(solved) Second Extruder has much too high feed rate

Hi there,

I'm using a Makeblock Constructor 1, which seems to be very near to a mendel 90.

I modified it, to use a dual extruder. All fine, thus far.
Heater is working, (modified configuration on pins, formerly there was a fan configured)
Tempsensor is working. Nice.

The final problem is the extruder-motor itself.

It has a much higher feedrate then extruder0.

When extruding some material with ... for instance ... pronterface, extruder0 puts out material as usual.
When switching to extruder1 with same program-parameters, it presses out lots of material. too much for the nozzle.

I just looked in code, searched for extrudercode, feed rates, but I can't find the right place which needs to be modified.
I checked cables, switched extruder-motor0 with extruder-motor1. So the effect is now on extruder0. That means, that cables and motor are ok, but the firmware is the cause for that.

Could someone help me to find the parameter, which I have to change, so that the second extruder does extract the material as smooth as the first extruder?

Thanks in advance,
Daniel

Edited 1 time(s). Last edit at 06/20/2015 04:58PM by dna.

Firmware is Marlin. I forgot that information.

It sounds to me that the extruder steps/mm is wrong for your second extruder. I don't use Marlin, but my guess is that you may have to change this line in the config file:

#define DEFAULT_AXIS_STEPS_PER_UNIT {80, 80, 80, 663}

to include a 5th value giving the steps/mm for the second extruder drive.

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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].

Hi,

I just changed that. The two extruders are similar.

So I changed:

#define DEFAULT_AXIS_STEPS_PER_UNIT {87.58,87.58,(200.0*16/0.7), 92.65}

to:

#define DEFAULT_AXIS_STEPS_PER_UNIT {87.58,87.58,(200.0*16/0.7), 92.65, 92.65}

Same values for the additional extruder.

I too changed this:

#define NUM_AXIS 5 // The axis order in all axis related arrays is X, Y, Z, E
#define HOMING_FEEDRATE {50*60, 50*60, 2.5*60, 0,0}


Result is the same. :-/

I've done a little more research, and it appears that Marlin uses the same steps/mm value for both extruders. If your electronics has jumpers to select the microstepping factor, are you certain that they are set correctly for the second extruder drive?

---

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].

I'll check this.
Thanks for the hint, I'll be back with the results.

That's it
Wooohooo

jumper Yes/No step size
1 2 3
no no no full step
yes no no half step
no yes no 1/4 step
yes yes no 1/8 step
yes yes yes 1/16 step

All three jumpers were missing. So it moved with full speed.
Now with 1/16, it's as smooth as Extruder0.

Thanks Guys. Without that hint, I would still search within the sources.

Greeitngs, Daniel

Quote
dna

I too changed this:

#define NUM_AXIS 5 // The axis order in all axis related arrays is X, Y, Z, E
#define HOMING_FEEDRATE {50*60, 50*60, 2.5*60, 0,0}


Result is the same. :-/

Just a point here,
Changeing those line will not do anything as the "#" means that they are commented out!

Quote
GRAYWOLF

Quote
dna

I too changed this:

#define NUM_AXIS 5 // The axis order in all axis related arrays is X, Y, Z, E
#define HOMING_FEEDRATE {50*60, 50*60, 2.5*60, 0,0}


Result is the same. :-/

Just a point here,
Changeing those line will not do anything as the "#" means that they are commented out!

Sorry, but commenting stuff in Marlin is "//" the double backlash sign, not "#".
-Olaf

Uh, that's double *forward* slash. Only MacroSquid uses backslashes . . .

- Tim

Quote
tadawson
Uh, that's double *forward* slash. Only MacroSquid uses backslashes . . .

- Tim

My bad, I´m not native english speaking...

Quote
o_lampe

Quote
tadawson
Uh, that's double *forward* slash. Only MacroSquid uses backslashes . . .

- Tim

My bad, I´m not native english speaking...

A lot of folks have been so brainwashed by the MS crap that they think the same thing. . . . and are native english speakers . . . I've even seen street signs with it wrong, it's pretty sad . . . and kind of a pet peeve . . . sorry!

- Tim

You may still find you have slight differences between the two extrude rates. You will need to adjust the extrude rate for the second extruder in your slic3r software. In my case, my second extruder runs about 5% faster than the first, i.e. when the first extruder is calibrated to extrude 50mm when asked, the right hand or second extruder produces about 55mm. In Slic3r, for the filament that you use in the right hand extruder, set the extrusion multiplier at 0.95. So, if you use PLA in both extruders for two colour printing then you will need two Filament definitions, one for the left extruder with an extrusion multiplier of 1.0 and one where you use the filament in the right hand extruder, in my case, using a filament multplier of 0.95.

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Using ABSPrusa Mendel Zaphod with Pronterface and slic3r 1.3.0. Printing well with 3mm PLA and ABS through 2 x J Head Mk IV b and Wade Geared Exruders. Controlled using RAMPS1.4 board running Marlin_v1.1.9