Extruder Motor going crazy?

[wannamaker 0]

Hi,

Can anyone help me...please.

I have recently purchased my Ultimaker and although i have been fiddling, changing, swapping, tweaking and learning for what seems like weeks now and still don't have something you could really call a print..... i love it. I purchased the machine for the challenge and to learn new things - it hasn't let me down - i just wish i could print something. :cry:

My question is to do with the extruder. I have read many threads detailing the importance of getting the right amount of tension and have experienced what happens when you tighten the screw too much or too little. What i don't understand is why my extruder is spinning so much and so fast. This results in the filament being sent, smoothly to the hot end to start with and then lots of slippage and strange noises from the extruder motor there after. I have looked at as many working Ultimaker videos as i can find on YouTube and all seem to have a much slower spinning feeder wheel. Which makes sense to me..... why is mine going so fast?

The motor is very hot in comparison to the other two motors.

I have tried to print a few different files the one shown below is the 20mm box from .....

http://www.thingiverse.com/thing:5573

I have had the same extruder spinning wheel problem each time. I have also tried to print directly from an SD card on my controller.

1,

This first video shows how quickly and how much the wheel is spinning. This is at the start of the print.

 

2,

This one shows it stopping quickly as it is going. This just before the filament stopped coming out of the hot end.

 

3,

This one shows the wheel stalling and making a whining noise. I am fiddling with the wheel which shows there is no resistance.

 

Sorry about the toilet in the background!!!

http://www.thingiverse.com/thing:5573

20mm box

I am printing using Cura (mainly because this is the only program i can print from for various reasons). I am on a windows 7 machine.

These are screen shots from Cura to show settings.

These are my 'prints' so far....

Thanks to anyone who can help

[wannamaker 0]

This is the start of the Gcode file - thought it might help!

;TYPE:CUSTOM

M92 E86588.800000

M109 S215.000000

;Sliced C:UsersBenjaminDesktop20mm-box.stl at: Wed 01 Aug 2012 13:41:42

;Basic settings: Layer height: 0.2 Walls: 0.8 Fill: 20

;Print time: 0:12

;Filament used: 0.34m 2.93g

;Filament cost: Unknown

G21 ;metric values

G90 ;absolute positioning

M107 ;start with the fan off

G28 X0 Y0 ;move X/Y to min endstops

G28 Z0 ;move Z to min endstops

G92 X0 Y0 Z0 E0 ;reset software position to front/left/z=0.0

G1 Z15.0 F180

G92 E0 ;zero the extruded length

G1 F200 E3

G92 E0 ;zero the extruded length again

;G1 X100 Y100 F9000

G1 F9000

;LAYER:0

;TYPE:SKIRT

G1 X78.8 Y118.92 Z0.36 F9000.0

G1 F300.0

G1 E3.0

G1 F9000.0

G1 X119.6 Y118.92 Z0.36 F750.0 E4.9903

G1 X119.6 Y80.28 E6.8753

G1 X78.8 Y80.28 E8.8656

G1 X78.8 Y118.92 E10.7506

G1 X79.2 Y118.52 F9000.0

G1 X119.2 Y118.52 F750.0 E12.7019

G1 X119.2 Y80.68 E14.5478

G1 X79.2 Y80.68 E16.4991

G1 X79.2 Y118.52 E18.345

G1 X83.2 Y84.76 F9000.0

G1 X83.2 Y114.44 F750.0 E19.7929

G1 X84.8 Y114.44 E19.871

G1 X84.8 Y84.76 E21.3188

G1 X86.4 Y84.76 E21.3969

G1 X86.4 Y114.44 E22.8447

G1 X88.0 Y114.44 E22.9228

G1 X88.0 Y84.76 E24.3707

G1 X89.6 Y84.76 E24.4487

G1 X89.6 Y114.44 E25.8966

G1 X91.2 Y114.44 E25.9746

G1 X91.2 Y84.76 E27.4225

G1 X92.8 Y84.76 E27.5005

G1 X92.8 Y114.44 E28.9484

G1 X94.4 Y114.44 E29.0265

G1 X94.4 Y84.76 E30.4743

G1 X96.0 Y84.76 E30.5524

G1 X96.0 Y114.44 E32.0002

G1 X97.6 Y114.44 E32.0783

G1 X97.6 Y84.76 E33.5262

G1 X99.2 Y84.76 E33.6042

G1 X99.2 Y114.44 E35.0521

G1 X100.8 Y114.44 E35.1301

G1 X100.8 Y84.76 E36.578

G1 X102.4 Y84.76 E36.6561

G1 X102.4 Y114.44 E38.1039

G1 X104.0 Y114.44 E38.182

G1 X104.0 Y84.76 E39.6298

G1 X105.6 Y84.76 E39.7079

G1 X105.6 Y114.44 E41.1558

G1 X107.2 Y114.44 E41.2338

G1 X107.2 Y84.76 E42.6817

G1 X108.8 Y84.76 E42.7597

G1 X108.8 Y114.44 E44.2076

G1 X110.4 Y114.44 E44.2856

G1 X110.4 Y84.76 E45.7335

G1 X112.0 Y84.76 E45.8116

G1 X112.0 Y114.44 E47.2594

G1 X113.6 Y114.44 E47.3375

G1 X113.6 Y84.76 E48.7853

G1 X115.2 Y84.76 E48.8634

G1 X115.2 Y114.44 E50.3113

G92 E0

[Daid 306]

M92 E86588.800000

That's not good. That should be M92 E865.888

Check your preferences, the "Steps per E" should have a dot in it, no comma. It explains the insane extruder speed you are getting.

[wannamaker 0]

What a difference a decimal point makes!

Daid.... i cant thank you enough. Thank you, thank you, thank you.

[jcosmo 5]

There is a way you can accidentally get an incorrect value for the steps per E when using the calibration feature of Cura.

If you run it through from the start of the wizard it goes fine the first time, but if you adjust the value and retry the 100mm, adjust and repeat, then it gets confused somehow. Or something like that. I reproduced this a number of times but as I had a workaround I didn't chase it,or report it formally in the Cura repo. Interestingly I think it kept making the number progressively smaller by half, not multiplying by 100