Expansion 3HC M906 not working properly

fcwilt

Hi,

~~As I recall the CAN address 121 is the default address for a Duet 1XD expansion board.~~

I should not trust my memory - 121 is for a 1LC.

~~And that board is used for external stepper drivers needing STEP, DIR and ENABLE signals.~~

~~With the external drivers I have used the current is set in the driver itself and not via a M906 command.~~

Frederick

mauriciomartins

@fcwilt Thanks for your reply!
How to set the current in the 3HC itself not using M906?

fcwilt

This post is deleted!

mauriciomartins

I'm not using 1XD I'm using 3HC with 3 integrated drivers...

fcwilt

@mauriciomartins said in Expansion 3HC M906 not working properly:

I'm not using 1XD I'm using 3HC with 3 integrated drivers...

My bad - 121 is the default address for a 1LC - sorry about the confusion - I should not trust to my memory.

In any case for a 3HC a M906 command should work.

Frederick

deckingman

@mauriciomartins Why do you think that the stepper motor current settings are not being applied correctly?

mauriciomartins

@deckingman because it's clear that there's no torque.
I'm using the same type of nema23 in all axis, the 4 Z motors are connected to the 6HC and I can set the current and it's working,
X and Y not, if I replace it with a nema17 just for debugging it works ,but without a strong torque.

fcwilt

@mauriciomartins said in Expansion 3HC M906 not working properly:

because it's clear that there's no torque.

I have a 6HC/3HC setup on my bench which I just started to work with.

I connected one stepper to the 6HC and one to the 3HC.

I made what I believe are the correct entries in config.g.

Both steppers will move with the DWC jog buttons.

The stepper on 3HC has no torque - which is consistent with your experience.

Now to determine why.

Frederick

deckingman

@mauriciomartins Ahh, so the real issue is that your XY motors don't appear to have enough torque. Your configuration file shows that the steps per mm for Z are 4 times higher than for X or Y, so it will effectively have 4 times better gearing - and you have 4 motors for that single axis, yet only one for Y and 2 for X. So comparing the Z axis behaviour to the X and Y axes is hardly fair.

What do you get if you send M906 without any parameters? The console should tell you want the motor currents are.

deckingman

@fcwilt No problems here. I have XY and Z connected to a 3HC expansion board. X and Y are Nema 17s set to 1800mA, Z is a single Nema 23 set to 2300 mA.

mauriciomartins

@deckingman Could you please share your config.g?
Thanks!

mauriciomartins

@fcwilt Thanks for you feedback!
Could you try what @deckingman is suggesting, sending just M906 without parameters to check the motors currents?
Thanks!

fcwilt

@deckingman said in Expansion 3HC M906 not working properly:

@fcwilt No problems here. I have XY and Z connected to a 3HC expansion board. X and Y are Nema 17s set to 1800mA, Z is a single Nema 23 set to 2300 mA.

Interesting. I wonder what the difference will turn out to be.

Frederick

fcwilt

@mauriciomartins said in Expansion 3HC M906 not working properly:

@fcwilt Thanks for you feedback!
Could you try what @deckingman is suggesting, sending just M906 without parameters to check the motors currents?
Thanks!

I rebooted a few times using different M906 values in the config file.

After the reboot I executed M906 from the console and the values reported always matched.

Interesting situation.

Frederick

mauriciomartins

@fcwilt yah, weird behaviour...
Let's try to bring @dc42 to this topic to help us understanding it

deckingman

@mauriciomartins said in Expansion 3HC M906 not working properly:

@deckingman Could you please share your config.g?
Thanks!

I don't how mush use it'll be to you - it's a CoreXYUVAB with a 6 input (that's 6 extruders) mixing hot end. But as you asked......config.g

fcwilt

@mauriciomartins said in Expansion 3HC M906 not working properly:

@fcwilt yah, weird behaviour...
Let's try to bring @dc42 to this topic to help us understanding it

I just returned to my workbench and powered up the boards.

Still no torque from the stepper on the 3HC.

A temp sensor connected to 3HC was reading correctly.

I tried resetting the boards - first M999 B1 and then M999 - no change to the torque.

I cycled power and now the torque was as expected.

I reset the boards again.

The torque was gone and the temp sensor reading was way off.

I cycled power and now the torque was as expected.

It seems to me that a reset using M999 should restore the boards to the same state as cycling power but it doesn't seem to be

Frederick

deckingman

@fcwilt Welcome to my world!

How are you powering the expansion board? Does M122 B1 show anything? All voltages good?

jay_s_uk

@fcwilt how long have you had it?
might be a lazy crystal

deckingman

@jay_s_uk said in Expansion 3HC M906 not working properly:

@fcwilt how long have you had it?
might be a lazy crystal

Good point. Also, crazy things happen with RRF 3.2 which seem to be fixed in RRF3.2.2. (I had extruders running backwards and fixed with a power cycle). So if either of you are using 3.2 upgrade to 3.2.2..