How to check Motors health

Hi, I've been continuing to build the little beast here...
I've come to test electronics and wired things, though I keep hearing the motors screaming (yes I know it might be normal - supposedly that'd be a ready state, isn't it?), but they're not moving. Both when turning on the electronics (shouldn't they move a bit when it happens?) or issuing the home command (or any other) to move them.

The electronics i'm using are gen6 and motors nema17 (both from mendel parts).
I suspect the motors aren't broken (or unless, they wouldn't make that noise right?) also because when I turn everything on and they go in still position, i can feel, by trying to pull on the belts, that they're holding it.
Even if, X holds the belt, Y does not. Didn't try Z or EXTR for practical reasons.

Might be about configuring the electronics? I read there are those screws for the motors up there.
Otherwise, how can I know if a motor is correctly working and not broken?
It could also be a PC problem of mine, but I'm still curious in a procedure to check motors and see if they're all right.

sounds like you motor currents are too high => screaming

sounds like your end stops may not be working => no movement when homing because it thinks it is against the endstop.

OK, I'll try to see how to adjust the current there...
So as long as I stick something in the endstop (if as you suggest works in negative logic), it should move, right?

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So as long as I stick something in the endstop (if as you suggest works in negative logic), it should move, right?

For initial testing, yes. For more than that, you want to swap the ...INVERTED... flag in the firmware configuration.

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

I've adjusted (or so i think) the current.
Watched at the datasheets (downloaded from mendelparts too to see differences) saying it wants 2.8V & 1.65A.
I've also read the gen6 page on the wiki, and recognized the ratio (0.57)
I've moved the screws there, and the noise seemed to get higher in pitch and barely recognizable (not sure if it would be right, but i happen to be able to hear my ethernet cable when sends data...)

Stuck something in the endstop, even made a test with it unplugged, but no motion yet.

The board seem ok (I measured the voltage with a multimeter in the test spots for the screw, so I doubt it would sense volts otherwise).

The motors just never moved.

I'm wondering now it the colors are allright or not. In the wiki page of the stepper motors, there's a slight contradiction about them.
It says "Red (actually is Green - see datasheet)". Why not just write green if it's the right one? Do variations of the motor exist?
Since in the datasheets the color were paired, I've connected them as black, green, red, blue. Starting from pin1.

Though, when turning on the board i hear (acoustically) the motor giving a single hit (with no movement).

Edit: sticking something into the endstop changes the pitch sound of the motor, something is happening inside there...

Edited 1 time(s). Last edit at 06/27/2011 02:21PM by Kiantis.

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I'm wondering now it the colors are allright or not. In the wiki page of the stepper motors, there's a slight contradiction about them.

The colors of the wires are unreliable. You have to test that with an ohm-meter.

Of all the 6 possible pairs if wires, two pairs have a low resistance (1.7 ohms in your case). All other pairs have very high resistance ( > 1 Mohms).

Put one of the pairs to the left two pins of the motor connector, the other pair to the right two pins. It doesn't matter, which wire of a pair goes to which of the two pins. The motor should move, then.

If the motor moves in the wrong direction, swap the pins of one pair.

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

If you haven't got a meter just short a random pair of wires until you find one that makes the motor much harder to turn. That is one coil and the other two wires are the other coil. Shorting a pair of wires that are on opposite coils has no effect.

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[www.hydraraptor.blogspot.com]

Thanks for the help, i finally got to make two motors turn...

Sadly though, when i went to the Z axis, things started falling apart. [will open another post about this since the context become different]

Two of the motors (X and Y) seems to get into sensible high heat, but I tried to vary the regulations of current there and didn't seem to change the bahavior much.

If it's overheating what does mean? Too much current?
But if it screams what's meaning? Too low?

I had trouble with my Z motor also. It was the speed setting for the Z motor. I was using repsnapper software and the built-in setting was 50(min) to 150 (max), and my Z motor would buzz and vibrate when I tried to make it move. I changed that to 40(min) and 50 (max) and then it worked fine. Perhaps I can set it higher than that, but I haven't experimented with that yet.

If your motors are getting hot (uncomfortable to touch) then your current is set too high. If you must set it high to get it to move, then perhaps you have too much friction somewhere. If the motors get very hot, it can cause the magnets in the motors to lose strength.

My X and Y motors will make a noise when I first turn on 12V power and then when the controller board (powered by USB ) finishes booting up, the noise will stop.

As to the endstops... If the endstop is disconnected, or if something is blocking the endstop, then the motor will only move one direction, but not the other direction. You should always be able to move one direction even if the endstop is blocked.