Rambo 1.3 board extruder motor stutter

I just got my new RAMBO 1.3L board on Christmas Eve (thanks UltiMaker), and got it hooked up yesterday and extruding fine. Today finalized all the homing aspects and started my first print. That is when noticed that the extruder wasn't extruding, hence start of debug. Had it tentatively working with another Rambo board, though broke USB connector due to my carelessness.

As not sure exactly what firmware already on board other than what's returned from Pronterface (Marlin 1.0.0), downloaded new version of Marlin (1.1 RC3 [github.com]) and modified according to this article:
[reprap.org]

Found this post (http://forums.reprap.org/read.php?262,600615) where extruder exhibited similar problems and did what they did to no effect. Even swapped all of the wires around (black and red, blue and green) in differing combinations to no avail.

Modified firmware to up the voltages, still to no avail. This is what I changed for the voltages:
//#define DIGIPOT_MOTOR_CURRENT {135,135,135,135,135} // Values 0-255 (RAMBO 135 = ~0.75A, 185 = ~1A)
#define DIGIPOT_MOTOR_CURRENT {200,200,200,200,200} // Values 0-255 (RAMBO 135 = ~0.75A, 185 = ~1A)

Motor still stutters. When swapped with X axis the extruder motor ran fine, and the X axis stuttered. Does this mean there's a problem with the board?

Unsure what else to check. Some settings I can tell are different (either I changed or were defaulted):
#define BAUDRATE 250000
#ifndef MOTHERBOARD
#define MOTHERBOARD 301
#endif
//Changed max limits for RigidBot BIG (taken from [github.com])
#define X_MAX_POS 406
#define Y_MAX_POS 304
#define Z_MAX_POS 254

Hardware:
Extruder motor: [store.quintessentialuniversalbuildingdevice.com]
-- Have extruder from them too, yet don't see it listed anymore, it's their MBE v9
-- 24V extruder fan
RigidBot Big with Rambo 1.3 board [ultimachine.com]
-- RigidBot branded stepper motors for all axis
24V power supply Meanwell SE-600-24 [www.mouser.com]

As don't have original source sketch from UltiMaker can't truly tell what's different and what's not. Any help is appreciated.

After sleeping on this for one night, decided to do a snails pace through the code (Marlin 1.1 RC3) looking for anything extruder related. Found this:
#define INVERT_E0_DIR false // for direct drive extruder v9 set to true, for geared extruder set to false

As this extruder is direct drive set this to be like the following:
#define INVERT_E0_DIR true // for direct drive extruder v9 set to true, for geared extruder set to false

Oddly, or not, enough is that the X axis is also set to true, which was a first go to to test if something is wrong with the motor and/or board.

For now it seems to work. Will put everything back together, do couple tests, and report back.

Am slightly baffled and not quite sure what to think, whether it doesn't like me, some hardware / software thing is wonky, or if the moons and stars are out of alignment.

Switched the extruder pins and, while disassembled, everything worked super. Soon as put shroud on covering the center spindle of extruder motor and loosely attached the bolts, it went back to the jittery motion. When removed shroud to like it was, jittery motion remained so didn't seem like tension on the motor caused it. One item of note is had to change INVERT_E0_DIR back to false as motor moved in wrong direction when setup on second extruder pins. I doubt this is the cause of my heartache.

Current settings in Marlin 1.1 RC3 code:
//Swap these as a test (E0 and E1)
#define E1_STEP_PIN 34
#define E1_DIR_PIN 43
#define E1_ENABLE_PIN 26
#define E1_MS1_PIN 65
#define E1_MS2_PIN 66

#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 INVERT_E0_DIR false // for direct drive extruder v9 set to true, for geared extruder set to false
#define INVERT_E1_DIR false // for direct drive extruder v9 set to true, for geared extruder set to false

Would it be best to get a whole different extruder assemble (everything) and change all of that, change stepper motor out, or do something else? Am starting to get upset and want to put this behind me for next challenge in this challenging project.

