Extruder Motor wont stop turning when testing in Pronterface

Hi Everyone,

I have been slowly but surely putting together my Prusa Mendel Build, and have reached the point of testing my Electronics.

I Am Using RAMPs 1.4, connected to an Arduino Clone ATMega2560.
I Am Using an ASUS Laptop Running Windows 7 64bit.
I am Using Pronterface with everything set to default.

My X, Y and Z Axis' all work normally, and the mechanical endstops do their job properly; However, when I test the Extruder, the motor just keeps turning indefinitely without stopping, I have to remove power from everything and usually disconnect and reconnect the motor as well to stop it from moving.

I have tried connecting one of the other motors to the Extruder connection on the board, and the same thing happens on that motor as well. The stepper motor driver seems to work, as it allows me to adjust the trimpot and the motor responds accordingly. But I have not yet tested with another Stepper Motor Driver.

If someone could make sense of my dilemma I would be incredibly greatful.
If this has been answered by another post I would be happy to look there (I did a quick search but did not seem to return any hits on my keywords)

Thank you
-Jaramaniac

Edited 2 time(s). Last edit at 08/18/2012 09:37AM by Jaramaniac.

Perhaps the E step pin is floating and picking up noise. Does it move at a steady speed or is it random?

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[www.hydraraptor.blogspot.com]

Yes, It moves at a very steady pace.

It was a little erratic at first, but I had adjusted the stepper motor driver, and then it would move at a constant rate but would not stop.

Is pronterface able to influence the speed and direction?

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[www.hydraraptor.blogspot.com]

the only value it seems to allow me to change is the amount of Plastic to feed in mm (A)
But here is the list of options that can be adjusted in Pronterface (B ) which I have not changed at all as of yet.

****UPDATE****

I have swapped the stepper motor drivers for my extruder motor and my X axis and tested again.
The X axis still moved as expected and with no issues, but still the same problem with the extruder, So i feel confident at this point that the Stepper Motor Driver is ok (phew!)

The extruder motor remains idle until i send the command to feed some plastic filament (currently set to 4mm)
it then continues to turn the motor clockwise at a slow but steady pace ( I estimate roughly 45seconds - 1minute to complete 1 revolution) until I turn off the power to the RAMPS board.

its currently 11:30pm down here in Queensland, So I'm going to hit the sack.
Here is a link to a photo of my Build on the off chance anyone is interested

Prusa Mendel & Converted PC Power Supply

The interface in pronterface is confusing. The number next to the reverse button is actually the extruder speed, not how far it reverses. So you are telling it to extrude 5mm at 2mm / minute which will take 2.5 minutes. Have you waited that long for it to stop?

60 mm/m is a more reasonable value for the speed.

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[www.hydraraptor.blogspot.com]

Thank you very much hophead.

I had not realised this, I thought the value next the the button was how much it would feed, rather than a feed rate.
I will test again using your suggested values, and see if it corrects my problem, tonight.

Kind Regards

Jaramaniac

****FIXED*****

Huge Thanks to nophead!

Tested the software again, I feel a little silly now, looking at the interface again, I realise now that the value next to reverse, was not the setting for reverse but the feed rate.

Set to 60mm/min and testing instructing it to feed 40mm of plastic, everything worked like clockwork!.

now to work out how to calibrate, and look at trying my first print!!