Weak Slipping Extruder motor W / Temp fix

Hello All,
My new taz 4 (#2) has been running well up until recently. After having 0 issues printing various objects over the last few weeks it seems the extruder stepper motor is now slipping as it tries to feed filament.

I have checked the security of all the attachment points on my extruder (Hobbled bolt, herringbone gears) and was not able to discover any loose components. When i try to extrude without the hot end attached it still slips. The Torque is currently insufficient to even feed filament into the air?

Any advice and recommendations would be greatly appreciated… As my stepper motor (& entire machine) is new I did not want to believe the stepper motor could already be malfunctioning but i see no other reason for the fault at this time. The motor rotates freely in hand with no binding as well.

I have checked the resistance for each phase on the stepper motor and it indicates 2.8ohms per phase as per the manual. Electrically the motor is fine. Does this mean my control board has died?

Edit #2:

For those with the following problem:

  •   Extruder Stepper motor is no longer providing sufficient torque.

Represented with the following symptoms:

  • The Extruder stepper motor is slipping as it tries to feed filament.
  • The Extruder without the hot end attached still slips while attempting to extrude filament into air.
  • The Extruder motor rotates freely in hand with no binding.
  • The resistance for each phase on the stepper motor indicates 2.8ohms per phase as per the datasheet.
  • The security of all the attachment points on the extruder assembly (Hobbled bolt, herringbone gears) do not have any loose components.

    Your RAMBo control board Extruder port (E0) may have failed as mine did. I have included a temporary fix below in my 3rd post for your reference.

Some further testing has revealed that the Rambo control board may be the culprit. Once I moved the extruder stepper motor to the X axis carriage (plug swap) and commanded an X axis movement from the LCD screen the stepper motor was back to full strength. Any Stepper motor plugged into the Extruder port failed to rotate with any significant torque. I will be contacting customer support for assistance regarding the potentially failed control board :frowning:

(Why do these things always go bad approaching the weekend? :frowning: :frowning: )

On a side note… Does anybody know if it would be possible to power the extruder motor from the E1 port on the rambo board vice the E0 port while i’m awaiting a replacement? I’m sure there would be some sort of firmware change involved but i’d imagine (and possibly incorrectly so) it shouldn’t be terribly hard.

Lastly has anybody else had a similar problem with control board failures?? Could this be related to the known ESD issue?

Way to test that out! The easiest way to damage a stepper motor driver is to unplug it while powered. When you contact support, send in the following information:

  • Order number

  • 3D printer serial number

  • Contact information

  • Shipping information


For those with a similar problem awaiting replacement of your RAMBo control board a temporary fix can be applied to bypass the original failed E0 port on your RAMBo. By opening your electronics enclosure and swapping the extruder 4 pin connector from E0 to E1 and changing the below section of code in the firmware you can utilize the second extruder port until the board is replaced with no other modifications.

NOTE: This temporary work around has been tested to work on the Taz 4 only.

NOTE: This modification requires an understanding of the Arduino programming enviroment and a basic understanding of electronic circuitry. If you are uncomfortable with the concept of opening your electronics enclosure do not attempt to perform this fix without assistance.

NOTE: This modification is intended only for those using a single extruder.

NOTE: This modification was performed to fix the problems listed from my original post.

WARNING: It is important to change the RAMBo control board section only on the Pins.h page as multiple control boards are listed on this page!

In your firmware locate the Pins.h page and under the RAMBo control board section change the following code from

#define E0_STEP_PIN 34
#define E0_DIR_PIN 43
#define E0_ENABLE_PIN 26
#define E0_MS1_PIN 65
#define E0_MS2_PIN 66

#define E1_STEP_PIN 33
#define E1_DIR_PIN 42
#define E1_ENABLE_PIN 25
#define E1_MS1_PIN 63
#define E1_MS2_PIN 64

To this

#define E0_STEP_PIN 33
#define E0_DIR_PIN 42
#define E0_ENABLE_PIN 25
#define E0_MS1_PIN 63
#define E0_MS2_PIN 64

#define E1_STEP_PIN 34
#define E1_DIR_PIN 43
#define E1_ENABLE_PIN 25
#define E1_MS1_PIN 65
#define E1_MS2_PIN 66

Hopefully this helps everybody continue printing while awaiting parts. Those of you utilizing a dual extruder setup will only be able to utilize one extruder until the board can be replaced. Best of luck to all and happy printing!

While this is a temporary fix to a problem I am still investigating the root cause of the original failure. Preventing a repeat failure is equally important to me as fixing the resultant issues.

Great post! Thanks!