Edit: 12/27/2015 15:42 PST
Plugged in an old stepper motor I had for my MakerFlop CupCake back when had it working. Sticker on back says it's model 4218L-01-10, and a quick search says it's from Lin Engineering. This is the datasheet I found: [wiki.laglab.org]. This stepper worked great when plugged in. When I let it sit for a minute or two it exhibited the same behavior of jiggling. Am at a loss as to cause other than contacting UltiMachine to see if they're had reports of this same thing. Maybe board is installed wrong, really have no idea at this point.

Edited 2 time(s). Last edit at 12/27/2015 06:48PM by kutch2001.

I have a couple additional questions.

Since have received no responses, not even best guesses, am I in the proper place to ask such a question. If not the proper place where should I ask?

If I am in the proper place, is there a different way should phrase the question?

Currently able to extrude outside of print mode fine, by upping the power sent to the extruder stepper motor. Soon as start the print process it starts the jittery extruder motion, only extruding plastic when filament is pushed down manually, with some force. When lift extruder up 10mm+ can extrude fine, but once start it fails, doesn't even lay the first layer down, not any forward movement at all on the extruder.. ONE very odd note, is when I "fake" the printer thinking it's lowered Z axis all the way to build place, get great extrusion during build.

DO NOT have active cooling on the board (problem?). No heatsinks on stepper motor chips (on board), issue? Have felt the chips with bare finger and they get quite warm / hot. Could power to board be questionable when print starts? Need to add anything to begin G-code?

Really am drawing a blank....

Received some assistance from Ultimachine (told me to up amps) so will go back to them.

Below is current settings of interest..
//#define DIGIPOT_MOTOR_CURRENT {135,135,135,135,135} // Values 0-255 (RAMBO 135 = ~0.75A, 185 = ~1A)
#define DIGIPOT_MOTOR_CURRENT {140,140,185,185,140} // Values 0-255 (RAMBO 135 = ~0.75A, 185 = ~1A)


Other than this, everything else works super!

What type of extruder do you have, what is its steps/mm, and what is the specification of your extruder drive motor?

Make sure you are not starting the print with the nozzle too low. With the nozzle hot, at Z=0 it should just grip a piece of paper between the nozzle and the bed.

---

Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Thanks for your reply:

Hardware:
Basic Extruder: [store.quintessentialuniversalbuildingdevice.com]
-- using RigidBot extruder hardware (not the motor) [rigidbot.com]
-- 24V extruder fan
-- Motor specs [store.quintessentialuniversalbuildingdevice.com]
Motor Length 40mm
Holding Torque: 4.5kg*cm
Rated Voltage: 7.2v
Step Angle: 1.8 Degrees
Resistance Per Phase 6Ohm
Inductance Per Phase 13mh
Current Per Phase 1.2A
Shaft Diameter: 5mm
4-Wire Red|Blue / Green|Black
-- Steps per mm (in software) - set to 100.0. This moved 10mm filament through extruder pinch gear.
//RK Copied from [github.com]
#define DEFAULT_AXIS_STEPS_PER_UNIT {44.3090,44.3090,1600,100.0}//760*1.1} //z was 400 before new motors // default steps per unit for Rigidbot //22.1545 for 8th ms
#define DEFAULT_MAX_FEEDRATE {500, 500, 4, 25} // (mm/sec)
-- PTFE lined heater barrel (bottom 2/3)
-- 0.4mm nozzle
-- Microstep setting (I'm guessing)
// MS1 MS2 Stepper Driver Microstepping mode table
#define MICROSTEP1 LOW,LOW
#define MICROSTEP2 HIGH,LOW
#define MICROSTEP4 LOW,HIGH
#define MICROSTEP8 HIGH,HIGH
#define MICROSTEP16 HIGH,HIGH

// Microstep setting (Only functional when stepper driver microstep pins are connected to MCU.
#define MICROSTEP_MODES {16,16,16,16,16} // [1,2,4,8,16]

RigidBot Big with Rambo 1.3 board [ultimachine.com]
-- RigidBot branded stepper motors for all axis
24V power supply Meanwell SE-600-24 [www.mouser.com]

There is a visible gap between extruder tip and build plate. So much can easily slide dollar bill (US currency) underneath with ease.

