Prusa I3 Z motors not moving

Hello everyone,

Just finished assembling my Prusa I3 rework kit (Running Marlin) .

X & Y motors move fine but the 2x Z motors dont move at all.
I disconnected the threaded rod which connects to the Z motors and wrapped some tape around it to see if it spins without any loads and it still doesn't.
Although on Pronterface when I click to move the Z axis I do hear a noise from the Z motors. Its a soft noise and as if its moving very softly between an angle of 45 degrees and back and just repeats the movement.

I tried finding a solution and most people say its to do with the feedrate speeds, but mine are very conservative anyways...

"#define HOMING_FEEDRATE {50*60, 50*60, 4*60, 0} // set the homing speeds (mm/min)

#define DEFAULT_AXIS_STEPS_PER_UNIT {80.5,80,4000,455}
#define DEFAULT_MAX_FEEDRATE {500, 500, 2, 25} // (mm/sec)
#define DEFAULT_MAX_ACCELERATION {9000,9000,100,10000}

#define DEFAULT_ACCELERATION 500
#define DEFAULT_RETRACT_ACCELERATION 500
#define DEFAULT_TRAVEL_ACCELERATION 500


#define DEFAULT_XYJERK 5.0 // (mm/sec)
#define DEFAULT_ZJERK 0.4 // (mm/sec)
#define DEFAULT_EJERK 5.0 // (mm/sec)"

On my pronterface my XY is set to 2500 and Z is set to 3000.



I took out my X motor connection from my Ramps 1.4 and tried putting both the Z motors in (one at a time) then tried moving it and still got the same response as if its making the moving noise but not actually moving.
I put back my X motor and now the X motor wont move aswell

If anyone could suggest ANYTHING I would be very grateful !!

Thanks alot.

Regards,
Erfan

Edited 1 time(s). Last edit at 04/19/2015 10:15PM by erfansafazadeh.

Bump !

Is there anything at all anyone can think of ?!

Are you homing the Z axis before you try moving it? The firmware won't let it move until it has been homed.

You stated that you checked each motor by connecting them to the X axis connector on the Ramps board and it still wouldn't turn? I assume you were using Pronterface to turn the X-axis motor with the Z-axis motor connected to the X-axis connector on the Ramps board.

Are you sure you have the wiring right on the Z axis motors? That's where I would start if the motors won't turn when hooked up to a known good driver connection.

Edited 2 time(s). Last edit at 04/20/2015 01:30PM by psneddon.

As psneddon suggests I would meter the wires on the Z axis motors to check they are correct and not just rely on the colour code.
[reprap.org]

Steve

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My updated Instructable on our Prusa i3 Build
[www.instructables.com]

Quote
Vanbot
Are you homing the Z axis before you try moving it? The firmware won't let it move until it has been homed.

the Z motors arent moving properly at all. I put the Z motor where the X one is connected to and it still didnt move (Even though X moves when its connected)

Quote
psneddon
You stated that you checked each motor by connecting them to the X axis connector on the Ramps board and it still wouldn't turn? I assume you were using Pronterface to turn the X-axis motor with the Z-axis motor connected to the X-axis connector on the Ramps board.

Are you sure you have the wiring right on the Z axis motors? That's where I would start if the motors won't turn when hooked up to a known good driver connection.

I am fairly certain I got the right wiring. All my nema 17 motors came with the wires being connected in a connector (all 5 motors have same colour wiring aswell), but I still tested with my voltmeter and the z motors work in that respect (with voltmeter).

My X and Y move fine just the Z doesnt.

Anything else I should check?

Edited 1 time(s). Last edit at 04/21/2015 09:16PM by erfansafazadeh.

If each of your motors had worked when plugged into the X or Y axis connectors on the Ramps board I would have suspected that one of them was connected wrong/backwards and that they were fighting each other to turn. However, since you stated:

"the Z motors arent moving properly at all. I put the Z motor where the X one is connected to and it still didnt move (Even though X moves when its connected)"

That would lead me to a couple of possibilities

1) motor wiring is incorrect
2) the Z axis motors are bad

I would suspect the wiring myself - search for how to check stepper motors and you'll find how to identify the right pairs of wires that control the stepper motor.

Connect any two leads of the stepper motor together and if they are the correct pair that go together, there should be significant resistance when the motor shaft is turned by hand.

Again, there are numerous threads and youtube videos that cover this.

If you find out what the problem was, please post your solution. Thanks.

Quote
psneddon
If you find out what the problem was, please post your solution. Thanks.

I think there was just an issue with the connectors. For some reason the yellow wire on both my Z stepper motors was pushed up and became lose when I inserted it into their respective slots.

I am still far from the road of having a completed and functional 3d printer
Still having issues with having fluid and working movement on Pronterface. When everything is fully worked out Ill make a detailed post explaining how I corrected the issues!

Thanks for the update. I'm glad you found the problem with the connectors. One problem solved.

So what did you find was the problem of your z motors not turning. I just built an I3 and I am having the same problem. Very frustratin my conectors are fine and I tried using a stepper motor from my other printer and it does the same thing. It makes a noise and jerks but wont turn.

jonbroardfoot, what does this line in your Marlin configuration.h look like?

#define DEFAULT_MAX_FEEDRATE {500, 500, 2, 25} // (mm/sec)

Steve

Hey Steve,


Thanks for responding. This is what mine is set too.

#define DEFAULT_MAX_FEEDRATE {500, 500, 5, 45} // (mm/sec)

Change the 5 to a 2 , upload and try it

I have tried to do that already and I get the same thing. It wants to turn it seems like it is not getting enough power though.

Had same problem. Crank up your Polulu current drivers for a test.

My drivers are all the way up. Is there an easy way to tell how much power is coming out of your drivers. Right now I just play with it. I turn it a quarter turn then try moving it. and repeat that step till it seems it is at its highest setting.

Are you sure the #define DEFAULT_MAX_FEEDRATE for Z axis is set at 2 rather than 5?

Use a voltmeter on 2v DC scale between ground and the driver pot.
Should be around .7v

Steve

---

My updated Instructable on our Prusa i3 Build
[www.instructables.com]