Ball feeder gate¶
Pinball machines need a mechanism for releasing the balls, so that they can be launched to the board. This mechanism needs to be controlled by the microcontroller, so that it does not release more than one ball to the field at once, and that only set amount of balls per game are released.
I started with a simple design I described previously. I tested them a bit during the output week.
After testing that design a bit, I found out a couple of problems with it:
- It needs a low ceiling, so that the balls will not jump over the gate.
- The hinge gets in the way of the balls, and makes them lift up, giving way for more balls to stack on the gate.
Both of these things could probably be fixed with proper ceiling construction, but fixing the hinge made sense as well. Fixing it was quite easy: I just redrew the whole thing.
Redesign¶
Start with following variables:
| Variable | Value | Description |
|---|---|---|
| ballSize | 13 mm | The diameter of the ball. |
| wallWidth | 7 mm | The thickness of the back wall. |
| hingeDiameter | 5 mm | Diameter for the center hole, where the servo is attached. |
| hingeWall | 1 mm | The wall around the hinge. |
Started a new sketch.
Drew a rectangle with size ballSize*2 by wallWidth + hingeDiameter + 2mm.
Drew a construction line along x-axis. Constrained its midpoint to origin.
Drew a construction line along the wall rect. Set a dimension distance from right edge equal to wallWidth. Constrained its midpoit to origin.
Drew an arc using a center point arc tool starting from origin and going to the left left. Set radius to ballSize + hingeWall + hingeDiameter/2 and angle to 90°.
Connected the bottom end of the arc to the bottom corner of the wall. Connect top end of the arc to the left edge of the wall, along the y-axis.
Extruded it with ballSize.