Am using Printrun (Pronterface), and from a cold start (preheated build plate to 57C), tried printing a 15mm cube. Printer did the following steps after starting:
- Wait till build plate temp is 65C
- Home all axis
- Raise nozzle 1cm
- Heat extruder nozzle
- Lower nozzle 1cm
- Move nozzle to center X / Y
- Start extruding
- Build plate temp - 65C, Extruder temp 190C (first layer)

At first extrusion motor started the jiggering motion. This was after printer unplugged from computer, and wall power, for 24 hours (give or take).

Paused print, raised extruder 11 cm and turned off build plate / extruder heat.
Let extruder cool to ~45C, turn it on, waited for temp to stabilize (185C) and extrude 20 mm filament fine.
Turn off extruder again.

QESTION: Could it be beneficial if run thicker wire for extruder motor? Less resistance? Did extend wire a little, with new total length of approximately 48 inches (about 122 cm (48 * 25.4)

Edited 1 time(s). Last edit at 01/07/2016 02:32AM by kutch2001.

The extruder motor cabling is unlikely to be a problem, unless you have a bad connection in it somewhere (most likely in a crimp connector).

If the driver chips (in particular, the extruder driver chips) only get warm, that's OK. If they get too hot to touch, then they may need cooling, but not necessarily.

When you swapped the motor with the X axis and the problem moved to the Z axis, do you mean that you physically swapped the motors over, and the problem moved to the X axis? If so, that indicates a problem with the motor. Check that it turns freely, and if it gets stuck sometimes, dismantle it and remove any debris.

If you mean you swapped the extruder and X motor connections over on the electronics, and the problem moved to the X axis, that suggests a problem with the extruder output driver chip. If the RAMBO board has a second extruder output, try driving the extruder motor from that instead, with appropriate firmware configuration changes.

Never connect or disconnect motors to the electronics with power applied, as doing so may damage the driver chips.

Edited 2 time(s). Last edit at 01/07/2016 03:48AM by dc42.

---

Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Thanks Dc42

I did swap the connectors on the electronics after issued an M84 command (to turn off stepper motors) and did not physically change motors around.

I also changed from Extruder 0 to extruder 1, in firmware as well as the connector, and the problem reappeared.

All motors turn freely and am careful to issue M84 before touching any of the stepper motor wiring.

The chips do get HOT to the touch, almost immediately hot after start the motor. Guess it couldn't hurt to add some heatsinks to the board. Chip is 5mm x 5mm so am sure an oversized one would work.

Judging by all this, it almost seems like the board might be suspect. Will validate the wiring and make sure it's solid as strange this only happens when extruder is at lowest point. There is plenty of slack in the line. Will solder the wiring extension in place to verify. Had to extend wires for thermistor and heater too and those work fine. All done in same manner.

Will update tonight.

--RESOLVED--

It appears to have been a loose wire. When took the extension wires apart and soldered them back together there were no problems at all. Am assuming they separater just enough, when extruder was at bottom, that it caused no contact to be made. While 10mm above that they connected back.

Thank you dc42 for the assistance in helping me resolve this.

Moral of the story:
An ounce of solder is worth several hours / days of aggravation.

I'm glad you solved it. Do not use stick on heatsinks with the drivers on the RAMBO, they are more likely to make the cooling worse IMO. If you are worried about the driver temperatures, use a 40mm fan to blow air lengthways over both sides of the board.

Edited 1 time(s). Last edit at 01/09/2016 03:00AM by dc42.

---

Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Thanks again, will use your advice and stay away from the stick ons.

When put power supply under the heated bed, going to route the exhaust of it over the board. Don't have board elevated right now, though will remedy that.

Hi, I seem to be having a similar problem. Could your clarify what your solution was please?

I read through the whole thing and I am baffled my self. I lost power while on a laptop in the middle of a print and everything went to hell from there on. Replaced all my driver chips and got x,y,z, working almost perfect. My problem remains on the E0 extruder. It seems like the problem you describe. I have not tried a new motor yet because its a pain to rewire but that is my next step. Will post a solution when I got it going again but thanks for posting this.