Extruder stuttering [SOLVED]

Ever since I started printing, I've notice that the extruder sometimes stutters. It's now got a lot worse. On the piece I'm now printing, it's got a lot worse. Nearly half the time when it is printing, the extruder is not rotating, it's stuttering. The head still appears to be extruding even while this is happening. It's as if the firmware is trying to feed filament to the head much faster than it wants. I've checked that I have the right settings in slic3r in slic3r (filament diameter 1.75mm, extrusion multiplier 1, nozzle diameter 0.5mm). I'm using slic3r 1.0 RC2. My config.g file includes the command M92 E420, because when I calibrated it, exactly 100mm of filament was fed when I asked it to.

Has anyone else seen this? Can someone confirm that 0.5mm is the correct nozzle diameter setting?

Edited 1 time(s). Last edit at 12/30/2013 02:13PM 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].

The only time I had a stuttering extruder motor was when either the filament feed was blocked by debris or the nozzle/ tube junction was not accurate (ptfe tube).
You could also check if the hobbed nut and the bearings are in the right position or if there is any debris in the filament feed.

I wouldn't continue printing even when my extruder motor only stutters for a short amount of time. Risk of damaging the parts is very high. But that's only my two cents.

Markus

---

XBee & electronics blog: [lookmanowire.blogspot.com]

Could it possibly be Extruder motor or its connections? I had a kind of stutter with the Y-axis missing steps. After checking the mechanical smoothness I swapped the motor (with the extruder ironically) and it sorted the Y completely. I can't work out what could cause a stepper motor to be so flakey - but it seems it was.

---

RS Components Reprap Ormerod No. 481

I think I found the immediate cause of the problem. The Z axis is not going up the correct distance between layers. The Ethernet interface said it was at 5.75mm but it was nothing like as high as that, more like 2mm. Now I just need to find out why that was.

---

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].

Hmm... sounds like missed steps to me. Did you play with the acceleration or max axis speeds?

Ian
RepRapPro tech support

Quote
droftarts
Hmm... sounds like missed steps to me. Did you play with the acceleration or max axis speeds?

Ian
RepRapPro tech support

Yes I did. The command you suggested was this:

Quote

Maximum feedrates (mm/s):
M203 X500.00 Y500.00 Z5.00 E45.00

But when I tried that, the printer wouldn't run setbed. I looked at the firmware source and found this:

Quote

case 203: // Set maximum feedrates
for(int8_t drive = 0; drive < DRIVES; drive++)
{
if(gb->Seen(gCodeLetters[drive]))
{
value = gb->GetFValue()*distanceScale*0.016666667; // G Code feedrates are in mm/minute; we need mm/sec;
platform->SetMaxFeedrate(drive, value);
}
}
break;

So I multiplied all the figures by 60. Except that I decided to leave the X, Y and Z max speeds at the defaults of 50, 50 and 3, so I used this:

M203 X3000 Y3000 Z180 E2700

I've removed that line, and the problem has gone away.

---

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].

Hmm... okay, something going wrong there. I'll find out what.

Ian
RepRapPro tech support

Quote
dc42
I think I found the immediate cause of the problem. The Z axis is not going up the correct distance between layers. The Ethernet interface said it was at 5.75mm but it was nothing like as high as that, more like 2mm. Now I just need to find out why that was.

The same problem for me :-(

During my last print the extruded gears starting slipping/stuttering about 5 minutes into the print .
It lasted , on and off , for about 5 minutes. The print quality of this item was incredible from start to finish .

I wondered if it was a filament issue ? .

As I said the print turned out incredible.

H

Ian, that setting may have had nothing to do with the problem after all. Although removing the line appeared to fix the issue, the same thing happened again a few hours later, this time 50mm up the print instead of at the start.

The original z-driven gear was eccentric, so I had replaced it with my own printed part. It turned out that my replacement was a little stiff at one point in the rotation, and I think that is what was causing the z-stepper to slip. I've now reinstated the original gear until I can make one that isn't so tight.

Edited 1 time(s). Last edit at 12/30/2013 04:30PM 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].