Week 8: Attaching the Servomotor Hub Horn to the Feeder Cover

The feeder cover is the only freely detachable part of the feeder once it is in use. As the only part of the feeder that will rotate freely the cover will need to be attached to the hub horn that rotates once it is fitted onto the servomotor. Initially the cover was attached to the hub horn by means of a ⅝" VELCRO Mini Fastener [1]. One half of the fastener was located on the hub horn, the other on the feeder cover. 

Figure 1. ⅝" VELCRO Mini Fasteners

However on testing the feeder it was discovered that each time the cover rotated, due to the unstable nature of the velcro, the cover experienced a "back-spin" effect. As the feeder is designed to be able to rotate to an exact amount of degrees, this was a problem. The solution was to remove the velcro attachment and attach the hub horn directly to the cover itself. Using hot glue, the hub horn was fixed at the centre of the plexiglass cover. This resulted in more accurate rotations and a more stable structure.

Figure 2. Feeder Cover/Servomotor Hub horn attachment

Week 8: Servomotor/Centre-Piece Assembly

After cutting the circular plexiglass servo support and attaching to the servo itself, it was realised that it would not create a stable enough foundation if we were to create shelf-like extrusions on the inner rounded surface of the centre piece. Another factor was that extra support would be needed to keep the servo elevated without the weight of the servo (and stand) dropping at any given moment in time.

As a result, a second structure was cut from plexiglass; a circular ring with an outer diameter that fits exactly into the inner compartment of the central PVC piece, acting as a stable "shelf". The ring's inner diameter is wide enough to fully support the servomotor stand and allow the connected servo wire to lead to the electrical compartment.

This supporting ring was fixed at a distance of __in from the upper edge of the centre piece. This distance was determined by the height of the servo. Knowing that the servo will be fixed at a certain position while the feeder cover is removed on a day to day basis, the shelf was set at a distance where once the feeder cover is replaced, the feeder is airtight and the cover would be able to rotate freely.


[INSERT PIC]

Measurements:
Inner diameter of plexiglass ring - __in
Outer diameter of plexiglass ring - __in
Distance from upper edge of PVC piece - __in