wheatfieldcrows

I have contacted Ultimaker via the support ticket page but haven't heard back. I also pointed them to this forum thread. I rechecked everything and confirmed that the problem is definitely with the x-axis output. The motor, drive train and polulu driver have no effect on the problem. This is what I get when I reset the Arduino: With Marlin Firmware [19] Initializing Serial.[19] Attempting to reset RepRap/Ultimaker (pulsing RTS)[19] Unknown: marlin u0.9.3.1[19] Unknown: sd init fail[19] Ready. With Advised 5D Firmware [20] Initializing Serial.[20] Attempting to reset RepRap/Ultimaker (pulsing RTS)[20] Ready. The problem is similar with each firmware except that I get a few more moves out of the 5D firmware before the motor stops responding. I now note that when I first power up and connect the machine I can issue one to three commands via the x-axis driver and the machine responds. After these initial commands, the motor stops responding. If I then power off the board with the switch, but not unplug the USB cable and power the board back on, the motor will again respond to one to three commands. The whole time the Arduino is connected via the USB cable and ReplicatorG stays connected. I have another Arduino Mega on the way, I figure you can never have too many of those. If that doesn't fix the problem, then it would seem that it is in the Ultimaker board somewhere. This would be supported by the fact that power cycling that board allows me to issue a few commands again. I'll try to contact them about what it would take to get a replacement board. In the meantime, I want to thank everyone for the helpful advice and if anyone has any other ideas I'm all ears. A little frustrating to be so close and yet so far away.

Swapped them and the problem still occurs on the x-axis. I had previously swapped the motors so it appears to be upstream of the polulu driver or between the polulu driver and the motor connector. I unmounted the board and didn't see any abnormal solider joints or traces. I'll attempt to troubleshoot the Arduino later, but other suggestions are much appreciated... Looking forward, if i just buy a new Arduino and install it on the board, and then use ReplicatorG to install the Ultimaker firmware, is that all I have to do to swap Arduinos?

I reset all the resistors by turning the screws all the way left, then all the way right and finally returning to the middle point between the two extremes. The problem still occurred with the x-axis. I then increased the power by turning the x-axis screw slightly right of center, but the x-axis still failed to move every time. I'm going to re-check everything tomorrow and un-mount the board so I can have a look at the connector in detail. Perhaps there is a loose joint. Any other suggestions in the mean time?

After assemblying my Ultimaker I tried to use the control panel to move the print head around. The y-axis and z-axis work great but the x-axis only works intermittently. Sometimes it will only run half of the requested distance, sometimes the print head wont move at all. I tried disconnecting the limit switches to see if it was one of them that was the issue, but still get the intermittent problems. I also tried using different drivers and both a windows and mac to see if it was a software issue. Then I switched the x and y axis cables to see if it was the motor or the controller causing issues. After switching the cables the x-axis motor worked fine and the y-axis motor started having intermittent issues. It would appear that the hardware or firmware is at fault. I was hoping someone might have some insight on further troubleshooting efforts. Also all the stepper motors are warm except for the x-axis motor. Not sure if that is normal.