Retraction not working, Marlin and Ramps 1.4

Hi

My setup is not retracting what ever I do. In the marlin menu I try to move the axis E backwards resulting in normal direction move, aka trying to move it what ever direction causes it to move in the positive direction. When printing there is no retraction, it is probably also into the positive direction thus harder to see. I tried to measure the voltage between DIR pin and GND pin on my driver when trying to retract (moving axis E into negative direction in Marlin's menu in my printer), resulting 0 volts.

I have been changing the retract settings in Marlins config file without success.

Here are my movement settings:

//// MOVEMENT SETTINGS
#define NUM_AXIS 4 // The axis order in all axis related arrays is X, Y, Z, E
#define HOMING_FEEDRATE {100*60, 100*60, 3*60, 0} // set the homing speeds (mm/min)

// default settings

#define DEFAULT_AXIS_STEPS_PER_UNIT {40,40,513,120} // default steps per unit for Ultimaker
#define DEFAULT_MAX_FEEDRATE {250, 250, 5, 25} // (mm/sec)
#define DEFAULT_MAX_ACCELERATION {1000,1000,30,10000} // X, Y, Z, E maximum start speed for accelerated moves. E default values are good for Skeinforge 40+, for older versions raise them a lot.

#define DEFAULT_ACCELERATION 1000 // X, Y, Z and E acceleration in mm/s^2 for printing moves
#define DEFAULT_RETRACT_ACCELERATION 1000 // E acceleration in mm/s^2 for retracts
#define DEFAULT_TRAVEL_ACCELERATION 700 // X, Y, Z acceleration in mm/s^2 for travel (non printing) moves

// Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).
// The offset has to be X=0, Y=0 for the extruder 0 hotend (default extruder).
// For the other hotends it is their distance from the extruder 0 hotend.
// #define EXTRUDER_OFFSET_X {0.0, 20.00} // (in mm) for each extruder, offset of the hotend on the X axis
// #define EXTRUDER_OFFSET_Y {0.0, 5.00} // (in mm) for each extruder, offset of the hotend on the Y axis

// The speed change that does not require acceleration (i.e. the software might assume it can be done instantaneously)
#define DEFAULT_XYJERK 20.0 // (mm/sec)
#define DEFAULT_ZJERK 0.4 // (mm/sec)
#define DEFAULT_EJERK 5.0 // (mm/sec)


Any help very much appreciated

Thanks

Edited 2 time(s). Last edit at 08/18/2015 05:56AM by PropellerHat.

I once had a stepper driver which had the DIR pin not working. If you exchange the E stepper driver with e.g. the X driver, will the problem persist, or then appear on the X-axis?

Also, have you checked with an ohmmeter that the connection between the DIR pin of the E0-driver and the Mega pin D28 is good?

Edited 1 time(s). Last edit at 08/18/2015 07:13AM by enif.

I had not checked the connection, but it is 0.4 Ohms.

I also have used several drivers. My initial setup was made with Easy Drivers as the extruder drivers, and I was blaming my prototype boards for this issue. Now I have a DRV8825 directly on the Ramps, and the problem remains.

Edited 1 time(s). Last edit at 08/19/2015 07:39AM by PropellerHat.

Have you verified that your E0_DIR_PIN is indeed set to pin 28?

Have you also checked with the Ohm meter that you don't have a short between D28 and GND (on the Mega *or* the Ramps)?

If all else fails, you can still try to set the E0 pin definitions to the E1 values in your pin definition file

#define E0_STEP_PIN 36
#define E0_DIR_PIN 34
#define E0_ENABLE_PIN 30

and attach driver and motor to the E1 slot...

Edited 1 time(s). Last edit at 08/19/2015 08:16AM by enif.

Does it unretract? Does it make a noise while trying to retract?
Acceleration for e is set to 10000, try 1000.

Hello again. Back to the problem...

When trying to retract, the extruder turns wrong direction aka forward. I have tried also with the FWRetracting on, and then it moves twice forward instead of first retracting and then forwarding. My DRV8825 on the RAMPS has 1.7V between DIR pin and GND pin what ever is happening, was the printer retracting, printing normally or standing idle.

If it's going in the opposite direction you can turn the stepper motor plug around and it will go in the right direction.

This is not a solution. If I turn the polarity of the cabling of the motor then the extruder can only move backwards. That way the printer is completely useless. For me it looks like there is a fault in the direction pin circuitry but I have no other solution than to get a new Mega or Ramps or both that I can't afford. This small voltage in the DIR pin all the time is a wonderous thing. In my other printer the same marlin runs perfect, with a working retraction. In that machine there is 3Drag controller instead of Mega and Ramps.

Edited 2 time(s). Last edit at 09/08/2015 07:55AM by PropellerHat.

Did you try a different stepstick? Or connect the extruder motor to z axis connector? Did you try connecting another stepper motor?
What voltage is on pin 28 or dir e0 pin without stepstick? 1.7 isn't enough to reverse direction, should be at least 2.2v according to the datasheet.

Hi, did you find a solution to this problem? I have exactly same symptoms on same hardware configuration and not sure how to proceed from here. Thanks!