Different microstepping settings

JamesM

I was looking at whatever information I could find about setting steps and microstepping but I was not able to find an answer to what I'm looking for..I have geared extruders (printed titan and Greg's Wade) and I wanted to lower the microsteps for just the extruder to either 64 or 128 yet keep the x,y & z using the 16 interpolated to 256. Can I do this by just changing the M350 to read M350 X16 Y16 Z16 E128 I1 and make sure I place it after the M92 in my config.g so I don't have to change the step setting?

Thanks for the help.

-James

Phaedrux

In short, yes.

Easiest way is to set stepping to 16 and the steps per mm to be correct for 16. Then after that you can change the microstepping and the firmware will handle the new steps per mm value.

JamesM

Thanks for the reply..so would that mean I have a M350 line followed by the M92 and then another M350?

As in this
M350 X16 Y16 Z16 E16 I0
M92 X80.00 Y80.00 Z400.00 E408.30
M350 X16 Y16 Z16 E128 I1

Phaedrux

@jamesm that's exactly what I do, but your second line only needs the axis that you're modifying. So you'd only need to change E. Also you'd want to have interpolation enabled on the first line.

But really that's just semantics. The way you have it shown will work.

JamesM

@phaedrux I appreciate the input. Once my current print finishes I'll make the change. I'm a big novice with this and it's a bit overwhelming trying to figure stuff out. I just want my retraction speeds to be faster and I stumbled across the spreadsheet for extruder microsteps which shows my max retraction speed would be limited to 1851.9 with 256 microsteps.

Documentation isn't the best and it also doesn't help not knowing what to look for at times.

Phaedrux

Some of the best info is found in the Gcode wiki. If you have any questions about how a g or m code works, the gcode wiki is the first place to look.

https://duet3d.dozuki.com/Wiki/GCode#Section_M350_Set_microstepping_mode

When M350 is processed, the steps/mm will be adjusted automatically to allow for any changes in microstepping. Therefore you can either:

a) Set Steps/mm correctly for the default 1/16 microstepping, then set the microstepping to the desired amount using M350:

M92 X80 Y80 Z400 ; set axis steps/mm
M92 E420:430 ; set extruder 0 and 1 steps/mm
M350 X128 Y128 Z128 E128:128 ; set microstepping
or

b) Set the microstepping using M350 and then set the correct steps/mm for that microstepping amount:

M350 X128 Y128 Z128 E128:128 ; set microstepping
M92 X640 Y640 Z3200 ; set axis steps/mm @128 microstepping
M92 E3360:3440 ; set extruder 0 and 1 steps/mm
Assuming that in the first example the microstepping was initially at the default x16, both the above examples result in the same steps/mm settings.

JamesM

That's the first place I went but it seems to assume someone already has some knowledge.

Phaedrux

I just double checked my own config to make sure what I said was correct. Here's what I use:

M350 X16 Y16 Z16 E16 I1
M92 X200 Y200 Z6400 E805
M350 E64

JamesM

Holy z-steps...LOL.

gnydick

@phaedrux so, the order you issue the commands matter?

It seems weird that the system can get into a state where the config files don't represent the actual config. I'll explain.

If at x16 the steps/mm are 100, then you issue M350 to set it to x64 the system will convert the internal stored value to 400 in memory, but the config file will still say G92 P0 100?

I'm not sure it actually works that way.

When I was changing my micro stepping on my extruder, it didn't work unless I rebooted the controller after M350 and before extruding any filament. If I didn't reboot before calibration, then I would extrude 4x as much filament.

Phaedrux

@jamesm said in Different microstepping settings:

Holy z-steps...LOL.

Hmm, yes. 1mm pitch lead screw, 1.8 degree motor, and geared for more torque.

jaymcd0626

Hi folks, just configuring my Duet 2 Maestro and the M350 line reads like this ;

M350 E8:8:8:8 ;micro-stepping

Not sure how to interpret that.

I have a Lead screw that is 2MM lead / 2 MM pitch. My stepper motor is 1.8 degrees / 200 steps per / rev.

Looking to figure out my M92 ( steps per mm) but I am not sure what the microsteps are set to here. Do I assume 1/8 or ?

thanks

Jay

Phaedrux

Yeah that would be x8 microstepping.

Ideally you would set it to x16 and then set your M92 based on that.

Phaedrux

You can find the relevant formula here to set the steps for the leadscrew axis

https://duet3d.dozuki.com/Wiki/Going_from_Marlin_on_Arduino_to_RepRapFirmware_on_Duet