power off after job?

Hi ppl,

I LinuxCNC n00b. Today I started to configure my machine, and I tested it with LinuxCNC sample code, then I noticed that after running code Axis dont turn off machine , or it's normal behavior ? If yes, there's any way to make it turn off machine after executing a code??

btw, I'm asking this bcoz my motors got REALLY HOT after I run code and exit to eat on another room, they're just there, "paused", but they get 102 oC (checked with IR thermometer).

thanks

What kind of motors are they?
A machine should be able to stay on, holding position, without the motors getting too hot, so it is a bad motor tuning in my point of view.

If you can disconnect the machine after a jog is completed. My guess would that you create a M code that turns off a relay that power the machine. on the end of your code put that M code, then the relay will go off and your motors will not be powered anymore.

Hello,

You did not state what type of motors and drivers you are using, but..

Steppers motors do run hot.
Start by checking that your drivers are set to the proper amps for the motors.
Many drivers have settings to reduce the amps when at idle for a period of time, see if your does and if it set.

You probably do not want to turn the power off to the motors at the end of a job as the power is used to hold the machine in position.


Rick G

Thanks for replies

Rick/emcPT,
I using "classic" chinese AIO 3-axis board (HY-TB4DV-M) with 23KM-C051-07V motors.

Those motors are rated 2A with unipolar wiring (i'm using in bipolar in series - lower current required), and I set dip settings to only 50% (3A rated board - TB6560), fast decay, 1/2 microstep. And I don't think this board have a option to decrease current in idle mode

Anyway, I dont see a problem to turn power off after job on my machine using my setup, since after I hit "power toggle" (software) button on Axis, it just turn off board/stepper without any problem (still don't move any axis)

And I don't think I'll need control a relay to just do that, since just pushing "power" button on Axis (software) it turn off my board (put it on sort kind of idle mode) and motors also shutdown, maybe it's just a conf, or even a M code to push it after completed job


Thanks!

Anyway, I dont see a problem to turn power off after job on my machine

Depending on where your job finished with micro stepping the power may be holding the stepper motors at some position between full steps.
In your case at a half step. With the power off the magnets may pull it to a full step and you do not know which direction it will go. Also without power binding or stress may cause the machine to lose position.

If you are going to re home / touch off after the power was turned off and then on is a different story.

Rick G

candrew wrote:

Thanks for replies


Those motors are rated 2A with unipolar wiring (i'm using in bipolar in series - lower current required), and I set dip settings to only 50% (3A rated board - TB6560), fast decay, 1/2 microstep. And I don't think this board have a option to decrease current in idle mode

!

Are you sure this is correct? It sounds like you may have set the current
50% higher than the rating.

Also, the idle current reduction is a GREAT feature, and helps a lot in
keeping th motors cool.

100C is awfully hot and will probably damage the motors over time.

Jon

In bipolar conf, I calc they work with aprox. 1.6~1.7A current, then 50% of 3A (1.5A) is reasonable.
I checking they right now with 25%... I'll wait 30~60 minutes, to see if they heat, but until now looks like they'll remain only few degrees up room temp. (room temp 29.6 oC - steppers - 32.6 oC). On 50% setiings, they go very fast to 60~65oC....



Anyway, going back to first question, some one known if is possible to toggle software poweroff after a completed job??

Thanks!

Yep... after 1h30, they temp is 36.6~37.0 oC @ 25% current.

LOL stupid chinglish manual.
I checked now with amp meter, now I see,dip settings on manual for 50% and 75% are inverted

On manual:
50% = DIP 1 (OFF) and DIP 2 (ON)
75% = DIP 1 (ON) and DIP 2 (OFF)

But in reality:
50% = DIP 1 (ON) and DIP 2 (OFF)
75% = DIP 1 (OFF) and DIP 2 (ON)

75% @ 3A put them with 2.25A instead 1.5A :/

25% and 100% dip settings on manual are correct (confirmed with amp meter).

update:
After more 1h at (real) 50% my steppers temp stabilized around ~62 oC.

Well, much better than 102 oC and rising...

Another thing about this board, 7812 (regulator for cooling fan) go to ~90 oC with factory heatsink...I changed heatsink of 7805 and 7812 for a little bigger ones which I bought on Tayda Eletronics, and temp of 7812 stabilized at ~67 oC.

Glad to hear you have it sorted out!

Rick G