MW Turntable 

This view shows the components in a fully assembled form

608-2Z_-_Deep_groove_ball_bearing_v1

mesh_0

Turntable_interface_part_v12

mesh_1

bearing_seat_v3

mesh_2

arm_retainer_v2

mesh_3

arm_v1

mesh_4

arm_v1_1

mesh_5

arm_v1_2

mesh_6

This view shows how each component fit relative to each other

The three petal shape was reverse engineered from the original coupling part to reduce backlash and fit into the glass turntable plate.

Glass Plate Coupling

The shaft diameter was made to have an transition fit with the bearing.

A chamfer was added to guide the shaft into the bearing hole. This helps with assembly.

A small lip around the base of the shaft is used to ensure the three petals do not rub against the bearing and adjacent parts.

A bearing was salvaged from a skateboard and used to reduce friction when spinning the plate. Will be replaced with a loose fit hole in the bearing seat for future iterations since food was pushed away too easily when we tried to grab it.

A calculation using ISO 128 was used to validate the bearing life was sufficient with a RPM of 1, an axial load of 50 lbf, and a radial load of 1 lbf.

608-2Z-Deep Groove Ball Bearing

The bearing seat was used to elevate the bearing to a height that was 0.5 mm taller than the wheels on the ring such that most of the load goes through the rotating part to keep it in place.

The chamfered inner edge helps guide the bearing in during assembly.

Bearing Seat

Arm holder uses dovetail joint inspired connection to the arms with the corners of the connection considering that the minimum outer radius my 3D printer can make is 1mm.

Future iteration will combine the bearing holder and the arm retainer into a single part.

Arm Retainer/Holder

The "lip" under the dovetail joint inspired connection serves two functions. 

First, the top of the arm must be assembled facing up. 

Second, the assembly will hold the arms should the turntable be relocated. Though this issue can be solved by simply ensuring a tighter fit between the dovetail connections, it may require tighter tolerances.

Inspired by classic steering wheels these act as spokes to hold the microwave turntable's wheel ring in place.

Like in the arm retainer/holder, the minimum bend radius in the design was limited to 1 mm due to manufacturing limits
