First Print Problem

Hey,

I just finished the mendel90 kit form nophead today .. did all the testing without problems, levelled the bed and calibrated the extruder and the z home point as good as i could (and uploaded the firmware with the new settings) :-)

Then I wanted to do the first according to the build manual. The printer started to print the outline but nearly at the end of the outline the extruder doesn't work anymore ... the rest of the printer moves just fine (as far as I can tell).
So I stopped the print and tried to check the extruder. I disassembled the extruder a little bit (so the motor shaft is free and not "blocked" by the extruder gear) to check that the motor is spinning like it should but it seems to me that the motor died?!? When I try to extrude/reverse (with cold extrusion override) the motor makes a sound but does not move (looks like the shaft is only "shaking" a little bit).

Now the question, did I really kill the motor and how did I do it? Is there something else that I could check? What did I do wrong?

You probably have a bad connection to the motor. Check that both coils are connected by measuring the resistance between the first two and the second two pins at the Melzi E motor connection. Causes of this problem so far have been bad soldering on the extruder connection PCB or the IDC D type connector not closed properly.

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[www.hydraraptor.blogspot.com]

Hmm.. I just check the resistance on the melzi connectors for all the motors (with the printer turned off). There are all around 2.4 ohm (except the z-motors in series), When i check the e-motor director on the little pcb board connectors i get around 2.2-2.4 ... but I really don't have the best device.

Try swapping the E & Y motor connections at the Melzi to see if the fault stays with the motor, or the Melzi port.

Stepper motors never fail unless you get them so hot the insulation on the wires melts. If the motor vibrates instead of turning only one coil is being driven. That is either wiring, or a Melzi fault but so far on 140 kits faults like this have always turned out to be wiring. It might be an intermittent contact.

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[www.hydraraptor.blogspot.com]

Oh man ... I am soooo f****ing stupid.

I just double checked everything and had a quick look at the configuration.h . Just to notice, that i used "," instead of "." as a decimal point. Changed it to "." and everything works fine.... at least the extruder moves like it should now. Now I have to mount everything back again and try to print

so sorry for wasting anyones time