Hello,
I am building a RepRapPro Mendel with a club at my school and we have just finished assembling the printer. We are on the "commissioning" step on the RepRap Wiki page for the Tricolour Mendel, and we have gotten all the axes to move smoothly, except for the E axis.
At the beginning of our tests, the E axis whined and jittered. Without the large gear on the extruder drive (mini-extruder), the small gear turned with jerky motions. With the large gear inserted into the small gear there was no movement at all, only shaking and whining. We interpreted this as being too low of a current setting, so we raised the voltage measurement on the current setting potentiometer to the maximum recommended amount of 0.6V (Referenced Page). Unfortunately, this did nothing to stop the jitter of the motor.
To see if the motor was damaged, we switched the wiring on the X and E stepper drivers so that the extruder's stepper motor would run off of the X stepper driver, and the X motor on the E driver. Under these circumstances, the extruder drive ran smoothly, but the X carriage began to shake about without moving. It was at this point that we assumed that the controller board, a Melzi, was the source of the problem.
There is nothing wrong with the board as far as we can see. All of the screw terminals are soldered on well, and the connections with the stepper motor wires are sound. The board communicates with the computer, heats up the heated bed and the heating block, and runs the X, Y, and Z axes without any faults. It would seem as if the E stepper driver on the Melzi is not functioning correctly. Is there any way that we could test this to be sure? If this is the problem how could we fix it without having to buy a new board?
I have attached a picture of the E stepper driver on the Melzi board. Below is the link to a video of the X axis hooked up to the E stepper driver, showing the jittering movement that I describe. I apologize for the bad word at the end of the video. It is a bit frustrating being so close to printing, yet having to deal with this possibly expensive problem.
Link: http://www.youtube.com/watch?v=B0i8akUpAlU
I am building a RepRapPro Mendel with a club at my school and we have just finished assembling the printer. We are on the "commissioning" step on the RepRap Wiki page for the Tricolour Mendel, and we have gotten all the axes to move smoothly, except for the E axis.
At the beginning of our tests, the E axis whined and jittered. Without the large gear on the extruder drive (mini-extruder), the small gear turned with jerky motions. With the large gear inserted into the small gear there was no movement at all, only shaking and whining. We interpreted this as being too low of a current setting, so we raised the voltage measurement on the current setting potentiometer to the maximum recommended amount of 0.6V (Referenced Page). Unfortunately, this did nothing to stop the jitter of the motor.
To see if the motor was damaged, we switched the wiring on the X and E stepper drivers so that the extruder's stepper motor would run off of the X stepper driver, and the X motor on the E driver. Under these circumstances, the extruder drive ran smoothly, but the X carriage began to shake about without moving. It was at this point that we assumed that the controller board, a Melzi, was the source of the problem.
There is nothing wrong with the board as far as we can see. All of the screw terminals are soldered on well, and the connections with the stepper motor wires are sound. The board communicates with the computer, heats up the heated bed and the heating block, and runs the X, Y, and Z axes without any faults. It would seem as if the E stepper driver on the Melzi is not functioning correctly. Is there any way that we could test this to be sure? If this is the problem how could we fix it without having to buy a new board?
I have attached a picture of the E stepper driver on the Melzi board. Below is the link to a video of the X axis hooked up to the E stepper driver, showing the jittering movement that I describe. I apologize for the bad word at the end of the video. It is a bit frustrating being so close to printing, yet having to deal with this possibly expensive problem.
Link: http://www.youtube.com/watch?v=B0i8akUpAlU