can be found here.
I started by cutting out the lower connection plate.
Next, I extruded parts for the the upper platform and orbital replacement unit (ORU) base, Canadian Remote Power Controller Module (CRPCM), and MBS Computer Units (MCU).
I formed the upper cradle platform, lower connection plate, and backed both parts.
The lower connection plate was then attached to the upper cradle platform. Magnets were placed at each corner of the lower connection plate to enable magnetic connection to the MT.
Next, I formed and backed the Umbilical Mechanism Assembly (UMA) and attached it to the upper cradle assembly.
I then attached the MCAS platform. A magnet was placed under the platform to accommodate attachment of future payload platforms.
Next, I built the ORU Base Assembly (OBA).
I then built the POA.
I affixed the OBA to the nadir side of the upper cradle platform. I then built the four power data grapple fixtures (PDGF), placing a magnet under the face of each fixture to accommodate future attachment of robotic arms. I consulted the instructions regarding the proper angle to glue each PDGF. Trunnion pins were added to the port and starboard ends of the upper cradle platform.
The MBS was then transported to my office and attached to the MT, as seen during STS-111 while the Leonardo MPLM was berthed to the Unity nadir port.
This photo depicts the station configuration at the end of STS-111 after the Leonardo MPLM was unberthed and the Canadarm2 was relocated to the lower starboard PDGF connection.
Next up, the S1 Truss.
