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Is PID Autotune Still required?

Posted: Sun Mar 24, 2013 6:32 pm
by cassetti
I don't see any settings in Polygonhell's firmware for "Default_Kd" or Ki, or Kp. I have the averages, but what do I do with the values when I have them?

Re: Is PID Autotune Still required?

Posted: Sun Mar 24, 2013 6:57 pm
by cambo3d
update numbers in the eeprom menu

Re: Is PID Autotune Still required?

Posted: Sun Mar 24, 2013 9:22 pm
by cassetti
cambo3d wrote:update numbers in the eeprom menu
But then that means setting the MODE_EEPROM to 1 to activate it. When I activate it, my microsteps revert back to 8!!! Wtf

so again, my question is is the PID autotune required, since apparently you have a choice with the RAMBo 1.1 board - either a working printer with 16 microsteps, or an EEPROM activated rambo with 8 microsteps which attempts to print everything in the middle of the air instead of the build platform

Re: Is PID Autotune Still required?

Posted: Sun Mar 24, 2013 9:45 pm
by cambo3d
that's because your eeprom is set to 8 still,

if you want better temperature stability pid auto tune would be recommended.

Re: Is PID Autotune Still required?

Posted: Sun Mar 24, 2013 10:04 pm
by cassetti
cambo3d wrote:that's because your eeprom is set to 8 still,

if you want better temperature stability pid auto tune would be recommended.
M eeprom has no setting for microsteps - how do I add the ability to edit this setting to the eeprom?

Re: Is PID Autotune Still required?

Posted: Sun Mar 24, 2013 10:23 pm
by mhackney
The firmware CALCULATES the steps per mm for the axis using a number of directives (parameters). The code looks like this:

Code: Select all

// Calculations
#define AXIS_STEPS_PER_MM ((float)(MICRO_STEPS * STEPS_PER_ROTATION) / PULLEY_CIRCUMFERENCE)
#define XAXIS_STEPS_PER_MM AXIS_STEPS_PER_MM
#define YAXIS_STEPS_PER_MM AXIS_STEPS_PER_MM
#define ZAXIS_STEPS_PER_MM AXIS_STEPS_PER_MM
Some of these calculated values are stored in EEPROM. This group should have the standard comment:

Code: Select all

/*Overridden if EEPROM activated. */
but doesn't - if you look down a few lines you will see where these are manually set for Cartesian printers and do have the comment.

The calculated values appear in the EEPROM window in Repetier host (Printer menu->EEPROM Settings) as:

X-axis steps per mm 106.67
y-axis steps per mm 106.67
Z-axis steps per mm 106.67

The calculated values for 16 micro step RAMBo cards (revision 1.1) for the Rostock are 106.67 steps per mm as I showed above. That's what you'll see in the EEPROM, not the number of microsteps. The controller only cares how many microsteps it needs to turn the stepper motor to move a specified distance, that's what "steps per mm" means. To move the X axis 1 mm, you have to tell the stepper to move 106.67 steps.

Re: Is PID Autotune Still required?

Posted: Sun Mar 24, 2013 10:32 pm
by cassetti
Thank you! I saw the steps per mm, but I didn't know if setting that would be the equivalent of setting the microsteps to 16

Re: Is PID Autotune Still required?

Posted: Sun Mar 24, 2013 10:40 pm
by cambo3d
couldn't you just adjust them in eeprom menu in repetier host?

Re: Is PID Autotune Still required?

Posted: Mon Mar 25, 2013 8:00 am
by gsnover
Thanks mHackney! This was really helpful! :D

"The calculated values appear in the EEPROM window in Repetier host (Printer menu->EEPROM Settings) as:

X-axis steps per mm 106.67
y-axis steps per mm 106.67
Z-axis steps per mm 106.67

The calculated values for 16 micro step RAMBo cards (revision 1.1) for the Rostock are 106.67 steps per mm as I showed above. That's what you'll see in the EEPROM, not the number of microsteps. The controller only cares how many microsteps it needs to turn the stepper motor to move a specified distance, that's what "steps per mm" means. To move the X axis 1 mm, you have to tell the stepper to move 106.67 steps."

Re: Is PID Autotune Still required?

Posted: Mon Mar 25, 2013 11:08 am
by cambo3d
gsnover wrote:Thanks mHackney! This was really helpful! :D

"The calculated values appear in the EEPROM window in Repetier host (Printer menu->EEPROM Settings) as:

X-axis steps per mm 106.67
y-axis steps per mm 106.67
Z-axis steps per mm 106.67

The calculated values for 16 micro step RAMBo cards (revision 1.1) for the Rostock are 106.67 steps per mm as I showed above. That's what you'll see in the EEPROM, not the number of microsteps. The controller only cares how many microsteps it needs to turn the stepper motor to move a specified distance, that's what "steps per mm" means. To move the X axis 1 mm, you have to tell the stepper to move 106.67 steps."
dont forget your extruder also..

Re: Is PID Autotune Still required?

Posted: Mon Mar 25, 2013 11:39 am
by mhackney
Yes, the extruder is handled differently. You have to set it explicitly in the Repetier firmware, it does not calculate that. I posted about this in another thread this weekend.

We need to find a better way to enable folks to find this information here. I've posted on this firmware topic at least a dozen times. A search for EEPROM will turn them up. I'm not sure what the best mechanism is though.

Re: Is PID Autotune Still required?

Posted: Mon Mar 25, 2013 11:49 am
by geneb
You might want to write something up and pin it in the Official Docs forum.

g.

Re: Is PID Autotune Still required?

Posted: Mon Mar 25, 2013 5:10 pm
by cassetti
I think there's a few problems with the info available on this forum - one of which is the forum search engine - keywords like extruder are rejected because they are 'too common' - this causes MANY headaches when trying to avoid asking the same question.

Also, I think using the jump to post URLs and maintaining a sticky thread of 'useful' posts related to specific topics, it might cut down on repeat questions. I already have several very useful posts for LCD installation that would be handy to share with others.

Re: Is PID Autotune Still required?

Posted: Mon Mar 25, 2013 7:04 pm
by Flateric
I made a post about the search engine and it's "too common" issue in the past.

It really is annoying when you are unable to search for what you actually want to search for. I have only ever seen this issue in these forums and nowhere else. And I frequent and admin a number of different forums on the interwebs! :)

Re: Is PID Autotune Still required?

Posted: Mon Mar 25, 2013 8:23 pm
by mhackney
Yes, I run The Reelsmithing Forum and had to deal with this issue a few years ago. It's actually a simple configuration parameter but the guys did not enable it when I first brought it up last year.

Re: Is PID Autotune Still required?

Posted: Tue Mar 26, 2013 12:50 am
by Flateric
Really more of an annoyance than anything.

Especially since when you are trying to use it is generally when you are frustrated trying for help it seems. LOL