Geared stepper retraction problems

Hello everyone,
I have purchased 5:1 geared stepper motor, 0.4A, and i cant get my retraction working at all.
I guess it will have something to do with acceleration etc. When i set my retraction to like 5mm ant 65mm/s, motor just hops back a little, like half of mm retraction of filament. It seems it has no power or can't reach such high speeds/distances.
Can anyone help me to sort this out?
Thanks

A 0.4A motor may need more voltage than you have available to drive it at high speeds unless you are using 24V power. It's more usual to choose motors with rated current in the range 1.2A to 1.7A and these higher current motors need a correspondingly lower voltage.

However, the problem could be that your acceleration is too high, so try reducing it in the firmware configuration.

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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].

65mm/sec may be too fast with a 5:1 gear ratio.
5mm seems a little long unless you're using a bowden tube.

My machine has a 5:1 geared extruder and I get beautiful retraction with acceleration set to 3000mm/sec, speed set to 30 mm/sec, and 0.5-1mm retraction.

Here's what the resulting seams look like:



The tips of the cones are 2mm dia.

Edited 1 time(s). Last edit at 11/06/2015 09:53AM by the_digital_dentist.

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

I am using bowden tube of length about 450-550 mm. I will try to reduce my acceleration settings and increase current a little.

I use bowden too and my stepper motors are rated 2.6A. I use 1800mm/s² for Aemax and 2000mm/s² for retractions.

In marlin configuration.h:

#define DEFAULT_RETRACT_ACCELERATION 2000
#define DEFAULT_MAX_ACCELERATION {1500,1500,20,1800}

Or on LCD (if EEPROM is activated) see in the menu control/motion:
Amax e 1800
A-retract 2000

Retraction length: 5mm
Retraction speed: 65mm/s