stepper hums but won't move [SOLVED]

[TheHeadlessSourceMan]

I'm excited to finally be about ready to start printing! Trouble is when I try to load fillimet the stepper just hums and no motion.

I tried swapping e0 with x. When I g28 I get y+z and plastic feeding fine. Then I try clicking manual feed and x stepper just hums.

So it has to be some setting or something?? What should I check?

[cambo3d]

double check your wiring maybe?

[mhackney]

That was a good debugging test headless. It tells me that your motor and wiring is most likely correct to each of the 4 motors. You most likely are overdriving the stepper - this is an easy firmware change/fix.

What firmware are you running? What version of the RAMBo do you have? Did you read about 16 micro steps and know what that means and how to configure? Let's start there, and then then next thing to try is lowering the extruder stepper acceleration and speed to 1000 and 60 respectively.

[TheHeadlessSourceMan]

Thanks for your responses!

I'm at work so I don't have the rambo version on me right now, but the code is this one:
https://github.com/johnoly99/Marlin-for ... kmax-rambo
Hopefully that's right.

Doing a diff against the checkout, here are all of my changes (all in Configuration.h)

Synopsis:
I calibrated Kp Ki and Kd
I tried flipping the extruder direction but no difference either way.
I calibrated z home, of course.
And, yes, I doubled the step counts for all four steppers.

Actual complete diff:

Code: Select all

110,112c110,112
<     #define  DEFAULT_Kp 41.49
<     #define  DEFAULT_Ki 2.79 
<     #define  DEFAULT_Kd 154.23 
---
>     #define  DEFAULT_Kp 46.78
>     #define  DEFAULT_Ki 2.68 
>     #define  DEFAULT_Kd 204 
193c193
< #define INVERT_E0_DIR true   // for direct drive extruder v9 set to true, for geared extruder set to false
---
> #define INVERT_E0_DIR false   // for direct drive extruder v9 set to true, for geared extruder set to false
223c223
< #define Z_HOME_POS 374 // Distance between nozzle and print surface after homing.
---
> #define Z_HOME_POS 345.0 // Distance between nozzle and print surface after homing.
231,232c231
< //#define DEFAULT_AXIS_STEPS_PER_UNIT   {53.333, 53.333, 53.333, 292.0}  // default steps per unit for rostockmax
< #define DEFAULT_AXIS_STEPS_PER_UNIT {106.666, 106.666, 106.666, 584.0}
---
> #define DEFAULT_AXIS_STEPS_PER_UNIT   {53.333, 53.333, 53.333, 292.0}  // default steps per unit for rostockmax
306c305
< #endif //__CONFIGURATION_H
---
> #endif //__CONFIGURATION_H

[TheHeadlessSourceMan]

Okay rambo is rev1.1b and there's a sticker also with part number (?) 10000829.

I removed it just to check things out and nothing looks different on e0 from any of the other motor circuits.

[mhackney]

Ok, that version is 16 micro steps. Have you made the required changes in the configuration.h file? If not, you can find them in my build thread. If so, I think you need to crank down the extruder acceleration and speed to 1000 and 50 respectively (to start).

[TheHeadlessSourceMan]

Thanks for the link. Seeing your build would have come in REALLY handy when I was building mine! If I have any friends that build one I'll be sure to direct them there.

But in that thread you mention

Code: Select all

#define MICRO_STEPS 16

I don't have that. That's why I doubled the values in the line

#define DEFAULT_AXIS_STEPS_PER_UNIT {53.333, 53.333, 53.333, 292.0}

Is that not the right thing to do? It seemed to correct the stepping for the x,y,z axes.

[TheHeadlessSourceMan]

Here's another clue:

I was wondering if I just had a bum motor control circuit on my rambo so I switched the plug to E1 and and swapped the values for the extruders at the very bottom of pins.h

Code: Select all

#define E0_STEP_PIN       33//  34
#define E0_DIR_PIN        42//  43
#define E0_ENABLE_PIN   25//    26
#define E0_MS1_PIN 63// 65
#define E0_MS2_PIN 64//66

#define E1_STEP_PIN       34//  33
#define E1_DIR_PIN     43//     42
#define E1_ENABLE_PIN  26//     25
#define E1_MS1_PIN 65//63
#define E1_MS2_PIN 66// 64

It behaved exactly the same way, so at least I know it's not the rambo. It HAS to be software-related somehow... hmmm....

[TheHeadlessSourceMan]

Just by accident I found what's going wrong!

For some reason that I can't explain the first time you tell it to extrude it wants to move the carriage all the way to the top. After that you can issue the command with the carriage anywhere. Weird but whatev.

Anyway, the hum I was hearing just the axis motors churning because the default speed was really, really slow.

Thanks everybody for your help!