Eggbot Troubleshooting
From Evil Mad Scientist Wiki
Don't panic -- there are some first time setup issues you may encounter as well as some other, easily corrected "learning curve" items.
- Stair steps in plotted lines, jerky pen or egg motion
- Loud or whining stepper motors
- Mirrored text
- Upside down text
- Circles plot like ellipses
- Closed figures plot open, the ends do not meet in my plots
- Stair steps
- Loud stepper motors
- Does your plot appear to have "stair steps" or jagged lines? Are the stepper motors loud or whining? You likely need to adjust the "Current Adjust" control on the EBB board with a small screwdriver. This is a physical control -- a potentiometer -- on the EBB circuit board mounted to your Eggbot chassis. The control is labelled "CUR ADJ" on the board. If the current is too strong or too weak you may see (or hear) these symptoms. The current increases as you rotate the control counter-clockwise (CCW). Starting with the control turned all the way clockwise (CW), both motors should be very weak. As you increase the current -- turning the control with a small screw driver CCW -- you should be able to feel the motors increasingly resist moving by your hand. The ideal setting is one that provides smooth, relatively low-noise moves from the stepper motors, but has enough torque that the pen arm is not "floppy". Often, this is about half way CCW, maybe a little less. More current, while increasing the motors torque, leads to jerky moves, with position errors (e.g., stair steps).
- NOTE: the stepper motors are the two large, metal encased motors which mount to the Eggbot's chassis. One rotates the egg while the other rotates the proximal pen arm. The smaller, plastic encased motor which raises and lowers the distal pen arm is a "servo motor". It's behavior is not controlled by the current adjustment.
