When the all the parts for the first prototype were finished, there was some difficulty with the assembly of the fidget cube. The tolerances for the the frame where a very tight fit especially for the “fin and slot” side assembly. Shrinkage of the frame in comparison to the sides, especially for the TPU, deformed at slightly different amounts when we expected the sides to be an exact fit. As a result, there was extra post processing needed including some sanding needed to be done on each of the sides to make sure everything fit. For the next iteration of the design, each piece of the assembly will be corrected to make sure there was a better fit into the frame, as well as trying to make improvements on the functionality.
The rollerball assembly did not have enough clearance between the ball and the plate, and thus the ball was fused in place. For future iterations, the clearance will be increased to at least 0.4mm between the parts in the sub assembly. This should allow the ball to act more like a bearing.
Figure: Rollerball Prototype
The 5 button side also had movement issues. Unlike the roller ball side, this part had too thick of walls and therefore the button supports would not bend in order to allow movement. To remedy this problem, we are looking into creating an assembly within this side so that we can print these buttons out of TPU and provide more flexibility.
Figure: 5 Button Prototype
The joystick side printed well and has the desired movement. However, for future designs, we plan to increase the infill density to 100% in order to strengthen the neck of the joystick. This part currently appears weak and may not last as long as we would like.
Figure: TPU Joystick Prototype
The dumbbell slider side provided similar difficulty to the other side when integrating it into the cube. Once it was in, the dumbbell itself moved easily and the side was fully functional. This side may be updated and reprinted to have the bottom side of the dumbbell shaped as a cylinder instead of a sphere, so that the dumbbell does not wobble so much.
Figure: Dumbbell Slider Prototype
The textured slide printed exactly as we wanted and will not need any design alterations.
Figure: Textured Prototype