Z axis not moving

[Chris Dagher]

Hello, I recently purchased a Replicape, and upon recieving it, I accidentally plugged the positive power lead in to the positive pin of the ext1 slot. (I wasn't thinking) I flashed the Beaglebone with the latest Thing-Image, and all of the motors moved well when I was testing, but after powering off the board, realizing my mistake, and correcting it by plugging the positive power to the positive slot of the power terminal, the Z motor no longer moved. I have tried re-flashing the board with the Kamikaze image as well as the Thing-Image, but it has not worked. The motor locks up and turns approximately one step occasionally, but never more, even when given more commands. I have found that the Z Shift register has the largest connection to the DAC, and I am thinking that the DAC could have been fried. I have traced back all other connections on the .brd file for the A4A, which is the board I have, and this seems to be the only explanation. I just want to get feedback as to what you think, because this has be set back by almost two weeks now.

[Elias Bakken]

Chris, this is an issue I've not seen before. Do you need all the steppers? If not a simple work around is to configure the H-stepper in slave mode and move the Z-motor to this stepper. If you do need the other stepper motor, I think you will have to have scope or at least a multimeter, set all the steppers with the same current and then see if there are any differences between what the DAC values are showing. If you think it is one channel, you should be able to use one of the other free channels. They are broken out on the Expansion header, originally intended for Reach.

[Chris Dagher]

Unfortunately, I do need all of the steppers. Are you saying to slave a motor from the expansion header to another motor? If so, how do I configure the slave configuration? (I already replaced the Z stepper driver myself with my toaster oven turned reflow oven, but haven't tried it yet. Your idea of stepper slaves sounds ore promising.