Printer Errors/Hardware Issues
Printer Only Moves Down
If the bed moves down when you click Z Home and will not move up, verify the connections on for the Z end stop switch on the switch and the board. The connector is easily removed when the case is taken off the Solidoodle.
Extruder Fails Erratically
If the extruder stops working at seemingly random times, it could be due to many different things.
If the filament is left in the extruder for too long while it is hot, the filament can heat up to the point where it degrades and no longer is easy to melt and flow. It is best to keep the extruder off except for when you are printing.
If the tensioning spring is too tight, the hob gear can cut into the filament excessively, digging out a divot which then prevents the filament from feeding any further. When the tension is too high, you will see a build up of filament fragments at the base of the hob gear. Try reducing the tension so that almost none of the tensioning screw is visible (all of it is inside the spring). Make sure that both the hob gear and the pressure bearing are turning. If the bearing does not turn, there may not be enough pressure.
Printer "Skips" in Y (front-to-back) Direction
If you start a print and the printer suddenly starts printing at an offset (front-to-back) from the existing print, then the printer has skipped in the Y direction. This can be caused by:
1) Incorrect belt tension, either too high or too low. Too high tension increases the force required to move the carriage, which can cause the stepper motor to fail to move the carriage successfully. Too low tension can cause the belt to skip over the drive gear. Unfortunately, there is no easy way to measure belt tension, nor is there an accepted "good" level of tension. Look on Thingiverse for Ian's Belt Tension Gauge. Correct belt tension should be about 3.5 mm.
2) Insufficient stepper power. Check that the voltage on the driver daughter board for the Y stepper is correct. There are detailed procedures for this on the Solidoodle web site at the bottom of this page: http://www.solidoodle.com/how-to-2/troubleshooting/
3) Excessive mechanical resistance. If the carriage cannot move freely front-to-back, then the carriage may not position correctly even if the belts are correctly tensioned and the stepper motor has sufficient power. Turn the printer power off and move the carriage front-to-back with your hands. It should move with little resistance, and that resistance should be consistent across the range of motion. If the carriage jams in one part of the range, see if you can find a reason for the increase in resistance. Sometimes, when the front-to-back guide bars are slightly bent, you may need to rotate one or both of those bars to find a position where the carriage moves easily. Once you have rotated the bars into the correct position, you can lock them in place by repositioning the clamps at the end of the bar so that one is maximally clockwise and the other is maximally counterclockwise.