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Not working steppers on K40-IV

Added by acubino over 8 years ago

Hi.

From a long waiting, i receive my laos board today.

I solder all components, and use the test firmware, but steppers do not move. But really i didn't know very well the testing program

LaOS Test program
++++++++++++++++
Use these keys to test functionality
xX: X Step/Dir yY: Y Step/Dir zZ: Z Step/Dir tT: Ext Step/Dir
e: Toggle Stepper enable
s: SD-Card
i: I2C
1/2/3/4: Outputs

Y press X or x and anyone move on it.
Test x: xstep is now ON
xhome=1, yhome=1, zmin=1, zmax=1
Test x: xstep is now OFF
xhome=1, yhome=1, zmin=1, zmax=1
Test x: xstep is now ON
xhome=1, yhome=1, zmin=1, zmax=1
Test x: xstep is now OFF
xhome=1, yhome=1, zmin=1, zmax=1
Test x: xstep is now ON
xhome=1, yhome=1, zmin=1, zmax=1
Test x: xstep is now OFF
xhome=1, yhome=1, zmin=1, zmax=1
Test x: xstep is now ON
xhome=1, yhome=1, zmin=1, zmax=1
Test x: xstep is now OFF
xhome=1, yhome=1, zmin=1, zmax=1
Test x: xstep is now ON
xhome=1, yhome=1, zmin=1, zmax=1

I connect flatcable on P1 (like a original moshi board) and the Y near to the Polulu. I make short-circuit on Polulu board and use 5V 4A estabiliced power supply.

Any help?

Thanks, Amador.


Replies (12)

RE: Not working steppers on K40-IV - Added by acubino over 8 years ago

I forgot to tell that my 65HVD251 is not on the package (or I lost in my lab) and is not installed. This can be the problem?, I lost it or is optional?

RE: Not working steppers on K40-IV - Added by peter over 8 years ago

The 65HVD.. is optional.

Can you post some pictures, and do some measurements on the pololu pins (motor voltage, enable signal, step/dir signals?)

By the way: Did you press 'e' to enable your motors first? Do you feel friction on the motors?

RE: Not working steppers on K40-IV - Added by jaap over 8 years ago

Something is wrong with the way you connect power to the board.

You are connecting +5V to the connector next to the RJ45 plug. But no power to VMOT, as far as I can see. VMOT (lower right corner in your picture) is the power that the Pololu's use to drive the steppers.

I think you have pulse power on the Pololu's, but no output power.

Most people use a three-way plug (Green Phoenix, should be in the bag of parts) to connect the power from the laser power supply to the board. That plug usually has +5V, 0V and +12/+24V for VMOT.

About the 65HVD251: it's not in the standard set, it's an optional extension.

RE: Not working steppers on K40-IV - Added by acubino over 8 years ago

Yes, i forgot to connect the VMOT.

But i don't understand, what current require VMOT?, original moshi power are 24V (i remove from the panel, but I can put another time). Steppers work with 12V or with 24V or need to check what is the current for the steppers?

RE: Not working steppers on K40-IV - Added by jaap over 8 years ago

VMOT requires the voltage your steppers need. So if they were connected to 24V on the original board, you can use that same power source here. Pololu steppers support up 8 to 35V.

RE: Not working steppers on K40-IV - Added by acubino over 8 years ago

Hi.

I connected original power supply 24V to Vmot, and the 7805 for use 24V for supply board. I check MBED voltaje and are 5V.

I open the test firmware, and press E. Motor on X axis can't be moved (by pressing E), but motor on Y axis any change. I press E, X, x, Y, y but no changes on the motors.
I hear some noisy on the steppers but not all time.
LaOS Test program
++++++++++++++++
Use these keys to test functionality
xX: X Step/Dir yY: Y Step/Dir zZ: Z Step/Dir tT: Ext Step/Dir
e: Toggle Stepper enable
s: SD-Card
i: I2C
1/2/3/4: Outputs
Test e: enable is now ON
xhome=1, yhome=1, zmin=1, zmax=1
Test e: enable is now OFF
xhome=1, yhome=1, zmin=1, zmax=1
Test x: xstep is now ON
xhome=1, yhome=1, zmin=1, zmax=1
Test X: xdir is now ON
xhome=1, yhome=1, zmin=1, zmax=1
Test Y: ydir is now ON
xhome=1, yhome=1, zmin=1, zmax=1
Test y: ystep is now ON
xhome=1, yhome=1, zmin=1, zmax=1

No move but friction change.

RE: Not working steppers on K40-IV - Added by acubino over 8 years ago

Y axis is connected using original cable (like first picture), and X axis is connected using P1 flatcable with the limits.

RE: Not working steppers on K40-IV - Added by jaap over 8 years ago

I think that using the 7805 to go from 24v to 5v is not a good idea, the 7805 will probably get very hot.
You could use a switching power supply replacement for the 7805, or another 5V source.

If you can move the steppers, press e to enable/disable. If that doesn't work, check the Pololu enable pin with a multimeter.

If you have the steppers enabled, the steppers should move a very tiny bit on each pulse you send. It can be so little that you can hardly see it, but if you toggle x/y many times, you should feel the axis move.

Did you solder the micro-stepping pads?

RE: Not working steppers on K40-IV - Added by acubino over 8 years ago

Hi.

I change and add 5V power supply instead of 24V with 7805 (when I make the change I check I can use the 5V line on laser power supply)

I check finally that really steppers are working OK, but the move is too small I didn't see it, also I connect in reverse the flex of P1. Test are OK.

I upload the firmware file (laoslaser-29-12-2012.bin) and the config.txt offered in K40-III (i only change the IP and netmask).
When I start the system, its appear reboots. Power on, steppers feel friction, can't move, main blue led on MBED on. But around 10 seconds, leds poweroff and poweron and start another time, this all times. I try to send a job with visicut with no moves.

Also, I didn't put the jumpers for the Sensor, because i don't understand very well (because my bad english) where I need to put.
VSensors->5V
VEndstops->5V
By the way, I think need to put some wires, but really i didn't know how pins need to make this. Are 4 pins near J43 and 3 pins near the other (VCPU, Vsensors and 5V).

What are doing wrong for now?

I attach you two pictures for the board.

RE: Not working steppers on K40-IV - Added by parag0n over 8 years ago

These are the exact same symptoms i was having with my K40-III. The error turned out to be twofold:
  • a power issue, which i fixed by replacing the 7805 with a switching regulator
  • my i2c board wasnt connected properly, so i recrimped it and shielded the wire

Hope that helps.

RE: Not working steppers on K40-IV - Added by acubino over 8 years ago

Hi

I remove the 7805 (but the pictures was taken before) and use 5v 4A regulated power supply. About i2c i don't have any connected because lcd is out of stock when i buy.

RE: Not working steppers on K40-IV - Added by acubino over 8 years ago

1 more Laos machine working!.

Problem for reboot are I2C is enable (but i didn't have i2c display) I disable this and work Ok with Visicut.

At final of day I make to work PWM and put beautifull the items into the box. For make work PWM is use 1K ressitor between IN and 5V of laser power supply. I use 1K ressitor because the analog input put 1K. In another post I see some users use 1250 ressistor, but I think is because have different configuration.
At 100% (now 0% need to check config) laser use around 25 mA (total are 30 mA). I forgot to check the current at max with analog system, but I think is the same.

Tomorrow more testing and Cups. I will upload pictures and I will update the wiki with some usefull info for moshi or K40 users.

:)

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